The Netter Collection of Medical Illustrations VOLUME 3_Dykhatelnaya_sistema

VOLUME 3

The Netter Collection

OF MEDICAL ILLUSTRATIONS:

Respiratory System

Second Edition

David A. Kaminsky, MD

Associate Professor
Pulmonary and Critical Care Medicine
University of Vermont
Burlington, Vermont

Illustrations by
Frank H. Netter, MD, and Carlos A.G. Machado, MD

CONTRIBUTING ILLUSTRATORS
John A. Craig, MD
James A. Perkins, MS, MFA
Kristen Wienandt Marzejon, MS, MFA
Tiffany S. DaVanzo, MA, CMI
Anita Impagliazzo, MA, CMI

1600 John F. Kennedy Blvd.
Ste 1800
Philadelphia, PA 19103-2899

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS: ISBN: 978-1-4377-0574-4
RESPIRATORY SYSTEM, Volume 3, Second Edition
Copyright © 2011 by Saunders, an imprint of Elsevier Inc.
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Notices

Knowledge and best practice in this field are constantly changing. As new research and experience
broaden our understanding, changes in research methods, professional practices, or medical
treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge in
evaluating and using any information, methods, compounds, or experiments described herein.
In using such information or methods they should be mindful of their own safety and the safety
of others, including parties for whom they have a professional responsibility.

With respect to any drug or pharmaceutical products identified, readers are advised to check the
most current information provided (i) on procedures featured or (ii) by the manufacturer of each
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of administration, and contraindications. It is the responsibility of practitioners, relying on their own
experience and knowledge of their patients, to make diagnoses, to determine dosages and the best
treatment for each individual patient, and to take all appropriate safety precautions.

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ISBN: 978-1-4377-0595-9

Acquisitions Editor: Elyse O’Grady
Developmental Editor: Marybeth Thiel
Editorial Assistant: Chris Hazle-Cary
Publishing Services Manager: Patricia Tannian
Senior Project Manager: John Casey
Designer: Lou Forgione

Printed in China
Last digit is the print number: 9 8 7 6 5 4 3 2 1

ABOUT THE SERIES

Dr. Frank Netter at work Dr. Frank H. Netter exemplified the distinct CUSHING’S SYNDROME IN A PATIENT WITH THE CARNEY COMPLEX
vocations of doctor, artist, and teacher.
The single-volume “blue book” that paved the way for the Even more important, he unified them. Netter’s Carney complex is characterized
multivolume Netter Collection of Medical Illustrations illustrations always began with meticulous by spotty skin pigmentation.
series, affectionately known as the “green books.” research into the forms of the body, a philoso- Pigmented lentigines and blue
phy that steered his broad and deep medical nevi can be seen on the face–
understanding. He often said, “Clarification is including the eyelids, vermillion
the goal. No matter how beautifully it is painted, borders of the lips, the
a medical illustration has little value if it does conjunctivae, the sclera–and the
not make clear a medical point.” His greatest labia and scrotum.
challenge—and greatest success—was charter- Additional features of the
ing a middle course between artistic clarity and Carney complex can include:
instructional complexity. That success is cap-
tured in this series, beginning in 1948, when Myxomas: cardiac atrium,
the first comprehensive collection of Netter’s cutaneous (e.g., eyelid),
work, a single volume, was published by CIBA and mammary
Pharmaceuticals. It met with such success that Testicular large-cell
over the following 40 years the collection was calcifying Sertoli cell tumors
expanded into an eight-volume series—each Growth-hormone
devoted to a single body system. secereting pituitary adenomas
Psammomatous
In this second edition of the legendary series, melanotic schwannomas
we are delighted to offer Netter’s timeless work,
now arranged and informed by modern text and PPNAD adrenal glands are usually of normal size and most are
radiologic imaging contributed by field-leading doctors studded with black, brown, or red nodules. Most of the pigmented
and teachers from world-renowned medical institutions nodules are less than 4 mm in diameter and interspersed in the
and supplemented with new illustrations created by adjacent atrophic cortex.
artists working in the Netter tradition. Inside the classic
green covers, students and practitioners will find A brand new illustrated plate painted by Carlos Machado,
hundreds of original works of art—the human body MD, for The Endocrine System, Volume 2, ed. 2
in pictures—paired with the latest in expert medical
knowledge and innovation, and anchored in the sublime Dr. Carlos Machado at work
style of Frank Netter.
Dr. Carlos Machado was chosen by Novartis to be
Dr. Netter’s successor. He continues to be the primary
artist contributing to the Netter family of products. Dr.
Machado says, “For 16 years, in my updating of the
illustrations in the Netter Atlas of Human Anatomy, as
well as many other Netter publications, I have faced
the challenging mission of continuing Dr. Netter’s
legacy, of following and understanding his concepts,
and of reproducing his style by using his favorite
techniques.”
Although the science and teaching of medicine
endures changes in terminology, practice, and discov-
ery, some things remain the same. A patient is a patient.
A teacher is a teacher. And the pictures of Dr. Netter—
he called them pictures, never paintings—remain the
same blend of beautiful and instructional resources that
have guided physicians’ hands and nurtured their imag-
inations for over half a century.
The original series could not exist without the dedi-
cation of all those who edited, authored, or in other
ways contributed, nor, of course, without the excellence
of Dr. Netter, who is fondly remembered by all who
knew him. For this exciting second edition, we also owe
our gratitude to the authors, editors, advisors, and
artists whose relentless efforts were instrumental in
adapting these timeless works into reliable references
for today’s clinicians in training and in practice. From
all of us at Elsevier, we thank you.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS v

ABOUT THE EDITOR

David A. Kaminsky, MD, is Associate Professor
of Pulmonary and Critical Care Medicine at
the University of Vermont College of Medicine.
He received his undergraduate degree from Yale
University, and medical degree from University of
Massachusetts Medical School. He completed his
residency training in Internal Medicine at Columbia
Presbyterian Medical Center in New York City, and
fellowship training in Pulmonary and Critical Care
Medicine at the University of Colorado Health Sci-
ences Center in Denver. He joined the faculty of the
University of Vermont College of Medicine in 1995
and continues to work as a clinician, researcher, and
educator. Dr. Kaminsky is the Clinical Director of
the Pulmonary Function Lab, Program Director for
the Fellowship Training Program in Pulmonary and
Critical Care, and Associate Chair of the Institutional
Review Board at University of Vermont. His areas of
research interest include pulmonary physiology, lung
mechanics, asthma, and COPD. His work has been
funded by the National Institutes of Health, the Ameri-
can Lung Association, the Whittaker Foundation, and
other agencies. Dr. Kaminsky has published nearly 40
original papers and a dozen book chapters and reviews.
He lives in the Burlington, Vermont, area with his wife
and two children, two cats, and dog. He enjoys many
outdoor activities, including running, hiking, sailing,
rowing, and ice hockey.

vi THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

PREFACE

It has been an honor to be the editor of the second am indebted to the many outstanding contributors to
edition—first major revision in 30 years—of Netter’s this edition, who are each international experts in their
Respiratory System. The changes that have occurred field. Without their input, it would have been impos-
over the past 3 decades in pulmonary medicine have sible to ensure that the most up-to-date, accurate infor-
been profound. The challenge of editing this edition mation would be provided to bring Netter’s Respiratory
has therefore been to include these updates while at the Disease into the 21st century. I would like to thank
same time preserving the unique nature and artistic especially those contributors who have been my teach-
beauty of Netter’s classic depiction of human health ers and mentors over the years: Drs. David Badesch,
and disease. In addition to ensuring the accuracy and Jason Bates, Gerry Davis, Barry Make, Ted Marcy,
relevance of the timeless topics of anatomy and physio- Polly Parsons, Charlie Irvin, Richard Irwin, Mike
logy, we have significantly revised the sections on Iseman, and Talmadge King. Special thanks also go to
airways, parenchymal and pleural diseases, lung cancer, Dr. Jeffrey Klein, who made extra efforts to provide
infectious diseases, thromboembolic disease, inhala- radiographic images for many different sections of the
tional diseases, acute respiratory distress syndrome, book. Finally, I want to dedicate this work to my grand-
pharmacotherapy, radiology, mechanical ventilation, father, Dr. Edward Budnitz, who shared with me his
and trauma and surgery. New sections have been love of medicine and inspired me to pursue a career as
created on pulmonary immunology, pulmonary hyper- a physician.
tension, lung manifestations of systemic disease, sleep
medicine, exhaled breath analysis, endobronchial ultra- David Kaminsky
sound, video-assisted thoracoscopic ultrasound, lung Burlington, Vermont
volume reduction surgery, and lung transplantation. I
November 2010

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS vii

ABOUT THE ARTIST FROM THE FIRST EDITION

The medical paintings of Dr. Frank Netter have undiminished. He is usually in his studio by in medical school, however, he found that because of
received such wide acclaim from physicians the 7:00 am, where he concentrates on the project his graphic training he could learn his subjects best by
world over for so long that the image of the man himself before him until about two o’clock. The making drawings. So his early medical illustrations were
has begun to take on mythical proportions. And, indeed, afternoons are mostly devoted to golf, to made for his own education. But it was not long before
it is easy to understand how such a transformation could swimming in the sea or pool, to fishing, to his drawings caught the eyes of his professors, who then
take place. Yet, Dr. Netter is a real human being who time with his family or friends, or to other kept him busy in what little spare time he had making
breathes, eats and carries on a daily routine just like the diversions. At times he takes a “postman’s illustrations for their books and articles. Netter gradu-
rest of us and who, for that matter, stands a little in awe holiday” to paint a landscape or a portrait just ated from New York University School of Medicine
of the image which is so often ascribed to him. for the fun of it. and completed his internship and surgical residency at
Bellevue Hospital in the depths of the great depression.
In order to help affirm his reality as a man, we asked But not all of Dr. Netter’s work is done at It soon became evident that his art commissions from
Dr. Netter to make the accompanying self-portrait of the drawing board. Much of it consists of publishers and pharmaceutical manufacturers were a
himself at work in his studio. The sketch portrays a intensive study and wide reading, observation better source of income than his depression-stifled
number of elements which may be familiar to those who of physicians at work in the clinic, hospital medical practice, and he made the decision to be a full-
have seen photographs of Dr. Netter’s studio in previ- or laboratory, and long hours of discussion time medical artist.
ous volumes of The Ciba Collection of Medical with a collaborator. Even during his hours of
Illustrations or in other publications—the man relaxation the concept of the illustrations is Dr. Netter’s association with the CIBA Pharmaceuti-
himself, the drawing board, the paints, the brushes, the germinating in his mind. After these prelimi- cal Company began in 1938 with his creation of a folder
skeleton and other accoutrements. The difference is naries he makes pencil sketches, composing cut out in the shape of a heart. Paintings of the anterior
in the background. No longer is it the skyline of the details and layout of the various elements of the and posterior (basal) surface of the heart were printed
New York, which could be seen from his former illustrations, positioning x-rays and photomicrographs, on the front and back and sections of the internal
studio window. Now it is the open sunny landscape of and determining the exact dimensions and placing of anatomy were depicted on the inside. An advertising
southern Florida, with waving palm trees and a boat the legends in order to achieve the maximum teaching message was overprinted both inside and out. The
traversing the waters of the intracoastal waterway. effect. Only after the sketches are checked, double immediate response of physicians to this piece was to
checked, and revised for accuracy and detail does he request that it be produced without the advertising
Nevertheless, the Netters’ move south from their proceed with the finished painting. Most of his paint- message. This was done to great success, and thus was
long established New York home does not signify an ings are in water color, but at times he has used other born a series of anatomy and pathology illustration
intention to wind down a highly productive work media including casein paint, chalks, acrylics or oils. projects, the demand for which was so great that it
schedule. Florida has meant a change in location and He maintains, however, that the medium is not very eventually led, in 1948, to the publication of the first
climate, but the intensity of Frank Netter’s commit- important. Good pictures can be made in any medium. book of The Ciba Collection of Medical Illustra-
ment to what has become his life’s work continues He prefers water color only because through long use tions. The year 1978, then, is not only the year of
he feels more at home with it and because he can introduction of Volume 7, Respiratory System, but is
express himself more directly and work more rapidly also the thirtieth anniversary of the first book of The
with it. Ciba Collection of Medical Illustrations. Coinci-
Dr. Netter’s great facility and skill at representative dentally, it is also the thirtieth anniversary of the first
painting, gift though it may be, did not come to fruition issue of the Ciba Clinical Symposia series.
without dedicated study and training—not only in
drawing and painting but in graphic design, composi- Dr. Netter is still preparing well over 100 paintings
tion and layout as well. From the time he was a little a year for The Ciba Collection of Medical Illustra-
boy he wanted to be an artist. He studied intensively at tions and Clinical Symposia. Even now he is well into
the National Academy of Design, the Art Students the task of illustrating a new atlas on the musculo-
League of New York and other outstanding schools as skeletal system. Much has been said and written in the
well as with private teachers. He won many honors and, past about the Netter “genius.” Perhaps the most
indeed, became a successful commercial artist in the impressive aspect of all is not his “genius,” but the use
heyday of that profession. But then, partly because of this remarkable artist-physician-teacher makes of his
his own interest and partly because of urging by his gifts. His collective works are monumental, and they
family to do “something more serious” he decided to continue to grow.
give up art and initiate a new career in medicine. Once
Philip B. Flagler

viii THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

INTRODUCTION TO THE FIRST EDITION

Whenever a new atlas of mine appears, I feel as a manifestations of pulmonary vascular obstruction have
woman must feel when she has just had a baby. been more clearly defined.
The tediousness and travail of the long pregnancy and
the pain of delivery are over, and it remains to be seen In light of the foregoing examples of the changing
how my offspring will fare in the world. emphasis in the field of pulmonary medicine, to which
many more could be added, I have tried in this atlas to
In this case, there were a number of problems during give to each topic its proper emphasis in relation to the
the gestation. One of these was that interest in the subject as a whole, in accord with current concepts. In
respiratory system and its diseases has not only greatly doing this, much consideration had to be given to space
increased in recent years but that its focus has been availability. A good public speaker must deliver the
radically altered. The reasons for these changes are essentials of his message within the time allotted to him
manifold. They include the great differences which for if he rambles on and on, his audience is lost and his
have come about in the incidence of various lung dis- message ineffective. So, too, the artist must portray
eases; the advent and better utilization of antibiotics; his subject matter as effectively as possible within the
advances in radiologic technique and interpretation; the allotted pages. What to leave out becomes, at times, as
development of additional diagnostic techniques such important as what to include. Without such considera-
as radioactive isotope scanning; expansion in the study tions, this volume might have grown to twice or three
of pulmonary physiology and application of pulmonary times its size and become unbalanced, or become so
function tests; progress in understanding of pulmonary crowded with minutiae as to be dull and boring. In
pathology; increased facility in thoracic surgery and the either event, the utility of the book would have been
development of methods for predetermining operabil- greatly impaired.
ity, such as mediastinoscopy; the design or improve-
ment of technical and diagnostic mechanisms such as As in the preparation of all my previous atlases, my
oxygen and aerosol apparatus, mechanical ventilators, major efforts in this work were again necessarily
more efficient spirometers and surgical staplers; and directed towards gathering, absorbing and digesting the
alterations in the personal habits, environment and information about each subject so that I might properly
average age of the population. portray it. Thus study, learning and analysis of the
subject matter became as time consuming, or more so,
All these factors, as well as others, are, however, than the actual painting of the pictures. One cannot
interactive. For example, the great decrease in inci- intelligently portray a subject unless one understands it.
dence of pulmonary tuberculosis is related to the advent My goal was to picture or diagram the essence of each
of antibiotics: but it is also a consequence of improve- subject, avoiding the incidental or inconsequential. In
ment in living standards and habits, as well as of some instances I have, however, included topics which,
improved early diagnosis. These factors may also be at present, do not seem to have great practical applica-
responsible for the lesser incidence and morbidity of tion but which, in the future, may give important clues
pneumococcal pneumonia. Whereas in former years to pathogenesis, diagnosis or treatment. All this was
these two diseases were major concerns of the chest greatly facilitated, indeed made possible, through the
physician, they are nowadays of much less significance. devoted cooperation of the many distinguished consult-
But this, on the other hand, has allowed more time and ants who are listed individually on other pages of this
effort to be diverted to other lung disorders. The volume. I herewith express my appreciation to each and
greatly increased incidence of lung cancer appears to every one of them for the time, effort and guidance
have resulted in considerable measure from changes which they gave me, and for the knowledge which they
in personal habits (such as smoking), environmental imparted to me. I also thank the many others who,
pollution and occupational activity, and possibly also although not officially consultants, nevertheless helped
change in population age. But earlier discovery of me with advice or information or by supplying refer-
tumors through greater public awareness and improved ence material to me. They are also credited elsewhere
diagnosis, plus greater surgical facility, have led to in this book. I especially thank Dr. Matthew B. Divertie
increased interest in operability, and this in turn has for his careful and thorough review of both the pictorial
stimulated study of pathologic classification in relation and text material and for his many constructive
to malignancy. The increase in chronic bronchitis and suggestions.
emphysema, while largely real and attributable to the
same etiologic factors as cancer, may to some extent be The production of this book involved a tremendous
only apparent—due to better diagnostic methods and amount of organizational work, such as assembling and
utilization of pulmonary function studies. But recogni- compiling the material as it grew in volume, correlating
tion of some of the etiologic factors and better under- illustrations and text, grammatical checking, reference
standing of the underlying pathologic processes, checking, type specification, page layout, proofreading,
coupled with availability and utilization of such meas- and a multitude of mechanical and practical details inci-
ures as aerosol medication, improved equipment for dental to publication. I tremendously admire the effi-
oxygen administration and mechanical ventilation, and ciency with which these matters were handled by Mr.
postural drainage have greatly modified for the better Philip Flagler and his staff at CIBA, including Ms. Gina
the management of these distressing disorders. The Dingle, Ms. Barbara Bekiesz, Ms. Kristine Bean and
current relatively high incidence of occupational dis- Mr. Pierre Lair. Finally, I once more give praise to the
eases may likewise to some extent be only apparent, CIBA Pharmaceutical Company and its executives for
because of greater awareness and better diagnosis. Pul- their vision in sponsoring this project and for the free
monary embolus and infarction have also received hand they have given me in executing it. I have tried to
increased attention in recent years as the common do justice to it.
sources of emboli have been identified, and as the
FRANK H. NETTER, MD

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS ix

ADVISORY BOARD

Gillian Ainslie, MBChB, MRCP, FRCP John E. Heffner, MD
Associate Professor and Acting Head William M. Garnjobst Chair of Medical Education
Respiratory Clinic, Groote Schuur Hospital Pulmonary and Critical Care Medicine
University of Cape Town Lung Institute Providence Portland Medical Center
Cape Town, South Africa Oregon Health and Sciences University
Portland, Oregon
Koichiro Asano, MD
Division of Pulmonary Surinder K. Jindal, MD, FCCP
Shinjuku-ku, Tokyo, Japan Professor and Head, Department of Pulmonary

Eric D, Bateman, MBChB, MD, FRCP, DCH Medicine
Professor of Respiratory Medicine Postgraduate Institute of Medical Education
Respiratory Clinic, Groote Schuur Hospital
University of Cape Town Lung Institute and Research
Cape Town, South Africa Chandigarh, India

Dr. Santos Guzmán López
Jefe del Depto. de Anatomía
Universidad Autónoma de Nuevo León
Fac. de Medicina
Monterrey, Nuevo Leon, Mexico

x THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

CONTRIBUTORS

Steven H. Abman, MD Gerald S. Davis, MD Richard S. Irwin, MD
Professor Professor of Medicine Professor of Medicine
Department of Pediatrics, Section of Pulmonology Pulmonary Disease and Critical Care Medicine University of Massachusetts Medical School
University of Colorado School of Medicine and University of Vermont College of Medicine Chair, Critical Care
Fletcher Allen Health Care UMass Memorial Medical Center
The Children’s Hospital Burlington, Vermont Worcester, Massachusetts
Aurora, Colorado Plates 4-103 to 4-113 Plate 4-10
Plates 1-33 to 1-43
Malcolm M. DeCamp, MD Michael Iseman, MD
David B. Badesch, MD Fowler-McCormick Professor of Surgery Professor of Medicine
Professor of Medicine Northwestern University Feinberg School National Jewish Medical and Research Center
Division of Pulmonary Sciences and Critical Care Denver, Colorado
of Medicine Plates 4-93 to 4-102
Medicine and Cardiology Chief, Division of Thoracic Surgery
Clinical Director, Pulmonary Hypertension Center Northwestern Memorial Hospital James R. Jett, MD
University of Colorado Denver Chicago, Illinois Professor of Medicine
Aurora, Colorado Plates 3-26, 5-25 to 5-33 National Jewish Medical and Research Center
Plates 4-114 to 4-126 Denver, Colorado
Raed A. Dweik, MD Plates 4-48 to 4-63
Peter J. Barnes DM, DSc, FRCP, Director, Pulmonary Vascular Program
FMedSci, FRS Department of Pulmonary and Critical Marc A. Judson, MD
Head of Respiratory Medicine Professor of Medicine
National Heart and Lung Institute Care Medicine Division of Pulmonary and Critical Care Medicine
Imperial College Cleveland Clinic Medical University of South Carolina
London, England, UK Cleveland, Ohio Charleston, South Carolina
Plates 2-22 to 2-24, 5-1 to 5-10 Plate 3-20 Plates 4-155 and 4-156

Jason H.T. Bates, PhD, DSc David Feller-Kopman, MD David A. Kaminsky, MD
Professor of Medicine, Physiology, Biophysics Director, Interventional Pulmonology Associate Professor
University of Vermont College of Medicine Associate Professor of Medicine Pulmonary and Critical Care Medicine
Burlington, Vermont The Johns Hopkins Hospital University of Vermont College of Medicine
Plates 2-14 to 2-21 Baltimore, Maryland Burlington, Vermont
Plates 3-21 to 3-25, 5-15 to 5-17, 5-20 to 5-23 Plates 3-1 to 3-3, 5-18
Kevin K. Brown, MD
Professor of Medicine Alex H. Gifford, MD Greg King, MB, ChB, PhD, FRACP
Vice Chairman, Department of Medicine Fellow, Pulmonary and Critical Care Medicine Head of Imaging Group
Director, Interstitial Lung Disease Program Dartmouth-Hitchcock Medical Center The Woolcock Institute of Medical Research
National Jewish Medical and Research Center Lebanon, New Hampshire Department of Respiratory Medicine
Denver, Colorado Plates 2-25 to 2-31 Royal North Shore Hospital
Plates 4-157 to 4-162 St. Leonards, Australia
Curtis Green, MD Plates 4-163 and 4-164
Vito Brusasco, MD Professor of Radiology and Cardiology
Professor of Respiratory Medicine University of Vermont College of Medicine Talmadge E. King, Jr., MD
University of Genoa Staff Radiologist Julius R. Krevans Distinguished Professorship in
Genoa, Italy Fletcher Allen Health Care
Plates 2-8 to 2-13 Burlington, Vermont Internal Medicine
Plates 3-4 to 3-19 Chair, Department of Medicine
Nancy A. Collop, MD University of California, San Francisco
Professor of Sleep Medicine and Neurology Anne Greenough MD (Cantab), MB BS, San Francisco, California
Director, Emory Sleep Program DCH, FRCP, FRCPCH Plates 4-147 to 4-154
Emory University Division of Asthma Allergy and Lung Biology,
Atlanta, Georgia Jeffrey Klein, MD
Plates 4-165 and 4-166 MRC, and Asthma Director, Thoracic Radiology
UK Centre in Allergic Mechanisms of Asthma Fletcher Allen Health Care
Bryan Corrin, MD, FRCPath King’s College London Professor
Professor Emeritus of Pathology Neonatal Centre University of Vermont College of Medicine
London University King’s College Hospital Burlington, Vermont
Honorary Senior Clinical Research Fellow Denmark Hill Plates 3-4 to 3-19
National Heart and Lung Institute London, England, UK
Imperial College Plates 4-1 to 4-9, 4-144, 4-145 Kevin O. Leslie, MD
Honorary Consultant Pathologist Professor of Pathology
Royal Brompton Hospital Charles G. Irvin, PhD Mayo Clinic Arizona
London, England, UK Vice Chairman for Research Scottsdale, Arizona
Plates 1-1 to 1-16 Department of Medicine Plates 1-17 to 1-31
Director, Vermont Lung Center
THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS Professor, Departments of Medicine and Molecular xi

Physiology & Biophysics
University of Vermont College of Medicine
Burlington, Vermont
Plates 2-1 to 2-7

Contributors

Donald A. Mahler, MD Michael S. Niederman, MD Steven Sahn, MD
Professor of Medicine Chairman, Department of Medicine Professor of Medicine
Pulmonary and Critical Care Medicine Winthrop-University Hospital Division of Pulmonary, Critical Care, Allergy,
Dartmouth Medical School Mineola, New York;
Dartmouth-Hitchcock Medical Center Professor of Medicine and Sleep Medicine
Lebanon, New Hampshire Vice-Chairman, Department of Medicine Medical University of South Carolina
Plates 2-25 to 2-31 SUNY at Stony Brook Charleston, South Carolina
Stony Brook, New York Plates 4-129 to 4-134
Barry Make, MD Plates 4-64 to 4-83
Professor of Medicine Sanjay Sethi, MD
National Jewish Medical and Research Center Paul M. O’Byrne, MB, FRCPI, FRCPC Professor, Department of Medicine
Denver, Colorado E.J. Moran Campbell Professor and Chair Chief, Division of Pulmonary, Critical Care, and
Plates 5-11 to 5-14 Department of Medicine
McMaster University Sleep Medicine
Theodore W. Marcy, MD, MPH Hamilton, Ontario, Canada University at Buffalo, SUNY
Professor of Medicine Plates 4-14 to 4-27 Section Chief, Division of Pulmonary, Critical Care
Pulmonary Disease and Critical Care Medicine Unit
University of Vermont College of Medicine Polly E. Parsons, MD and Sleep Medicine
Burlington, Vermont E. L. Amidon Professor of Medicine Western New York VA HealthCare System
Plates 4-127, 4-128, 5-24 Chair, Department of Medicine Buffalo, New York
Director, Pulmonary and Critical Care Medicine Plates 4-84 to 4-92
James G. Martin, MD, DSc University of Vermont College of Medicine
Director, Meakins Christie Laboratories Medicine Health Care Service Leader Damon A. Silverman, MD
Professor of Medicine Fletcher Allen Health Care Assistant Professor of Otolaryngology
McGill University Burlington, Vermont University of Vermont College of Medicine
Montreal, Quebec, Canada Plate 4-146 Director, The Vermont Voice Center
Plate 1-32 Fletcher Allen Health Care
Burlington, Vermont
Deborah H. McCollister, RN Plates 4-11 to 4-13, 5-19
University of Colorado Health Sciences Center
Denver, Colorado Elena Pollina, MD Robert A. Wise, MD
Plates 4-114 to 4-126 Department of Histopathology
King’s College Hospital Professor of Medicine and Environmental Health
Meredith C. McCormack, MD, MHS London, England, UK Sciences
Assistant Professor of Medicine Plates 4-1 to 4-9
Division of Pulmonary and Critical Care Medicine Division of Pulmonary and Critical Care Medicine
Johns Hopkins University Catheryne J. Queen Johns Hopkins University
Baltimore, Maryland Mycobacterial and Respiratory Diseases Division Johns Hopkins Asthma & Allergy Center
Plates 4-28 to 4-42 National Jewish Health Medical and Research Center Baltimore, Maryland
Denver, Colorado Plates 4-28 to 4-42
Ernest Moore, MD Plates 4-93 to 4-102
Professor and Vice Chairman
Department of Surgery Margaret Rosenfeld, MD, MPH
University of Colorado Denver
Bruce M. Rockwell Distinguished Chair in Trauma Medical Director, Pulmonary Function Laboratory
Chief of Surgery Seattle Children’s
Denver Health Associate Professor of Pediatrics
Denver, Colorado University of Washington School of Medicine
Plates 4-135 to 4-143 Seattle, Washington
Plates 4-43 to 4-47

xii THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

CONTENTS

SECTION 1 SECTION 2 3-10 Images from a PET-CT Scanner, 91
3-11 Patterns of Lobar Collapse: Right Lung
ANATOMY AND EMBRYOLOGY PHYSIOLOGY
PULMONARY MECHANICS AND (After Lubert and Krause), 92
1-1 Respiratory System, 3 GAS EXCHANGE 3-12 Patterns of Lobar Collapse: Left Lung
1-2 Bony Thorax, 4
1-3 Rib Characteristics and Costovertebral 2-1 Muscles of Respiration, 49 (After Lubert and Krause), 93
2-2 Spirometry: Lung Volume and 3-13 Alveolar Versus Interstitial Disease, 94
Articulations, 5 3-14 Distribution of Pulmonary Nodules, 95
1-4 Anterior Thoracic Wall, 6 Measurement, 50 3-15 Alveolar Disease, 96
1-5 Anterior Thoracic Wall (cont’d), 7 2-3 Determination of Functional Residual 3-16 Radiographic Consolidation Patterns of
1-6 Anterior Thoracic Wall: Internal View, 8
1-7 Dorsal Aspect of the Thorax, 9 Capacity (FRC), 51 Each Segment of Lungs (AP Views), 97
1-8 Dorsal Aspect of the Thorax: Posterior 2-4 Forces During Quiet Breathing, 52 3-17 Solitary Pulmonary Nodule, 98
2-5 Measurement of Elastic Properties of 3-18 Airway and Pleural Diseases, 99
and Lateral View, 10 3-19 Abnormalities of the Chest Wall and
1-9 Intercostal Nerves and Arteries, 11 the Lung, 53
1-10 Diaphragm (Viewed from Above), 12 2-6 Surface Forces In the Lung, 54 Mediastinum, 100
1-11 Topography of the Lungs (Anterior 2-7 Elastic Properties of the Respiratory
3-20 Exhaled Breath Analysis, 101
View), 13 System: Lung and Chest Wall, 55
1-12 Topography of the Lungs (Posterior 2-8 Distribution of Airway Resistance, 56 ENDOSCOPIC PROCEDURES
2-9 Patterns of Airflow, 57
View), 14 2-10 Expiratory Flow, 58 3-21 Flexible Bronchoscopy, 102
1-13 Medial Surface of the Lungs, 15 2-11 Forced Expiratory Vital Capacity 3-22 Bronchoscopic Views, 103
1-14 Bronchopulmonary Segments, 16 3-23 Nomenclature for Peripheral
1-15 Bronchopulmonary Segments in Maneuver, 59
2-12 Work of Breathing, 60 Bronchi, 104
Relationship to Ribs, 17 2-13 Pleural Pressure Gradient and Closing 3-24 Rigid Bronchoscopy, 105
1-16 Relationships of the Trachea and Main 3-25 Endobronchial Ultrasonography, 106
Volume, 61 3-26 Mediastinotomy and Mediastinoscopy, 107
Bronchi, 18 2-14 Distribution of Pulmonary Blood Flow, 62
1-17 Bronchial Arteries, 19 2-15 Pulmonary Vascular Resistance, 63 SECTION 4
1-18 Mediastinum: Right Lateral View, 20 2-16 Pathways and Transfers of O2 and
1-19 Mediastinum: Left Lateral View, 21 DISEASES AND PATHOLOGY
1-20 Innervation of the Lungs and CO2, 64 CONGENITAL LUNG DISEASE
2-17 Blood Gas Relationships During
Tracheobronchial Tree, 22 4-1 Congenital Deformities of the
1-21 Structure of the Trachea and Major Normal Ventilation and Alveolar Thoracic Cage, 1111
Hypoventilation, 65
Bronchi, 23 2-18 Ventilation-Perfusion Relationships, 66 4-2 Pathology of Kyphoscoliosis, 112
1-22 Intrapulmonary Airways, 24 2-19 Shunts, 67 4-3 Pulmonary Function in
1-23 Structure of Bronchi and Bronchioles— 2-20 Oxygen Transport, 68
2-21 Role of Lungs and Kidneys in Regulation Kyphoscoliosis, 113
Light Microscopy, 25 of Acid-Base Balance, 69 4-4 Congenital Diaphragmatic Hernia, 114
1-24 Ultrastructure of the Tracheal, Bronchial, 2-22 Response to Oxidant Injury, 70 4-5 Tracheoesophageal Fistulas and

and Bronchiolar Epithelium, 26 LUNG METABOLISM Tracheal Anomalies, 115
1-25 Bronchial Submucosal Glands, 27 4-6 Pulmonary Agenesis, Aplasia, and
1-26 Intrapulmonary Blood Circulation, 28 2-23 Inactivation of Circulating Vasoactive
1-27 Fine Structure of Alveolar Capillary Unit: Substances, 71 Hypoplasia, 116
4-7 Congenital Lung Cysts, 117
Ultrastructure of Pulmonary Alveoli and 2-24 Activation of Circulating Precursors of 4-8 Pulmonary Sequestration, 118
Capillaries, 29 Vasoactive Substances, 72 4-9 Congenital Lobar Emphysema, 119
1-28 Fine Structure of Alveolar Capillary Unit:
Type II Alveolar Cell and Surface-Active CONTROL AND DISORDERS OF 4-10 Chronic Cough, 120
Layer, 30 RESPIRATION
1-29 Fine Structure of Alveolar Capillary Unit: LARYNGEAL DISORDERS
Pulmonary Vascular Endothelium, 31 2-25 Chemical Control of Respiration (Feedback
1-30 Lymphatic Drainage of the Lungs and Mechanism), 73 4-11 Common Laryngeal Lesions, 121
Pleura, 32 4-12 Laryngeal and Tracheal Stenosis, 122
1-31 Lymphatic Drainage of the Lungs and 2-26 Neural Control of Breathing, 74 4-13 Vocal Cord Dysfunction, 123
Pleura: Distribution of Lymphatics in 2-27 Respiratory Response to Exercise, 75
Lungs and Pleura, 33 2-28 Effects of High Altitude on Respiratory BRONCHIAL ASTHMA
1-32 Pulmonary Immunology: Lymphocytes,
Mast Cells, Eosinophils, and Mechanism, 76 4-14 Allergic Asthma: Clinical Features, 124
Neutrophils, 34 2-29 Hyperventilation and Hypoventilation, 77 4-15 Nonallergic Asthma: Clinical
2-30 Periodic Breathing (Cheyne-Stokes), 78
DEVELOPMENT OF THE LOWER 2-31 Sites of Pathologic Disturbances in Features, 125
RESPIRATORY SYSTEM 4-16 Common Precipitating Factors in
Control of Breathing, 79
1-33 Developing Respiratory Tract and Etiology of Bronchial Asthma, 126
Pharynx, 35 SECTION 3 4-17 Variable Airflow Obstruction and Airway

1-34 Respiratory System at 5 to 6 Weeks, 36 DIAGNOSTIC PROCEDURES Hyperresponsiveness, 127
1-35 Respiratory System at 6 to 7 Weeks, 37 4-18 Sputum in Bronchial Asthma, 128
1-36 Larynx, Tracheobronchial Tree, and Lungs 3-1 to 3-3 Tests of Pulmonary Function, 82 4-19 Skin Testing for Allergy, 129
4-20 Representative Differential Diagnosis of
at 7 to 10 Weeks, 38 RADIOLOGIC EXAMINATION
1-37 Sagittal Section at 6 to 7 Weeks, 39 OF THE LUNGS Bronchial Asthma, 130
1-38 Transverse Section at 5 to 8 Weeks, 40 4-21 Blood Gas and pH Relationships, 131
1-39 Diaphragm at 5 to 6 Weeks, 41 3-4 Normal Posteroanterior (PA) and Lateral 4-22 Airway Pathophysiology in
1-40 Terminal Air Tube, 42 Views of Chest, 85
1-41 Alveolar-Capillary Relationships at Age 8 Asthma, 132
3-5 Lateral Decubitus View, 86 4-23 Mechanism of Type 1 (Immediate)
Years, 43 3-6 Technique of Helical Computed
1-42 Surfactant Effects, 44 Hypersensitivity, 133
1-43 Physiology of the Perinatal Pulmonary Tomography (CT), 87 4-24 Pathology of Severe Asthma, 134
3-7 Right Bronchial Tree as Revealed by 4-25 General Management Principles for
Circulation, 45
Bronchograms, 88 Allergic Asthma, 135
3-8 Left Bronchial Tree as Revealed by 4-26 Mechanism of Asthma Medications, 136
4-27 Emergency Department Management of
Bronchograms, 89
3-9 Pulmonary Angiography, 90 Asthma, 137

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS xiii

Contents

CHRONIC OBSTRUCTIVE VIRAL COMMUNITY-ACQUIRED 4-120 Massive Embolization, 230
PULMONARY DISEASE PNEUMONIA 4-121 Mechanical Defenses Against and

4-28 Interrelationships of Chronic Bronchitis 4-73 Influenza Virus and its Epidemiology, 183 Chronic Effects of Pulmonary
and Emphysema, 138 4-74 Influenza Pneumonia, 184 Embolism, 231
4-75 Varicella Pneumonia, 185 4-122 Special Situations and Extravascular
4-29 Emphysema, 139 4-76 Cytomegalovirus Pneumonia, 186 Sources of Pulmonary Emboli, 232
4-30 Chronic Bronchitis, 140 4-77 Severe Acute Respiratory Syndrome
4-31 Mixed Chronic Bronchitis and PULMONARY HYPERTENSION
(SARS), 187
Emphysema, 141 4-78 Lung Abscess, 188 4-123 WHO Classification System of
4-32 Cor Pulmonale Caused by COPD, 142 4-79 Lung Abscess (cont’d), 189 Pulmonary Hypertension, 233
4-33 Chronic Obstructive Pulmonary 4-80 Overview of Health Care–Associated
4-124 Pathology of Pulmonary Hypertension, 234
Disease, 143 Pneumonia, Hospital-Acquired 4-125 Diagnosis of Pulmonary Hypertension, 235
4-34 Anatomic Distribution of Emphysema, 144 Pneumonia, and Ventilator-Associated 4-126 Therapy for Pulmonary Hypertension, 236
4-35 Centriacinar (Centrilobular) Pneumonia, 190
4-81 Testing for Suspected Hospital-Acquired PULMONARY EDEMA
Emphysema, 145 Pneumonia, 191
4-36 Panacinar (Panlobular) Emphysema, 146 4-82 Pneumonia in the Compromised Host, 192 4-127 Pulmonary Edema: Pathway of Normal
4-37 COPD: Inflammation, 147 4-83 Pneumonia in the Compromised Host Pulmonary Fluid Resorption, 237
4-38 COPD: Protease-Antiprotease (cont’d), 193
4-84 Actinomycosis, 194 4-128 Pulmonary Edema: Some Etiologies
Imbalance, 148 4-85 Nocardiosis, 195 and Hypotheses of Mechanisms, 238
4-39 Pulmonary Function in Obstructive 4-86 Histoplasmosis, 196
4-87 Histoplasmosis (cont’d), 197 PLEURAL EFFUSION
Disease, 149 4-88 Coccidioidomycosis, 198
4-40 Pathophysiology of Emphysema: Loss of 4-89 Blastomycosis, 199 4-129 Pathophysiology of Pleural Fluid
4-90 Paracoccidioidomycosis, 200 Accumulation, 239
Elastic Recoil and Hyperinflation, 150 4-91 Cryptococcosis, 201
4-41 High-Resolution CT Scan of Lungs in 4-92 Aspergillosis, 202 4-130 Pleural Effusion in Heart Disease, 240
4-131 Unexpandable Lung, 241
COPD, 151 TUBERCULOSIS 4-132 Parapneumonic Effusion, 242
4-42 Summary of COPD Treatment 4-133 Pleural Effusion in Malignancy, 243
4-93 Dissemination of Tuberculosis, 203 4-134 Chylothorax, 244
Guidelines, 152 4-94 Evolution of Tubercle, 204
4-95 Initial (Primary) Tuberculosis THORACIC TRAUMA
BRONCHIECTASIS
Complex, 205 4-135 Rib and Sternal Fractures, 245
4-43 Bilateral Severe Bronchiectasis, 153 4-96 Progressive Pathology, 206 4-136 Flail Chest and Pulmonary
4-44 Localized Bronchiectasis, 154 4-97 Extensive Cavitary Disease, 207
4-98 Miliary Tuberculosis, 208 Contusion, 246
CYSTIC FIBROSIS 4-99 Tuberculin Testing, 209
4-100 Sputum Examination, 210 PNEUMOTHORAX
4-45 Pathophysiology and Clinical 4-101 Sputum Culture, 211
Manifestations of Cystic Fibrosis, 155 4-102 Nontuberculous Mycobacterial Lung 4-137 Tension Pneumothorax, 247
4-138 Open (Sucking) Pneumothorax, 248
4-46 Radiographic and Gross Anatomic in Disease, 212 4-139 Hemothorax, 249
Findings of the Lung Cystic 4-140 Pulmonary Laceration, 250
Fibrosis, 156 LUNG DISEASES CAUSED BY 4-141 Tracheobronchial Rupture, 251
THE INHALATION OF PARTICLES 4-142 Traumatic Asphyxia, 252
4-47 Cystic Fibrosis: Clinical Aspects, 157 AND FUMES 4-143 Diaphragmatic Injuries, 253

LUNG CANCER OVERVIEW 4-103 Overview of Inhalation Diseases, 213 RESPIRATORY DISTRESS
4-104 Silicosis, 214 SYNDROME
4-48 Classification of Bronchogenic 4-105 Silicosis (cont’d), 215
Carcinoma, 158 4-106 Coal Worker’s Pneumoconiosis, 216 4-144 Respiratory Distress Syndrome, 254
4-107 Asbestosis and Asbestos-Related 4-145 Respiratory Distress Syndrome
4-49 Lung Cancer Staging, 159
4-50 Squamous Cell Carcinoma of Diseases, 217 (cont’d), 255
4-108 Asbestosis Asbestos-Related Diseases 4-146 Acute Lung Injury, 256
the Lung, 160
4-51 Adenocarcinoma of the Lung, 161 (cont’d), 218 INTERSTITIAL LUNG DISEASES
4-52 Large Cell Carcinomas of the Lung, 162 4-109 Beryllium, 219
4-53 Small Cell Carcinomas of the Lung, 163 4-110 Pneumoconiosis Caused by Various 4-147 Idiopathic Interstitial Pneumonias, 257
4-54 Superior Vena Cava Syndrome, 164 4-148 Idiopathic Interstitial Pneumonias
4-55 Pancoast Tumor and Syndrome, 165 Minerals and Mixed Dusts, 220
4-111 Pneumoconiosis Caused by Various (cont’d), 258
PARANEOPLASTIC MANIFESTATIONS 4-149 Idiopathic Interstitial Pneumonias
OF LUNG CANCER Minerals and Mixed Dusts (cont’d), 221
4-112 Hypersensitivity Pneumonitis, 222 (cont’d), 259
4-56 Endocrine Manifestations of Lung 4-113 Hypersensitivity Pneumonitis 4-150 Cryptogenic Organizing Pneumonia, 260
Cancer, 166 4-151 Pulmonary Alveolar Proteinosis, 261
(cont’d), 223 4-152 Idiopathic Pulmonary
4-57 Neuromuscular and Connective Tissue
Manifestations, 167 PULMONARY EMBOLISM AND Hemosiderosis, 262
VENOUS THROMBOEMBOLISM 4-153 Lymphangioleiomyomatosis, 263
4-58 Other Neoplasms of the Lung, 168 4-154 Pulmonary Langerhans Cell
4-59 Benign Tumors of the Lung, 169 4-114 Predisposing Factors for Pulmonary
4-60 Malignant Pleural Mesothelioma, 170 Embolism, 224 Histiocytosis, 264
4-61 Mediastinal Tumors: Anterior 4-155 Sarcoidosis, 265
4-115 Sources of Pulmonary Emboli, 225 4-156 Sarcoidosis (cont’d), 266
Mediastinum, 171 4-116 Clinical Manifestations of Leg Vein 4-157 Rheumatoid Arthritis, 267
4-62 Middle-Posterior and Paravertebral 4-158 Systemic Sclerosis (Scleroderma), 268
Thrombosis, 226 4-159 Systemic Lupus Erythematosus, 269
Mediastinum, 172 4-117 Ultrasound and CT in Diagnosis of Acute 4-160 Dermatomyositis and Polymyositis, 270
4-63 Pulmonary Metastases, 173 4-161 Pulmonary Vasculitis, 271
Venous Thromboembolism, 227 4-162 Eosinophilic Pneumonia, 272
PNEUMONIA 4-118 Embolism of Lesser Degree Without
4-163 Pulmonary Manifestations of Other
4-64 Overview of Pneumonia, 174 Infarction, 228 Diseases, 273
4-65 Pneumococcal Pneumonia, 175 4-119 Pulmonary Infarction, 229
4-66 Pneumococcal Pneumonia (cont’d), 176 4-164 Pulmonary Manifestations of Other
Diseases (cont’d), 274
ATYPICAL PATHOGEN PNEUMONIA
4-165 Sleep Medicine, 275
4-67 Mycoplasmal Pneumonia, 177 4-166 Sleep-Disordered Breathing, 276
4-68 Chlamydophila Psittaci Pneumonia, 178
4-69 Legionella Pneumonia, 179
4-70 Staphylococcus Aureus Pneumonia, 180
4-71 Haemophilus Influenzae Pneumonia, 181
4-72 Gram–Negative Bacterial Pneumonia, 182

xiv THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Contents OXYGEN THERAPY 5-23 Endotracheal Suction, 300

SECTION 5 5-12 Oxygen Therapy in Acute Respiratory 5-24 Mechanical Ventilation, 301
Failure, 289
THERAPIES AND THERAPEUTIC LUNG SURGERY
PROCEDURES 5-13 Methods of Oxygen Administration, 290
PULMONARY PHARMACOLOGY 5-14 Oxygen Therapy in Chronic Respiratory 5-25 Tracheal Resection and Anastomosis, 302
5-26 Removal of Mediastinal Tumors, 303
5-1 Bronchodilators, 278 Failure (Ambulatory and Home Use), 291 5-27 Sublobar Resection and Surgical
5-2 Methylxanthines, 279
5-3 Methylxanthines: Adverse Effects, 280 AIRWAY MANAGEMENT Lung Biopsy, 304
5-4 Anticholinergics, 281 5-28 Lobectomy, 305
5-5 Corticosteroid Actions in Bronchial 5-15 Introduction of Chest Drainage Tubes, 292 5-29 Pneumonectomy, 306
5-16 Chest-Draining Methods, 293 5-30 Pneumonectomy (cont’d), 307
Asthma, 282 5-17 Postural Drainage and Breathing 5-31 Video-Assisted Thoracoscopic Surgery, 308
5-6 Corticosteroids: Clinical Uses, 283 5-32 Lung Volume Reduction Surgery, 309
5-7 Adverse Effects of Corticosteroids, 284 Exercises, 294 5-33 Lung Transplantation, 310
5-8 Leukotrienes, 285 5-18 Upper Airway Obstruction and the
5-9 Antileukotrienes, 286 SELECTED REFERENCES, 311
5-10 Cough Suppressants (Antitussive Heimlich Maneuver, 295
5-19 Securing an Emergent Airway, 296 INDEX, 317
Agents), 287 5-20 Endotracheal Intubation, 297
5-21 Tracheostomy, 298
5-11 Pulmonary Rehabilitation, 288 5-22 Morbidity of Endotracheal Intubation and

Tracheostomy, 299

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS xv

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SECTION 1

ANATOMY AND
EMBRYOLOGY

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Plate 1-1 Anatomy and Embryology

Pituitary gland Falx cerebri
Pons Sphenoidal sinus
Dura mater
Medulla oblongata Frontal sinus
Nasopharynx
Oropharynx Nasal cavity Nasal turbinates
Laryngopharynx (hypopharynx) (conchae)
Esophagus Superior and
Cupula (dome) of pleura supreme
Clavicle
Middle
Inferior

Nasal vestibule
Ostium of auditory tube
Oral cavity
Tongue
Epiglottis
Larynx

1st rib Vocal fold (cord)
Subcostal parietal pleura Trachea
Subclavian artery and vein
Mediastinal parietal pleura Aorta
Left pulmonary artery
Right main bronchus Left main bronchus
Lymph nodes
Visceral pleura over right lung Pericardium
Right pulmonary artery Sternum (cut away)
Hilus of right lung 6th and 7th costal cartilages
Pericardial mediastinal pleura Rectus abdominis muscle
Diaphragmatic parietal pleura Linea alba
Diaphragm Internal oblique muscle
External oblique muscle (cut away)

Substernal and subcostal parietal pleura

RESPIRATORY SYSTEM the ribs in inspiration and expiration. The muscles of to the same degree of individual variation that affects
the anterolateral abdominal wall are also accessory all anatomic structures. The illustrations depict the
The respiratory system is made up of the structures to forceful expiration (their contraction forces the most common situations encountered. No attempt is
involved in the exchange of oxygen and carbon dioxide diaphragm upward by pressing the contents of the made to describe all of the many variations that occur.
between the blood and the atmosphere, so-called exter- abdominal cavity against it from below) and are used in
nal respiration. The exchange of gases between the “abdominal” respiration. Certain muscles of the neck An important and clinically valuable concept that is
blood in the capillaries of the systemic circulation and can elevate the ribs, thus enlarging the anteroposterior worth emphasizing at this point is the convention of
the tissues in which these capillaries are located is diameter of the thorax, and under some circumstances, subdividing each lung into lobes and segments on the
referred to as internal respiration. the muscles attaching the arms to the thoracic wall can basis of branching of the bronchial tree. From the
also help change the capacity of the thorax. standpoint of its embryologic development, as well as
The respiratory system consists of the external nose, of its function as a fully established organ of respiration,
internal nose, and paranasal sinuses; the pharynx, which In Plates 1-1 through 1-16, the anatomy of the res- the lung is indeed the ultimate branching of the main
is the common passage for air and food; the larynx, piratory system and significant accessory structures is bronchus that leads into it. Knowledge of the subdivi-
where the voice is produced; and the trachea, bronchi, shown. It is important not only to visualize these struc- sion of the lung on this basis is essential to anatomists,
and lungs. Accessory structures necessary for the opera- tures in isolation but also to become familiar with their physiologists, pathologists, radiologists, surgeons, and
tion of the respiratory system are the pleurae, dia- blood supply, nerve supply, and relationships with both chest physicians because without this three-dimensional
phragm, thoracic wall, and muscles that raise and lower adjacent structures and the surface of the body. One key, there is no exact means of precisely localizing
should keep in mind that these relationships are subject lesions within the respiratory system.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 3

Plate 1-2 Respiratory System

Anterior view

Jugular notch

Manubrium

Acromion 1 Angle Sternum
Body
Coracoid process 2

Scapula Glenoid cavity 3 Xiphoid
Neck process
4
Scapular notch
5
Subscapular fossa
6
BONY THORAX Clavicle 7 11
True ribs (1–7) 8 12
The skeletal framework of the thorax—the bony Costal cartilages 9
thorax—consists of 12 pairs of ribs and their cartilages, False ribs (8–12) 10
12 thoracic vertebrae and intervertebral discs, and the
sternum. The illustration also includes one clavicle and Floating ribs (11–12)
scapula because these bones serve as important attach-
ments for some of the muscles involved in respiration. Posterior view Clavicle

The sternum is made up of three parts—the manu- Head 1 Acromion Scapula
brium, body, and xiphoid process. The manubrium and Neck 2
body are not in quite the same plane and thus form the Rib Tubercle 3 Supraspinous
sternal angle at their junction, a significant landmark at Angle 4 fossa
which the costal cartilage of the second rib articulates Body
with the sternum. The superior border of the manu- 5 Spine
brium is slightly concave, forming what is called the Floating ribs (11–12) 6
suprasternal notch. Infraspinous
7 fossa
The costal cartilages of the first through seventh ribs
ordinarily articulate with the sternum and are called 8 True ribs (1–7)
true ribs. The costal cartilages of the eighth through 9
tenth ribs ( false ribs) are usually attached to the carti- False ribs (8–12)
lage of the rib above, and the ventral ends of the carti- 10
lages of the eleventh and twelfth ribs ( floating ribs) have
no direct skeletal attachment. 11
12
All of the ribs articulate dorsally with the vertebral
column in such a way that their ventral end (together The clavicle articulates at its medial end with the The vertebral levels of the bony landmarks on the
with the sternum) can be raised slightly, as occurs in superolateral aspect of the manubrium of the sternum ventral aspect of the thorax are variable and differ
inspiration. The articulations of the costal cartilages and at its lateral end with the medial edge of the somewhat with the phase of respiration. In general, the
with the sternum, except those of the first rib, are true acromion process of the scapula. Its medial two-thirds upper border of the manubrium is at the level of the
or synovial joints that allow more freedom of movement are curved slightly anteriorly, and its lateral third is second to third thoracic vertebrae, the sternal angle
than there would be without this type of articulation. curved posteriorly. Muscular attachments to the medial opposite the fourth to fifth thoracic vertebrae, and the
and lateral parts of the clavicle leave its middle portion xiphisternal junction at the level of the ninth thoracic
The deep surface of the scapula (the subscapular less protected and thus readily subject to fracture. vertebra.
fossa) fits against the posterolateral aspect of the thorax
over the second to seventh ribs, where, to a great extent,
it is held by the muscles that are attached to it. The
acromion process of the scapula articulates with the
lateral end of the clavicle; this acts as a strut to hold
the lateral angle of the scapula away from the thorax.
On the dorsal surface of the scapula, a spine protrudes
and continues laterally into the acromion process. At
its vertebral end, the spine flattens into a smooth tri-
angular surface with the base of the triangle at the
vertebral border. The spine separates the supraspinous
fossa from the infraspinous fossa. Three borders of the
scapula are described—superior, lateral, and medial or
vertebral. On the superior border is a notch or incisura,
and lateral to this, the coracoid process protrudes
anteriorly.

The lateral angle of the scapula presents a slight
concavity, the glenoid fossa, for articulation with the
head of the humerus. At the superior end of the glenoid
fossa is the supraglenoid tuberosity, and at its inferior
margin is the infraglenoid tuberosity.

4 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-3 Anatomy and Embryology

1st rib viewed from above Head Red ϭ muscle origins
Neck Blue ϭ muscle insertions
Grooves for Tubercle
Subclavius subclavian
muscle vein and artery

Scalenus Scalenus Head Head
anterior medius Neck Tubercle Neck
muscle Tubercle
1st digitation; Angle Superior; inferior
2nd rib Articular facets
viewed 2nd digitation Scalenus for vertebrae
from above of serratus posterior

anterior muscle

Angle

Costovertebral ligaments viewed Costal groove
from right posterior

RIB CHARACTERISTICS Transverse process Articular facet for transverse process
AND COSTOVERTEBRAL (cut off )
ARTICULATIONS
Radiate ligament

A typical rib has a head, a neck, and a body. The head Costotransverse (neck) ligament
articulates with one or two vertebral bodies (see below). Lateral costotransverse (head) ligament
A tubercle at the lateral end of the relatively short neck
articulates with the transverse process of the lower of Superior costotransverse (neck) ligament
the two vertebrae with which the head of the rib articu- Intertransverse ligament
lates. As the body is followed anteriorly, the “angle” of
the rib is formed. At the inferior border of the body is Costovertebral ligaments viewed from above
the costal or subcostal groove, partially housing the
intercostal artery, vein, and nerve. Each rib is continued Radiate ligament
anteriorly by a costal cartilage by which it is attached
either directly or indirectly to the sternum, except for Interarticular ligament Synovial
the eleventh and twelfth ribs, which have no sternal Superior articular facet cavities
attachment. Superior costotransverse ligament (cut off)
Lateral costotransverse (head) ligament
The first and second ribs differ from the typical rib
and therefore need special description. The first rib— Costotransverse (neck) ligament
the shortest and most curved of all the ribs—is quite
flat, and its almost horizontal surfaces face roughly articulation of the head of the rib, the intraarticular The first and the last two (or three) ribs each has a
superiorly and inferiorly. On its superior surface are ligament and the capsular ligament, with a thickening single articular facet that makes contact with an impres-
grooves for the subclavian artery and subclavian vein, of its anterior part forming the radiate ligament; and sion on the side of the thoracic vertebra of the same
separated by a tubercle for the attachment of the for the costotransverse joint, the thin capsular ligament, number. No intraarticular ligament is present, so there
scalenus anterior muscle. the lateral costotransverse ligament between the lateral is just a single synovial cavity, in contrast to the two
part of the tubercle of the rib and the tip of the trans- synovial cavities present for the, typical rib. The lowest
The second rib is a good deal longer than the first, verse process, and the superior costotransverse liga- ribs do not have synovial joints between their tubercles
but its curvature is very similar to the curvature of the ment attached to the transverse process of the rib above. and the transverse processes of the related vertebrae.
first rib. The angle of the second rib, which is close to
the tubercle, is not at all marked. Its external surface
faces to some extent superiorly but a bit more outward
than that of the first rib.

The typical articulation of a rib with the vertebral
column involves both the head and tubercle of the rib.
The head has two articular facets—the superior facet
making contact with the vertebral body above and the
inferior one with the vertebral body below. Between
these, the head of the rib is bound to the intervertebral
disc by the intraarticular ligament. The articular facet
on the tubercle of the rib contacts the transverse process
of the lower of the two vertebrae. These are true or
synovial joints, with articular cartilages, joint capsules,
and synovial cavities. The articulations of the first,
tenth, eleventh, and twelfth ribs are each with only one
vertebra, the vertebra of the same number.

The ligaments related to the typical articulation of
a rib with the vertebral column are as follows: for

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 5

Plate 1-4 Respiratory System

Sternocleidomastoid muscle Sternothyroid muscle
Posterior triangle of neck Sternohyoid muscle Invested by cervical fascia
Omohyoid muscle
Trapezius muscle
Clavicle
Perforating branches of internal Subclavius muscle invested
thoracic artery and anterior cutaneous by clavipectoral fascia
branches of intercostal nerves
Thoracoacromial artery
Pectoralis major muscle (pectoral branch) and
lateral pectoral nerve
Cephalic vein
Costocoracoid ligament
Acromion
Coracoid process
Deltoid
muscle Medial
pectoral
ANTERIOR THORACIC WALL nerve
1

The anterior thoracic wall is covered by skin and the 2
superficial fascia, which contains the mammary glands. 3
Its framework is formed by the anterior part of the bony 4
thorax, described and illustrated in Plate 1-2. 5

The muscles here belong to three groups: muscles Long thoracic nerve and 6 Pectoralis
of the upper extremity, muscles of the anterolateral lateral thoracic artery minor muscle
abdominal wall, and intrinsic muscles of the thorax (see 7 invested by
Plates 1-4, 1-5, and 1-6). Latissimus dorsi muscle 8
9 Clavipectoral
MUSCLES OF THE UPPER EXTREMITY Digitations of serratus 10 fascia
anterior muscle
These muscles include the pectoralis major, pectoralis Digitations
minor, serratus anterior, and subclavius. Lateral cutaneous of serratus anterior
branches of intercostal muscle
The pectoralis major is a thick, fan-shaped muscle that nerves and posterior
has three areas of origin: clavicular, sternocostal, and intercostal arteries External intercostal
abdominal. The clavicular origin is the anterior surface membranes anterior
of roughly the medial half of the clavicle. The sterno- External oblique muscle to internal intercostal
costal origin is the anterior surface of the manubrium muscles
and body of the sternum and the costal cartilages of the Anterior layer of rectus sheath
first six ribs. The small and variable abdominal origin External intercostal
is the aponeurosis of the external abdominal oblique Sternalis muscle (inconstant) muscles
muscle. The pectoralis major inserts onto the crest of
the greater tubercle of the humerus. Linea alba Body and xiphoid
process of sternum
The pectoralis minor is a thin triangular muscle that MUSCLES OF THE ANTEROLATERAL
lies deep to the pectoralis major. It arises from the ABDOMINAL WALL Internal oblique muscle
superior margins and external surfaces of the third, These muscles, which are partially on the anterior tho-
fourth, and fifth ribs close to their costal cartilages and racic wall, are the external abdominal oblique and the Rectus abdominis muscle
from the fascia covering the intervening intercostal rectus abdominis.
muscles. The pectoralis minor inserts onto the coracoid Cutaneous branches of thoracoabdominal
process of the scapula. The pectoralis major and minor The external abdominal oblique muscle originates by (abdominal portions of intercostal) nerves
muscles are supplied by the medial and lateral anterior fleshy digitations from the external surfaces and inferior and superior epigastric artery
thoracic (pectoral) nerves, which are branches of the borders of the fifth to twelfth ribs. The fasciculi from
medial and lateral cords of the brachial plexus. the last two ribs insert into the iliac crest, and the the aponeuroses of the external oblique, the internal
remaining fasciculi end in an aponeurosis that inserts in oblique, and the transverse abdominis muscles. Its infe-
The serratus anterior is a large muscular sheet that the linea alba. rior end is attached to the crest of the pubis.
curves around the thorax. It arises by muscular digita-
tions from the external surfaces and superior borders of The superior end of the rectus abdominis muscle is The muscles of the anterolateral abdominal wall are
the first eight or nine ribs and from the fascia covering attached primarily to the external surfaces of the costal supplied by the thoracoabdominal branches of the
the intervening intercostal muscles. It inserts onto the cartilages of the fifth, sixth, and seventh ribs. The rectus lower six thoracic nerves.
ventral surface of the vertebral border of the scapula. abdominis muscle is enclosed in a sheath formed by
Its nerve supply is the long thoracic nerve, a branch of INTRINSIC MUSCLES OF THE THORAX
the brachial plexus (fifth, sixth, and seventh cervical
nerves), which courses inferiorly on the external surface These muscles, which help to form the anterior tho-
of the muscle. racic wall, are the external and internal intercostal
muscles and the transversus thoracis muscle.
The subclavius is a small triangular muscle tucked
between the clavicle and the first rib. It has a tendinous The external intercostal muscles each arise from the
origin from the junction of the first rib and its costal lower border of the rib above and insert onto the upper
cartilage, and it inserts into a groove toward the lateral border of the rib below. Their fibers are directed down-
end of the lower surface of the clavicle. It receives its ward and medially. They extend from the tubercles of
nerve supply from the subclavian branch of the brachial
plexus.

6 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-5 Anatomy and Embryology

Internal jugular vein

Omohyoid, sternothyroid, and sternohyoid muscles Levator scapulae muscle
Clavicle
Anterior Scalene
Subclavius muscle muscles
Trapezius muscle Middle

Posterior

Thoracoacromial artery Phrenic nerve
Coracoid process Thoracic duct

ANTERIOR THORACIC WALL Cephalic vein Brachial plexus

(Continued) Pectoralis major Subclavian
muscle (cut) artery and vein

Deltoid Axillary
muscle artery
and vein

the ribs to the beginnings of the costal cartilages, from 1

which they continue medially as the anterior intercostal

membranes. The internal intercostal muscles each arise 2

from the inner lip and floor of the costal groove of the

rib above and from the related costal cartilage. They 3
insert onto the upper border of the rib below. These

muscles extend from the sternum to the angles of the

ribs, from which they continue to the vertebral column Intercostobrachial 4 Superior
as the posterior intercostal membranes. The fibers of nerve thoracic
the internal intercostal muscles are directed downward artery

and laterally. The innermost intercostal muscles are deep Pectoralis 5 Internal
to the internal intercostals, of which they were once minor muscle thoracic
artery
regarded a constituent. They attach to the internal and veins

aspects of adjoining ribs and their fibers run in the same Long thoracic 6 External
direction as those of the internal intercostals. The nerve and lateral intercostal
intercostal muscles are supplied by the related inter- thoracic artery muscle

costal nerves. 7 Internal
A muscle occasionally present, the sternalis, lies on Digitations of serratus intercostal
muscle (cut)
the origin of the pectoralis major muscle parallel to the anterior muscle 8
sternum. Its variable attachments are to the costal car- Transversus
tilages, sternum, rectus sheath, and sternocleidomastoid Lateral cutaneous thoracis
branches of intercostal muscle
and pectoralis major muscles. 9
nerves and posterior 10 Anterior
On the inner surface of the anterior thoracic wall lies intercostal arteries intercostal
a thin sheet of muscular and tendinous fibers called the branches
of internal
transversus thoracis muscle. This muscle arises from the External intercostal muscles thoracic artery
posterior surfaces of the xiphoid process, the lower
Transversus abdominis muscle
third of the body of the sternum, and the sternal ends

of the related costal cartilages. It is inserted by muscular External intercostal

slips onto the inner surfaces of the second or third to membranes anterior

the sixth costal cartilages. to internal intercostal

muscles

NERVES OF THE ANTERIOR Internal oblique muscle Musculophrenic artery and vein
THORACIC WALL Intercostal nerve
Rectus abdominis Superior epigastric arteries and veins
The nerve supply of the skin of the anterior thoracic muscle and sheath (cut)
wall has two sources: the anterior and middle supracla-
vicular nerves (branches of the cervical plexus made up arteries come from the back of the aorta and run branches of the internal thoracic (internal mammary)
mostly of fibers from the fourth cervical nerve) cross forward in the lower nine intercostal spaces. Also pos- artery, of which there are two in each of the upper five
over the clavicle to supply the skin of the infraclavicular teriorly, the first intercostal space receives the highest or six spaces.
area; the anterior and lateral cutaneous branches of the intercostal branch of the costocervical trunk from the
related intercostal nerves pierce the muscles to supply subclavian artery. This same artery anastomoses with VEINS OF THE ANTERIOR
the skin of the remainder of the anterior thoracic wall. the highest aortic intercostal artery, contributing to the THORACIC WALL
supply of the second intercostal space. Near the angle
ARTERIES OF THE ANTERIOR of the rib, each aortic intercostal artery gives off a col- Similar to venous drainage elsewhere, that of the ante-
THORACIC WALL lateral intercostal branch that descends to run forward rior thoracic wall exhibits considerable variation. The
along the upper border of the rib below the intercostal most frequent pattern involves the veins accompanying
Arteries supplying the anterior thoracic wall come from space. These arteries anastomose with the intercostal the internal thoracic (internal mammary) arteries and
several sources. There is typically an artery in the upper
part of the intercostal space and one in the lower part
of the space. Posteriorly, nine pairs of intercostal

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 7

Plate 1-6 Respiratory System

Internal view

Sternothyroid muscle Manubrium of sternum
Sternohyoid muscle Common carotid artery
Inferior thyroid artery
Internal jugular vein
Vertebral artery
Anterior scalene muscle Brachiocephalic trunk
Brachiocephalic vein
Brachiocephalic vein Subclavian artery and vein

Subclavian artery and vein Internal thoracic
artery and vein
Phrenic nerve and
pericardiacophrenic Anterior intercostal
artery and vein arteries and veins
and intercostal nerve
Clavicle (cut)
Internal intercostal
Internal thoracic muscles
artery and vein

Anterior 1
intercostal 2
arteries
and veins
and intercostal
nerve

Perforating 3 Innermost
branches 4 intercostal
of internal muscles
thoracic artery
ANTERIOR THORACIC WALL and vein and Transversus
anterior thoracis
(Continued) cutaneous 5 muscle
branch of
the azygos, hemiazygos, and accessory hemiazygos intercostal
veins. The veins accompanying the internal thoracic nerve
arteries receive tributaries corresponding to the arterial
branches and empty into the brachiocephalic (innomi- Collateral 6
nate) veins of the same side. The first posterior inter- branches of Musculo-
costal vein usually empties into either the brachiocephalic intercostal phrenic
(innominate) or the vertebral vein. The right highest artery
intercostal vein usually drains blood from the second and vein 7 artery
and third intercostal spaces and passes inferiorly to and vein
empty into the azygos vein. The left highest intercostal Body of
vein also receives the second and third posterior inter- sternum 8
costal veins and empties into the lower border of the
left brachiocephalic vein. Diaphragm 9

The fourth to the eleventh posterior intercostal veins Slips of Transversus abdominis muscle
on the right side empty into the azygos vein, which costal origin Internal thoracic artery and veins
is ordinarily formed by the junction of the right ascend- of diaphragm Superior epigastric artery and veins
ing lumbar vein and the right subcostal vein. The
latter courses superiorly on the right side of the tho- Transversus abdominis muscle
racic vertebrae to the level of the fourth posterior Sternocostal triangle
intercostal vein, where it passes in front of the root Sternal part of diaphragm
of the lung to empty into the superior vena cava just Xiphoid process
before this vessel enters the pericardial sac. On the
left side, the ascending lumbar vein and the subcostal LYMPHATIC DRAINAGE OF THE diaphragm, and there is an intercostal node or two at
vein form the hemiazygos vein, which usually receives ANTERIOR THORACIC WALL the vertebral end of each intercostal space. The effer-
the lower four posterior intercostal veins as it runs ents of the sternal nodes usually empty into the bron-
superiorly to the left of the vertebral column. Here The lymphatic drainage of the anterior thoracic wall chomediastinal trunk. The efferents of the phrenic
it crosses at about the level of the ninth thoracic ver- involves three general groups of lymph nodes: sternal nodes ordinarily go to the sternal nodes. The upper
tebra to empty into the azygos vein. The accessory (internal thoracic), phrenic (diaphragmatic), and inter- intercostal nodes send their efferents to the thoracic
hemiazygos vein receives the fourth to the eighth pos- costal. The sternal nodes lie along the superior parts of duct, and the lower ones on each side drain into a vessel
terior intercostal veins as it courses inferiorly to the the internal thoracic arteries. There are several groups that courses inferiorly into the cisterna chyli.
left of the vertebral column before crossing at about of phrenic nodes on the superior surface of the
the level of the eighth thoracic vertebra, also emptying
into the azygos vein.

8 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-7 Anatomy and Embryology

Superior nuchal line Splenius capitis muscle
External occipital protuberance Accessory nerve (XI)

Posterior triangle of neck Levator scapulae muscle
Sternocleidomastoid muscle Rhomboid minor muscle
Rhomboid major muscle
Trapezius muscle

Spine of scapula Supraspinatus muscle

Infraspinous fascia Infraspinatus muscle

Teres minor Spine and
muscle acromion of scapula

Deltoid Teres minor
muscle T1 muscle

DORSAL ASPECT OF T6 Spinous
THE THORAX processes
Teres major muscle T12 of thoracic
The dorsal aspect of the thorax is also covered by skin vertebrae
and superficial fascia, with the cutaneous nerves to the Latissimus Medial Teres major
skin of the back ramifying in the latter. These cutane- dorsi muscle Lateral muscle
ous nerves are branches of the posterior primary divi-
sions (dorsal rami) of the thoracic nerves—for the upper External Latissimus dorsi
six thoracic levels the medial branch and for the lower oblique muscle (cut)
six the lateral branch. muscle
Lower digitations of
The more superficial muscles on the posterior aspect Lumbar triangle serratus anterior muscle
of the thorax belong to the group connecting the upper (Petit) with
extremity to the vertebral column. They are the trape- internal oblique Digitations of external
zius, latissimus dorsi, rhomboideus major, rhomboideus muscle in its floor oblique muscle
minor, and levator scapulae.
Iliac crest Serratus posterior inferior muscle
The trapezius muscle arises from about the medial
third of the superior nuchal line, the external occipital rotation at the shoulder joint and helps to depress the Thoracolumbar fascia over deep
protuberance and the posterior margin of the ligamen- raised arm against resistance. muscles of back (erector spinae)
tum nuchae, and the spinous processes of the seventh Posterior cutaneous branches (from medial
cervical and all of the thoracic vertebrae and the related The rhomboideus major and minor muscles are often and lateral branches of dorsal rami of thoracic
supraspinous ligaments. The lower fibers converge into difficult to separate. The rhomboideus major arises spinal nerves)
an aponeurosis that slides over the triangular area at the from the tips of the spinous processes and supraspinous
medial end of the spine of the scapula and is attached ligaments of the second to fifth thoracic vertebrae. Its angle. The rhomboideus minor muscle arises from the
at the apex of this triangle. The middle group of fibers insertion is into the vertebral border of the scapula via spinous processes of the first thoracic and last cervical
is inserted on the medial margin of the acromion and a tendinous arch running from the lower angle of the vertebrae and the lower part of the ligamentum nuchae
the upper margin of the posterior border of the spine smooth triangle at the root of the spine to the inferior and is inserted into the vertebral border of the scapula
of the scapula. The upper group of fibers ends on the at the base of the triangle, forming the root of the
posterior border of the lateral third of the clavicle. The scapular spine. The rhomboideus muscles are supplied
trapezius is supplied by the spinal part of the eleventh by fibers from the fifth and sixth cervical nerves by
cranial nerve and branches from the anterior divisions way of the dorsoscapular branch of the brachial plexus.
(ventral rami) of the third and fourth cervical nerves. The rhomboideus major and minor muscles tend to
When contracting, the muscle tends to pull the scapula
medially while at the same time rotating it, thus carry-
ing the shoulder superiorly. If the shoulder is fixed, the
upper fibers tilt the head so that the face goes upward
toward the opposite side.

The latissimus dorsi muscle has a broad origin—by a
small muscular slip from the outer lip of the iliac crest
just lateral to the sacrospinalis muscle and by an exten-
sive aponeurosis attached to the spinous processes of
the lower six thoracic vertebrae, the lumbar and sacral
vertebrae, and the related supraspinous ligaments. This
muscle is inserted into the depth of the intertubercular
groove of the humerus. Its nerve supply comes from the
sixth, seventh, and eighth cervical nerves by way of
the thoracodorsal branch of the brachial plexus. This
muscle helps with extension, adduction, and medial

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 9

Plate 1-8 Respiratory System

Posterior view Splenius capitis and cervicis muscles
Posterior scalene muscle
Spinous process Serratus posterior superior muscle
of T1 vertebra

External External intercostal muscles
intercostal
muscles Thoracolumbar fascia over erector spinae muscle

Erector spinae muscle cut away
to reveal levatores costarum
and transversospinales muscles

Serratus posterior inferior muscle

Digitations of external oblique muscle

DORSAL ASPECT OF Transversus Internal oblique muscle
THE THORAX (Continued) abdominis Tendon of origin of transversus abdominis muscle
muscle
Levator scapulae muscle
Spinous process of L2 vertebra Accessory nerve (XI)

Lateral view Scapula
(retracted)
draw the scapula toward the vertebral column and Phrenic nerve
slightly superiorly, with the lower fibers of the major Teres major
muscles helping to rotate the scapula so that the shoul- Scalene muscles Anterior muscle
der is depressed. Middle Subscapularis muscle
Posterior
The levator scapulae muscle originates in four tendi- Long thoracic nerve
nous slips attached to the transverse processes of the Brachial plexus
first four cervical vertebrae. Its insertion is the vertebral same side. They are supplied by branches of the poste-
border of the scapula from its superior angle to the Subclavian artery and vein rior primary divisions of the middle and lower cervical
smooth triangle at the medial end of the spine scapula. nerves.
Its nerve supply is primarily by cervical plexus branches Superior thoracic artery
from the ventral rami of the third and fourth cervical The groove lateral to the spinous processes of the
nerves. The levator scapulae, as the name indicates, External intercostal membrane thoracic vertebrae is filled by the sacrospinalis muscle,
elevates the scapula, drawing it medially and rotating it anterior to internal intercostal muscle which is covered by the thoracic part of the lumbodor-
so that the tip of the shoulder is depressed. sal fascia. Deep to the sacrospinalis muscle lie the short
Perforating branch of internal vertebrocostal and intervertebral muscles; they are not
Just deep to the group of muscles connecting the thoracic artery and anterior described here.
upper extremity to the vertebral column lie the serratus cutaneous branch of intercostal nerve
posterior superior and serratus posterior inferior
muscles. Intercostobrachial nerve

The serratus posterior superior muscle has an origin via External intercostal muscle
a thin aponeurosis attached to the lower part of the
ligamentum nuchae and to the spinous processes and Lateral thoracic artery
related supraspinous ligaments of the seventh cervical Lateral cutaneous branches
and upper two or three thoracic vertebrae. It is inserted of intercostal nerves and
by fleshy digitations into the upper borders of the posterior intercostal arteries
second to fifth ribs lateral to their angles. This muscle
helps to increase the size of the thoracic cavity by Serratus anterior muscle
elevating the ribs. The serratus posterior inferior muscle
arises by means of a thin aponeurosis from the spinous insert by tendinous fasciculi onto the transverse proc-
processes and related supraspinous ligaments of the last esses of the upper two or three cervical vertebrae. The
two thoracic vertebrae and the first two or three lumbar splenius capitis muscle arises from the inferior half of
vertebrae. This muscle inserts by fleshy digitations the ligamentum nuchae and the spinous processes of
into the lower borders of the last four ribs, just beyond the seventh cervical and the first three or four thoracic
their angles. It tends to pull the last four ribs downward vertebrae. It is inserted onto the occipital bone just
and outward. The serratus posterior muscles receive inferior to the lateral third of the superior nuchal line.
branches of the ventral rami of the thoracic nerves at The splenius muscles tend to pull the head and neck
the levels at which they are located. backward and laterally and to turn the face toward the

Just deep to the serratus posterior superior muscle lie
the thoracic portions of the splenius cervicis and capitis
muscles.

The splenius cervicis muscle has a tendinous origin
from the spinous processes of the third to sixth thoracic
vertebrae and wraps around the deeper muscles to

10 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-9 Anatomy and Embryology

Erector spinae muscle Dorsal root Trapezius Rhomboid major muscle
(spinal) ganglion muscle Erector spinae muscle
Dorsal ramus of thoracic nerve Medial branch Scapula
Lateral branch Ventral root

Serratus anterior muscle

Intercostal nerve (ventral Thoracic aorta Infraspinatus muscle
ramus of thoracic spinal nerve)
Right posterior Subscapularis muscle
Internal intercostal intercostal
membrane deep to arteries (cut) Serratus anterior muscle
external intercostal muscle
Posterior intercostal artery
Costotransverse ligament
Internal intercostal membrane
Gray and white
rami communicantes Dorsal branch of posterior
intercostal artery
Sympathetic trunk
and ganglia Spinal (radicular, or segmental
medullary) branch of posterior
Innermost intercostal muscle intercostal artery

Lateral cutaneous branch Lateral cutaneous branch
of intercostal nerve of posterior intercostal artery

Internal intercostal muscle Innermost intercostal muscle

External intercostal muscle Internal intercostal muscle

Anterior branch of Sternum External intercostal muscle
lateral cutaneous Superior epigastric artery
branch of External oblique muscle
intercostal nerve
Internal thoracic artery
External oblique muscle
External intercostal membrane
Pectoralis major muscle
Anterior intercostal arteries
Transversus thoracis muscle Perforating branch
Anterior cutaneous branch of intercostal nerve Rectus abdominis muscle

INTERCOSTAL NERVES AND the ganglia of the sympathetic trunk and the thoracic posterior branch. At the anterior end of the intercostal
ARTERIES nerves of the same level, join the ventral ramus near space, the intercostal nerve ends by becoming the ante-
its origin. rior cutaneous nerve, which divides into a lateral branch
The typical thoracic spinal nerve is formed by the junc- and a shorter and smaller medial branch.
tion of a dorsal root and a ventral root near the inter- The dorsal ramus of the thoracic nerve, passing pos-
vertebral foramen below the vertebra having the same teriorly, pierces the erector spinae muscle (which it The aorta, lying on the anterior aspect of the verte-
number as the nerve. The dorsal root is made up of a supplies), the trapezius muscle, and the other superficial bral bodies, gives off pairs of posterior (aortic) intercos-
series of rootlets that emerge from one segment of muscles of the back (depending on the level) to reach tal arteries. The right posterior intercostal arteries lie
the spinal cord between its dorsal and lateral white the superficial fascia. There it divides into a smaller on the anterior aspect and the right side of the vertebral
columns; it contains the nerve cell bodies of the afferent medial branch and a longer lateral cutaneous branch, bodies as they travel to reach the intercostal spaces of
neurons that enter the spinal cord through it. This col- which supply the skin. the right side. The right and left posterior intercostal
lection of nerve cell bodies causes a swelling of the root, arteries course forward in the upper part of the inter-
named the dorsal root ganglion. A series of rootlets com- The ventral ramus of the thoracic nerve is the inter- costal spaces between the intercostal vein above and the
posed of axons of ventral-born gray cells leaves the costal nerve of that particular level (for the twelfth intercostal nerve below to anastomose with the anterior
same segment of the cord between the lateral and thoracic nerve, the subcostal nerve). From the seventh intercostal branches of the internal thoracic and muscu-
ventral white columns to form the ventral root of the to the eleventh thoracic levels, the ventral rami of the lophrenic arteries. Collateral branches run in the infe-
spinal nerve. thoracic nerves continue from the intercostal spaces rior parts of the intercostal space.
into the anterior abdominal wall. The intercostal nerve
The dorsal and ventral roots join near the interver- runs forward in the thoracic wall between the inner- To reach the pleural cavity from the outside at the
tebral foramen to make up the very short common trunk most intercostal muscle and the internal intercostal anterolateral aspect of the thorax, a needle would pass
of the spinal nerve, which divides almost immediately muscle. It lies inferior to the intercostal vein and inter- through the following layers: skin, superficial fascia,
into the dorsal ramus (posterior primary division) and costal artery and gives off a collateral branch to the intercostal muscles and related deep fascial layers, sub-
the ventral ramus (anterior primary division). The lower part of the space, as do the vein and artery. pleural fascia, and parietal layer of the pleura. If the
white and gray rami communicantes, which connect The intercostal nerve has a lateral cutaneous branch at needle is carefully inserted near the lower part of the
the lateral aspect of the thorax that pierces the overlying intercostal space (i.e., above the rib margin), one is
intercostal muscles to reach the subcutaneous tissue. reasonably sure of avoiding the intercostal nerve and
There it divides into an anterior (mammary) and a vessels.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 11

Plate 1-10 Respiratory System

Right sympathetic trunk Neck of rib

Costal part of parietal pleura Left sympathetic trunk
T8–T9 intervertebral disc
Left greater thoracic
Right greater thoracic splanchnic nerve
splanchnic nerve
Hemiazygos vein
Azygos vein
Mediastinal pleura
Thoracic duct
Thoracic (descending) aorta
Esophagus
Left leaflet of central tendon
Right leaflet
of central tendon Mediastinal part of parietal
Inferior vena cava pleura and pericardium (cut)
(receiving hepatic veins)
Diaphragmatic part of
Diaphragmatic part of parietal pleura (cut away)
parietal pleura (cut away)
Left phrenic nerve and
Right phrenic nerve pericardiacophrenic
and pericardiacophrenic artery and vein
artery and vein
Middle leaflet of central tendon
Mediastinal part of parietal covered by pericardium
pleura and pericardium (cut) Pericardium

Right costodiaphragmatic recess of pleural cavity Sternum Left costomediastinal
Right internal thoracic artery and veins recess of pleural cavity
Right costomediastinal recess of pleural cavity
Anterior mediastinum Transversus thoracis muscle
Left internal thoracic artery and veins
5th costal cartilage

DIAPHRAGM (VIEWED FROM lumbar vertebral bodies and related intervertebral vertebra. It transmits the aorta, azygos vein, and tho-
ABOVE) discs—to the first three on the right and the first two racic duct.
on the left. The medial lumbocostal arch, a thickening
The diaphragm is a curved musculotendinous septum of the fascia covering the psoas major muscle, extends The esophageal aperture is located at the level of the
separating the thoracic from the abdominal cavity, from the side of the body of the first or second lumbar tenth thoracic vertebra in the fleshy part of the dia-
forming the floor of the thoracic cavity with its convex vertebra to the front of the transverse process of the phragm. It transmits the esophagus, the right and left
upper surface facing the thorax. The dome of the dia- first (sometimes also the second) lumbar vertebra. The vagus nerves, and small esophageal arteries and veins.
phragm on the right side is as high as the fifth costal lateral lumbocostal arch, passing across the quadratus
cartilage (varying with the phase of respiration) and on lumborum muscle, extends from the transverse process The inferior vena caval aperture is situated at the level
the left is only slightly lower, so that some of the of the first lumbar vertebra to the tip and lower border of the disc between the eighth and ninth thoracic ver-
abdominal viscera are covered by the thoracic cage. of the twelfth rib. tebrae at the junction of the right and middle leaflets
of the central tendon. It is traversed by the inferior vena
The origin of the diaphragm is from the outlet of From the extensive origin just described, the fibers cava and some branches of the right phrenic nerve.
the thorax and has three parts: sternal, costal, and converge to insert in a three-leafed central tendon.
lumbar. Contraction of the muscular portion of the diaphragm The right crus is pierced by the right greater and
pulls the central tendon downward, thus increasing the lesser splanchnic nerves, and the left crus is pierced by
The sternal origin is by two fleshy slips from the back volume of the thoracic cavity and bringing about the left greater and lesser splanchnic nerves and the
of the xiphoid process. The costal origin is by fleshy slips inspiration. hemiazygos vein. The sympathetic trunks usually do
that interdigitate with the slips of origin of the trans- not pierce the diaphragm but pass behind the medial
versus abdominis muscle and arise from the inner sur- The diaphragmatic nerve supply is by way of the lumbocostal arches.
faces of the costal cartilages and adjacent parts of the right and left phrenic nerves, which are branches of the
last six ribs on each side. The lumbar portion of the right and left cervical plexuses and receive their fibers The base of the fibrous pericardial sac is partially
origin is by a right and a left crus and right and left primarily from the fourth cervical nerves, with some blended with the middle leaflet of the central tendon
medial and lateral lumbocostal arches (sometimes contribution from the third and fifth cervical nerves. of the diaphragm. The diaphragmatic portions of the
termed arcuate ligaments). The tendinous crura blend parietal pleura are closely blended with the upper sur-
with the anterior longitudinal ligament of the vertebral Several structures pass between the thoracic and faces of the right and left portions of the diaphragm.
column and are attached to the anterior surfaces of the abdominal cavities, mainly through apertures in the Where the diaphragmatic pleura reflects at a sharp
diaphragm. angle to become the costal pleura, the costodiaphrag-
matic recess or costophrenic sulcus is formed. Where
The aortic aperture is at the level of the twelfth tho- the costal pleura reflects to become pericardial pleura,
racic vertebra situated between the diaphragm and the the costomediastinal recess is formed.

12 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-11 Anatomy and Embryology

Thyroid cartilage Cricoid cartilage
Trachea
Thyroid gland Jugular (suprasternal) notch
Apex of lung
Cervical (cupula, or dome, of) parietal pleura Arch of aorta
Sternoclavicular joint Cardiac notch of left lung
Left border of heart
Clavicle
1st rib and costal cartilage

Right border of heart
Horizontal fissure
of right lung (often
incomplete)

1

TOPOGRAPHY OF THE LUNGS 2
(ANTERIOR VIEW) 3

Because the apex of each lung reaches as far superiorly Right nipple 4 Left nipple
as the vertebral end of the first rib, the lung usually 5
extends about 1 inch above the medial third of the Costo- 6 Costo-
clavicle when viewed from the front. Thus, the lung mediastinal diaphragmatic
projects into the base of the neck. recess of 7 recess of
pleural cavity 8 pleural cavity
The anterior border of the right lung descends 9
behind the sternoclavicular joint and almost reaches the Oblique fissure 10 Oblique fissure
midline at the level of the sternal angle. It continues of right lung of left lung
inferiorly posterior to the sternum to the level of Spleen
the sixth chondrosternal junction. There the inferior Costodiaphragmatic Inferior border of left lung
border curves laterally and slightly inferiorly, crossing recess of pleural cavity Left dome of diaphragm
the sixth rib in the midclavicular line and the eighth rib Pleural reflection
in the midaxillary line. It then runs posteriorly and Inferior border of right lung Stomach
medially at the level of the spinous process of the tenth Bare area of pericardium
thoracic vertebra. These levels are, of course, variable Pleural reflection Xiphoid process
and apply to the lung in expiration. In inspiration, the
levels for the inferior border are roughly two ribs lower. Gallbladder
Right dome of diaphragm
The anterior border of the left lung is similar in posi-
tion to that of the right lung. However, at the level of Liver
the fourth costal cartilage, it deviates laterally because
of the heart, causing a cardiac notch in this border of area—which, of course, varies in size with the phase of The diaphragm separates the liver from the right
the lung. The inferior border of the left lung is similar respiration—is called the costodiaphragmatic recess of the lung and, depending on the size of the liver, from the
in position to that of the right lung except that it pleura or the costophrenic sulcus. A similar but much less left lung. The left lung is also separated by the dia-
extends farther inferiorly because the right lung is extensive area is present where the anterior border of phragm from the stomach and the spleen.
pushed up by the liver below the diaphragm on the the lung does not extend to its limits medially—espe-
right side. cially in expiration—and the costal and mediastinal The nipple in males usually overlies the fourth inter-
parietal pleurae are in contact. This area is called the costal space in approximately the midclavicular line. In
The oblique fissure of the right lung, separating the costomediastinal recess. females, its position varies, depending on the size and
lower lobe from the upper and middle lobes, ends at functional state of the breast.
the lower border of the lung near the midclavicular
line. The horizontal fissure separating the middle from
the upper lobe begins at the oblique fissure and runs
horizontally forward to the lung’s anterior border,
which it reaches at about the level of the fourth
costal cartilage.

The oblique fissure of the left lung is similar in its
location to the corresponding fissure of the right side.
The left lung ordinarily has only two lobes, and there
is usually no horizontal fissure in this lung. Extra fis-
sures may occur in either lung, usually between bron-
chopulmonary segments and, in the left lung, between
the superior and inferior divisions of the upper lobe,
giving rise to a three-lobed left lung.

The lungs seldom extend as far inferiorly as the pari-
etal pleura, so some of the diaphragmatic parietal pleura
is usually in contact with costal parietal pleura. This

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 13

Plate 1-12 Respiratory System

Spinous process of T1 vertebra Cervical (cupula, or dome, of) parietal pleura
Apex of left lung
1st rib 1st rib

Oblique fissure of left lung Oblique fissure of right lung
Spine of scapula
Clavicle
Left border of costal
parietal pleura C Horizontal fissure
3 of right lung (often
1 4 incomplete)
2
3 5 Right border
4 of costal parietal
5
6 pleura

7
T
1

2

3

4

65

TOPOGRAPHY OF THE LUNGS 76
(POSTERIOR VIEW) 87

The apex of the lung extends as far superiorly as the 9 8
vertebral end of the first rib and therefore as high as 9
the first thoracic vertebra. From there, the lung extends 10 10
inferiorly as far as the diaphragm, with the base of the 11 Costo-
lung resting on the diaphragm and fitted to its superior 11
surface. Because of the diaphragm’s domed shape, the diaphragmatic
level of the highest point on the base of the right lung 12 12 recess
is about at the eighth to ninth thoracic vertebrae. The
highest point on the base of the left lung is a fraction Spleen of pleural
of an inch lower. From these high points, the bases of L cavity
the two lungs follow the curves of the diaphragm to Costodiaphragmatic 1
reach the levels described earlier for the inferior borders recess of pleural cavity
of the lungs. 2 Liver
Pleural reflection
The highest point on the oblique fissure of the two Inferior border of left lung Pleural reflection
lungs is on their posterior aspects, at about the level of Inferior border of right lung
the third to fourth thoracic vertebrae, a little over 1 inch Left kidney Right kidney
from the midline. Left dome of diaphragm Right dome of diaphragm
Right suprarenal gland
If the arm is raised over the head, the vertebral Left suprarenal gland
border of the scapula approximates the position of the
oblique fissure of the lung. If the shoulder is brought The diaphragm separates the base of the left lung limiting its expansion. A hepatic abscess may rupture
forward as far as possible, the scapula is carried laterally, from the fundus of the stomach and the spleen. Because through the diaphragm to involve the related pleural
so that the area in which auscultation can be satisfacto- of this relationship, if the stomach is distended by food cavity and lung.
rily carried out on the posterior aspect of the chest is or gas, it may push the diaphragm upward and embar-
significantly widened. rass respiratory activity. In this illustration, the lungs are shown in relation to
the bony thorax, scapula, and diaphragm, but overlying
The parietal pleura is separated from the visceral The diaphragm similarly separates the base of the the structures shown are the deep and superficial
pleura by a potential space (the pleural cavity), which right lung from the liver, which, if enlarged, elevates muscles of the back in addition to the superficial fascia
under normal circumstances contains only a minimal the diaphragm and pushes against the lung, possibly and skin.
amount of serous fluid. Caudal to the inferior margin
of the lung, the costal parietal pleura is in contact with
the diaphragmatic parietal pleura, forming the costo-
diaphragmatic recess (costophrenic sulcus). This allows
for the caudal movement of the inferior margin of the
lung on inspiration.

Under abnormal circumstances, the pleural cavity
may contain air, increased amounts of serous fluid,
blood, or pus. The accumulation of a significant amount
of any of these in the pleural cavity compresses the lung
and causes respiratory difficulties.

14 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-13 Anatomy and Embryology

Right lung

Groove for subclavian artery Apex
Area for trachea
Groove for brachiocephalic vein
Area for esophagus
Groove for 1st rib
Groove for azygos vein
Groove for superior vena cava
Pleura (cut edge)
MEDIAL SURFACE OF THE LUNGS Upper lobe
Area for thymus and fatty Oblique fissure
The medial (mediastinal) surfaces of the right and left tissue of anterior mediastinum
lungs present concave mirror images of the right and Right superior lobar
left sides of the mediastinum so that in addition to Anterior border (eparterial) bronchus
the structures forming the root of the lung, the medial Hilum
lung surface presents distinct impressions made by the Right pulmonary arteries
structures constituting the mediastinum (see Plates Horizontal fissure
1-18 and 1-19). Right bronchial artery
Cardiac impression
Right intermediate
Oblique fissure bronchus
Middle lobe
Right superior pulmonary
veins

Bronchopulmonary (hilar)
lymph nodes

Right inferior pulmonary
veins

Lower lobe

MEDIAL SURFACE OF THE RIGHT LUNG Groove for inferior vena cava Groove for esophagus

The oblique and horizontal fissures (if complete) divide Diaphragmatic surface Inferior border
the right lung into upper, middle, and lower lobes. The Pulmonary ligament
pleura reflects directly from the parietal to the visceral Groove for subclavian artery
surface around the root of the lung except where it Left lung Apex Groove for left brachiocephalic vein
forms the pulmonary ligament, which extends from the Area for trachea and esophagus
inferior aspect of the root vertically down to the medial Groove for arch of aorta Groove for 1st rib
border of the base of the lung. Oblique fissure
Anterior border
The main structures forming the root of the right Pleura (cut edge)
lung are the superior and inferior pulmonary veins, Area for thymus and fatty
which are situated anterior and inferior to the pulmo- Left pulmonary artery tissue of anterior
nary artery, and the bronchus, which is posterior in mediastinum
position. A number of lymph nodes are also present. Left bronchial arteries Upper lobe
Hilum
Much of the ventral and inferior portions of the Left main bronchus Cardiac impression
mediastinal surface show the impression caused by the Pulmonary ligament
heart. Superior to this is the groove caused by the supe- Left superior Cardiac notch
rior vena cava, with the groove for the right brachio- pulmonary veins Oblique fissure
cephalic (innominate) vein above that. Near the apex of
the lung is the groove for the right subclavian artery. Bronchopulmonary
Arching over the root of the lung is the groove caused (hilar) lymph nodes
by the azygos vein. Superior to this are the areas for the
trachea (anteriorly) and the esophagus (posteriorly). Lower lobe
The area for the esophagus continues inferiorly poste-
rior to the root of the lung. Left inferior
pulmonary vein
Because the inferior margin of the outer, costal
surface of the lung extends downward farther than the
lower margin of the medial surface, the diaphragmatic
surface of the lung can also be seen when the medial
aspect of the lung is observed.

MEDIAL SURFACE OF THE LEFT LUNG Inferior border Lingula
Groove for descending aorta Diaphragmatic surface Groove for esophagus
The oblique fissure (if complete) divides the left lung
into upper and lower lobes. The relationship of the Arching over the root of the left lung and continuing The portion of the medial surface of the left lung
pleura to the root of the left lung is similar to that on inferiorly—posterior to the root—to the base of the posterior to the areas for the descending aorta and
the right. lung is a groove for the aortic arch and the descending esophagus is in contact with the thoracic vertebral
aorta. bodies and the vertebral ends of the ribs except where
Structures forming the root of the left lung are the separated from them by structures lying in the position
pulmonary artery superiorly, the bronchus posteriorly, Superior to the groove for the aortic arch are, from described above.
and the superior and inferior pulmonary veins anteri- behind forward, areas for the esophagus and trachea,
orly and inferiorly. Some lymph nodes are also present. the groove for the left subclavian artery, the groove for As on the right side, the diaphragmatic surface of the
the left brachiocephalic (innominate) vein, and a groove left lung can be seen as the medial aspect of the lung is
A large impression caused by the heart is present caused by the first rib. observed.
anterior and inferior to the root of the lung. It is
responsible for a rather marked “cardiac notch” in the
anterior border of the upper lobe of the left lung. Infe-
rior to this notch is a projection of the upper lobe, the
lingula.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 15

Plate 1-14 Respiratory System

Apical (S1) Apical-posterior Superior
Upper lobe Anterior (S3) (S1 and S2) division

Posterior (S2) Anterior (S3) Upper lobe
Superior (S4)
Medial (S5) Lingular
Middle lobe Inferior (S5) division

Lateral (S4) Superior (S6)

Superior (S6) Anteromedial basal (S8) Lower lobe
Lower lobe Anterior basal (S8)
Lateral basal (S9)
Lateral basal (S9) Lateral view

Lateral view

Upper lobe Upper lobe Left lung
Bronchi (anterior view)
Bronchi
Right lung (anterior view) Middle lobe

Lower lobe

Lower lobe

Medial view Medial view
Apical-posterior
Upper lobe Apical (S1) (S1 and S2) Superior
Posterior (S2) division Upper lobe
Anterior (S3) Anterior (S3)

Middle lobe Medial (S5) Superior (S4) Lingular
Inferior (S5) division

Superior (S6) Superior (S6)

Posterior basal (S10) Posterior Lower lobe
Lower lobe Medial basal (S7) basal (S10)

Anterior basal (S8) Anteromedial
basal (S8)

Lateral basal (S9)

Lateral basal (S9)

BRONCHOPULMONARY SEGMENTS

A bronchopulmonary segment is that portion of the Right Upper Lobe Right Middle Lobe
lung supplied by the primary branch of a lobar bronchus.
Each segment is surrounded by connective tissue that The apical segment (S1) of the right upper lobe forms The middle lobe bronchus branches into two segmental
is continuous with visceral pleura and forms a separate, the apex of the right lung. It extends into the root bronchi, the complete branchings of which become
functionally independent respiratory unit. The artery of the neck as high as the vertebral end of the first rib. the lateral segment (S4) and medial segment (S5) of the
supplying a segment follows the segmental bronchus Toward the lateral aspect of the lung, the apical segment lobe. These segments are separated by a vertical plane
but the segmental veins are at the periphery of the dips downward slightly between the posterior and ante- extending from the hilum out to the costal surface of
segment and thus can be helpful in delineating it. rior segments. This boundary line is roughly at the level the lung and reaching its inferior border just anterior
of the first rib anteriorly and almost down to the second to the lower end of the oblique fissure. The segments
RIGHT LUNG rib posteriorly. are related to the anterior parts of the fourth and fifth
ribs and their costal cartilages.
The right main bronchus gives rise to three lobar The posterior segment (S2) extends from the apical
bronchi: upper, middle, and lower. Any two of these segment down to the lateral portion of the horizontal Right Lower Lobe
may occasionally have a common stem. fissure and the upper part of the oblique fissure.
The lower lobe bronchus gives off a posteriorly directed
The anterior segment (S3) extends from the apical superior segmental bronchus just below the level of
segment above down to the horizontal fissure at about the orifice of the middle lobe bronchus. The superior
the level of the fourth rib.

16 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-15 Anatomy and Embryology

Anterior view PULMONARY SEGMENTS IN RELATIONSHIP TO RIBS

Right lung Left lung

Superior lobe Apical (S1) 1 Superior lobe Superior Superior
Anterior (S3) 2 Apicoposterior (S1+S2) division lobe
Posterior (S2) 3 Anterior (S3) (culmen)

Superior lingular (S4) Lingular
Inferior lingular (S5) division

Middle lobe Lateral (S4)
Medial (S5)

Anterior basal (S8) 4 Anteromedial basal (S7+S8)
5
Medial basal (S7) 6 Posterior basal (S10) Inferior
Inferior lobe 7 lobe

Lateral basal (S9) Lateral basal (S9)

Posterior basal (S10)

Posterior view

Left lung 1 T Right lung
2 1
Superior Superior Apicoposterior (S1+S2) 3 2 Apical (S1) Superior
lobe division 4 3 Posterior (S2) lobe
(culmen) Anterior (S3) Anterior (S3)
5 4
Lingular Superior lingular (S4) 6
division 7 5
8
6 Lateral (S4) Middle
9 7 lobe
8
Inferior Superior (S6) 10 9 Superior (S6) Inferior
lobe Lateral basal (S9) 10 Lateral basal (S9) lobe
Posterior basal (S10) Posterior basal (S10)

BRONCHOPULMONARY SEGMENTS extra fissure; in this event, it has sometimes been called Unlike the situation on the right, the superior divi-
the cardiac lobe of the lung. sion of the left upper lobe has only two segments: the
(Continued) apicoposterior segment (S1 and S2), which corresponds
LEFT LUNG to a combination of the right apical and posterior seg-
segment (S6) of the lower lobe occupies the entire supe- ments, and the anterior segment (S3). The inferior or
rior part of the lower lobe and extends from the upper The left main bronchus is longer than the right and not lingular division also has two segments, the superior (S4)
part of the oblique fissure at about the level of the in such direct a line with the trachea. Foreign bodies, and inferior (S5) segments.
vertebral end of the third rib to the level of the vertebral therefore, are somewhat more likely to enter the right
end of the fifth or sixth rib. than the left bronchus. Left Lower Lobe

Inferior to the level at which the superior segmental Left Upper Lobe The segments here are similar to those of the right
bronchus arises, the lower lobe divides into four basal The upper lobe bronchus subdivides into a superior lower lobe except that the portion corresponding to the
segmental bronchi: medial (S7), anterior (S8), lateral division bronchus and an inferior or lingular division right anterior basal and medial basal segments is sup-
(S9), and posterior (S10). The basal segments of the bronchus. The superior division can be thought of as plied on the left by two bronchi that have a common
lower lobe form the base of the lung and rest on the corresponding to the right upper lobe, with the lingular stem and thus forms a single anteromedial basal (S8)
diaphragm. The medial basal segment is sometimes division corresponding to the right middle lobe; there segment. Other left lower lobe segments are superior
partially separated from other basal segments by an is usually no fissure separating the two, and their seg- (S6), lateral basal (S9), and posterior basal (S10).
mental subdivisions are not the same.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 17

Plate 1-16 Respiratory System

RELATIONSHIPS OF THE TRACHEA Cricoid cartilage Thyroid cartilage
AND MAIN BRONCHI
Thyroid gland Trachea
The trachea begins at the lower border of the larynx Right common carotid artery
(just below the cricoid cartilage) at about the level of Left common carotid artery
the sixth cervical vertebra and ends at about the level Right vagus nerve (X)
of the upper border of the fifth thoracic vertebra, where Anterior scalene muscle Left vagus nerve (X)
it divides into the two main bronchi. The thyroid gland
lies on the anterior and both lateral aspects of the Phrenic nerve Anterior scalene muscle
highest part of the trachea. Right internal jugular vein
Phrenic nerve (cut)
As the aorta arches over the root of the left lung, it External jugular vein
first lies anterior to the trachea and then on its left side. Brachial plexus Thoracic duct
The major arteries arising from the aortic arch are in
close relationship with the trachea. The brachiocephalic Right subclavian artery and vein Brachial plexus
(innominate) artery at first is anterior to the trachea and Left subclavian
then is on its right side before dividing into the right Brachiocephalic trunk artery and vein
common carotid and right subclavian arteries. The left
common carotid artery is first anterior to and then on Right brachiocephalic vein Left brachiocephalic vein
the left lateral aspect of the trachea. Phrenic nerve and
pericardiacophrenic Internal thoracic artery
The left brachiocephalic (innominate) vein crosses artery and vein (cut) Arch of aorta
from left to right, anterior to the trachea and partly
separated from it by the major branches of the aortic Superior vena cava Vagus nerve (X)
arch. The right brachiocephalic vein is separated from Right superior
the trachea by the right brachiocephalic artery. lobar (eparterial) Left recurrent
bronchus laryngeal nerve
The beginning of the right main bronchus lies ante-
rior to the esophagus. As it courses inferiorly and later- Right Ligamentum
ally to divide into the lobar bronchi, it is posterior to pulmonary arteriosum
the right pulmonary artery. The bronchus crosses in artery
front of the azygos vein and is separated from the tho- Pulmonary Left
racic duct by the esophagus. The relationship to other trunk pulmonary
structures at the root of the lung is shown in Plate 1-13. artery
Right
The beginning of the left main bronchus also lies pulmonary Left
anterior to the esophagus, from which it runs laterally veins pulmonary
and inferiorly to reach the hilum of the left lung. veins
Because its course is less vertical than that of the right Costal part Mediastinal
main bronchus (less in a direct line with the trachea), of parietal part of
foreign bodies are a little more likely to enter the right pleura parietal
bronchus than the left. (cut edge) pleura
(cut edge)
The left recurrent laryngeal nerve arises from the left Right costo-
vagus nerve as it crosses the arch of the aorta and swings diaphragmatic Costal part
posteriorly to loop around the aortic arch just lateral to recess of of parietal
the ligamentum arteriosum. This nerve then runs crani- pleural cavity pleura
ally in the groove between the trachea and the esopha- (cut edge)
gus to reach the larynx. Mediastinal part of
parietal pleura (cut edge) Phrenic Diaphragmatic
The esophagus starts as a continuation of the pharynx nerve part of
at the lower border of the larynx and continues through Diaphragmatic (cut) parietal pleura
the thorax. It then passes through the esophageal aper- part of parietal pleura and cut edge
ture of the diaphragm to enter the abdominal cavity and Right intermediate bronchus
terminate at the stomach. Left main bronchus
Phrenic nerve (cut)
The ligamentum arteriosum, the remnant of the Pericardium (cut edge)
ductus arteriosus, runs from the beginning of the left Azygos vein
pulmonary artery to the undersurface of the arch of the Diaphragm
Thoracic duct Esophagus and esophageal plexus
Inferior vena cava
trunks are formed, which pass through the esophageal
aorta. In fetal life, the ligamentum arteriosum shunts aperture of the diaphragm. The anterior trunk is mostly
blood from the pulmonary artery to the aorta, so that derived from the left vagus and the posterior trunk
fetal blood does not pass through the pulmonary mostly from the right vagus.
circulation.
Also worthy of note are the pulmonary veins, shown
The vagus nerves split into several bundles below the cut at the roots of the right and left lungs; the parietal
root of the lung and form the esophageal plexus on pleura, cut to expose the lungs, each of which is covered
the surface of the esophagus. Other contributions to by visceral pleura; the cut edge of the pericardium; and
the plexus come from the sympathetic trunks and the inferior vena cava passing through the diaphragm.
splanchnic nerves. At the lower end of the plexus, two

18 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-17 Anatomy and Embryology

Esophagus

Trachea (pulled
to left by hook)

3rd right posterior Superior left
intercostal artery bronchial
artery
Right bronchial artery

Right main bronchus Aorta
(pulled aside
Left main bronchus by hook)
(pulled to right by hook)
Inferior left
Esophageal artery bronchial artery

BRONCHIAL ARTERIES Esophageal branch
of bronchial artery

The lungs receive blood from two sets of arteries. The Variations in bronchial arteries Bronchial veins
pulmonary arteries follow the bronchi and ramify into Left main
capillary networks that surround the alveoli, allowing bronchus
exchange of oxygen and carbon dioxide. The bronchial (turned
arteries derive from the aorta. They supply oxygenated up by hook)
blood to the tissues of the lung that are not in close
proximity to inspired air, such as the muscular walls of Azygos
the larger pulmonary vessels and airways (to the level vein
of the respiratory bronchioles) and the visceral pleurae.
Right
The origin of the right bronchial artery is quite vari- bronchial
able. It arises frequently from the third right posterior vein
intercostal artery (the first right aortic intercostal
artery) and descends to reach the posterior aspects of Right and left bronchial Only single bronchial artery Right main Accessory
the right main bronchus. It may arise from a common arteries originating from to each bronchus (normally, bronchus hemiazygos
stem with the left inferior bronchial artery, which origi- aorta by single stem two to left bronchus) (pulled vein
nates from the descending aorta slightly inferior to the to left and
point where the left main bronchus crosses it. Or it may rotated Left bronchial vein
arise from the inferior aspect of the arch of the aorta by hook)
and course behind the trachea to reach the posterior
wall of the right main bronchus. bronchial artery on the left. Supernumerary bronchial these anastomoses are able to maintain full oxygenation
arteries may be present, going to either bronchus or of an involved area of lung has not been completely
On the left side, two arteries are typically present, both bronchi. established but would seem likely given the surprisingly
one superior and one inferior. The superior artery low rate of infarction in otherwise normal individuals
tends to arise from the inferior aspect of the aortic arch The majority of those who have studied the blood who experience pulmonary embolism.
as it becomes the descending aorta. The inferior artery supply of the lungs seem to agree that precapillary
most often arises near the beginning of the descending anastomoses are present between the bronchial and pul- Branches of the bronchial arteries spread out on the
aorta toward its posterior aspect. The left bronchial monary arteries, which can enlarge when either of these surface of the lung beneath the pleura where they
arteries come to lie on the posterior surface of the left two systems becomes obstructed (an event that more form a capillary network that contributes to the pleural
main bronchus and follow the branching of the bron- commonly affects the pulmonary arteries). Whether blood supply.
chial tree into the left lung.

Some of the more common variations of the bron-
chial arteries are shown in the lower part of the illustra-
tion. The right bronchial artery and the inferior left
bronchial artery may come from a common stem arising
from the descending aorta. There may be only a single

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 19

Plate 1-18 Respiratory System

Right lateral view

MEDIASTINUM Cervical (cupula, or dome, of) parietal pleura Brachial Anterior scalene muscle and phrenic nerve
and suprapleural membrane (Sibson fascia) plexus
The mediastinum is that portion of the thorax that lies Right subclavian artery and vein
between the right and left pleural sacs and is bounded 1st rib
ventrally by the sternum and dorsally by the bodies of Trachea Clavicle
the thoracic vertebrae. The superior boundary of the
mediastinum is defined by the thoracic inlet, and its Right vagus nerve (X) Subclavius muscle
inferior boundary is formed by the diaphragm. By con-
vention, the mediastinum is divided into superior and Esophagus 1st rib
inferior parts by a plane extending horizontally from the
base of the fourth vertebral body to the angle of the Sympathetic trunk Right and left
sternum. The superior mediastinum contains the aortic brachiocephalic veins
arch; the brachiocephalic (innominate) artery; the Right superior
beginnings of the left common carotid and left subcla- intercostal vein Right internal
vian arteries; the right pulmonary artery trunk; the thoracic artery
right and left brachiocephalic (innominate) veins as 4th thoracic
they come together to form the superior vena cava; the vertebral body Thymus (seen through
trachea with right and left vagus, cardiac, phrenic, and mediastinal pleura)
left recurrent laryngeal nerves; the esophagus and the Arch of azygos vein
thoracic duct; most of the thymus; the superficial part Superior vena cava
of the cardiac plexus; and a few lymph nodes. Right main
bronchus and Phrenic nerve and
The anterior mediastinum lies below the superior bronchial artery pericardiacophrenic
mediastinum in the area bordered by the pericardium artery and vein*
posteriorly and the body of the sternum anteriorly. The Azygos vein
anterior mediastinum contains a small amount of fascia, Right pulmonary
the sternopericardial ligaments, a few lymph nodes, and Posterior artery
variable amounts of the thymus. intercostal vein
and artery and Mediastinal
The middle mediastinum contains the heart and peri- intercostal nerve part of parietal
cardium, the beginning of the ascending aorta, the pleura (cut edge)
lower half of the superior vena cava with the azygos vein Internal
opening into it, the bifurcation of the trachea into right intercostal Fibrous
and left bronchi, the pulmonary artery dividing into muscle pericardium
right and left branches, the terminal parts of the right over right atrium
and left pulmonary veins, and the right and left phrenic Internal intercostal
nerves. membrane deep to Right
external intercostal pulmonary
The posterior mediastinum is bordered anteriorly muscle veins
by the tracheal bifurcation and posteriorly by the
vertebral column. The posterior mediastinum contains Gray and white Inferior vena
the thoracic portion of the descending aorta, esopha- rami communicantes cava (covered by
gus, azygos and hemiazygos veins, right and left vagus mediastinal part
nerves, splanchnic nerves, thoracic duct, and many Costal part of parietal of parietal pleura)
lymph nodes. pleura (cut edge)
Diaphragm
The relationships among compartments and their Greater thoracic splanchnic nerve (covered by
included structures are of great clinical importance Esophagus and esophageal plexus diaphragmatic
because a space-occupying lesion in any one of these Bronchopulmonary (hilar) lymph nodes part of parietal
may affect neighboring structures. These relationships pleura)
can be appreciated through careful scrutiny of Plates Pulmonary ligament (cut)
1-18 and 1-19. *Nerve and vessels commonly run independently Costal part of
parietal pleura
The esophagus passes through the posterior medi- (cut edge)
astinum immediately ventral to the thoracic vertebral Costodiaphragmatic
bodies and is separated from these by the right inter- recess of pleural cavity
costal arteries, thoracic duct, and hemiazygos vein. It
partially overlaps the azygos vein to its right side. The RIGHT THORACIC CAVITY superior intercostal vein, which accepts blood from the
right and left vagus nerves form a plexus around the upper three or four intercostal spaces.
esophagus, with the left vagus trunk on its anterior The hilum of the right lung contains the right main
surface and the right vagus trunk on its posterior bronchus with the right pulmonary artery trunk ante- The visceral pleurae reflect onto the parietal medias-
surface. The trachea passes through the superior medi- rior and the right pulmonary veins anteriorly and infe- tinal surface immediately below the hilum of the right
astinum anterior to the esophagus. This relationship riorly. The azygos vein arches over the root of the right lung to form the pulmonary ligament.
continues as the trachea passes into the middle medi- lung at the hilum to empty into the superior vena cava.
astinum to bifurcate. As the azygos vein begins to arch, it receives the right The thoracic portion of the right ganglionated sym-
pathetic trunk courses vertically near the necks of the
In the superior and anterior mediastinum, the rem- ribs and is connected with each intercostal nerve by a
nants of the thymus gland are present in adults. The
right and left brachiocephalic veins and the superior
vena cava are the most anterior of the major structures
in the mediastinum followed in sequence (from anterior
to posterior) by the aortic arch, the brachiocephalic
artery, and the beginnings of the left common carotid
and left subclavian arteries.

20 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-19 Anatomy and Embryology

Left lateral view Cervical (cupula, or dome, of) parietal pleura
Anterior scalene muscle and phrenic nerve and suprapleural membrane (Sibson fascia)

Brachial plexus 1st rib

Esophagus

Left subclavian vein and artery Left vagus nerve (X)

Subclavius muscle Thoracic duct
Clavicle
Left superior
Left brachiocephalic vein intercostal vein
Arch of aorta

MEDIASTINUM (Continued) Left internal thoracic artery Left recurrent
laryngeal nerve
gray and a white ramus communicans. The splanchnic Thymus (seen through
nerves branch from the fifth (or sixth) to the twelfth mediastinal pleura) Bronchopulmonary
ganglia and course medially and inferiorly to pierce the (hilar) lymph nodes
crus of the diaphragm and enter the abdominal cavity. Ligamentum arteriosum
Accessory
The right phrenic nerve and the pericardiacophrenic Left pulmonary artery hemiazygos vein
artery and vein pass vertically between the mediastinal
parietal pleura and the pericardial sac to supply the Left phrenic Posterior
diaphragm. nerve and intercostal vein
pericardiacophrenic and artery and
The medial “wall” of the right thoracic cavity is artery and vein* intercostal nerve
formed by the thoracic vertebral bodies posteriorly and
anteriorly by the mediastinum, dominated by the peri- Mediastinal part Internal
cardial sac containing the heart. The posterior, lateral, of parietal pleura intercostal
and anterior walls of the right thoracic cavity comprise (cut edge) muscle
the thoracic cage, which is limited inferiorly by the
diaphragm. Fibrous Internal
pericardium intercostal
LEFT THORACIC CAVITY membrane
Left deep to
The structures forming the hilum of the left lung are pulmonary external
the left main bronchus, left pulmonary artery, and left veins intercostal
pulmonary veins. The pulmonary artery is located muscle
superior to the left main bronchus with the left pulmo- Fat pad Gray and white
nary veins posterior and inferior. rami com-
Pulmonary municantes
The aorta arches over and descends posterior to the ligament (cut)
left hilum. As it descends, it lies at first to the left of the Costal pleura
thoracic vertebral bodies (starting with the lower border Esophagus and (cut edge)
of the fourth vertebra); it then approaches the anterior esophageal plexus
aspect of the vertebral bodies, where it lies as it pierces (covered by Sympathetic trunk
the diaphragm. The aorta gives off nine pairs of inter- mediastinal part
costal arteries. They supply the lower nine intercostal of parietal pleura) Greater thoracic
spaces. splanchnic nerve
Costodiaphragmatic
The ligamentum arteriosum (the remnant of the recess of pleural cavity Thoracic (descending) aorta
embryonic ductus arteriosus) runs between the left pul-
monary artery and the aortic arch. Costal part of parietal pleura (cut edge) Left main bronchus and bronchial artery

The thoracic portion of the left ganglionated sympa- Diaphragm (covered by diaphragmatic part of parietal pleura)
thetic trunk is similar to the portion on the right side
and does not need special description here. *Nerve and vessels commonly run independently

The left phrenic nerve and the left pericardiaco- under the arch to course upward to the larynx. The into the left brachiocephalic vein, often anastomosing
phrenic artery and vein cross the aortic arch and vagus nerve continues caudally on the posterior aspect with the accessory hemiazygos vein.
descend between the mediastinal parietal pleura and the of the root of the lung to enter the esophageal plexus,
pericardial sac to pass through the muscular part of the from which the left vagal trunk emerges to follow the The medial wall of the left thoracic cavity is formed
diaphragm. esophagus into the abdomen. by the thoracic vertebral bodies posteriorly and the
mediastinum containing the pericardial sac and the
The left vagus nerve passes in front of the arch at the The left superior intercostal vein typically drains heart. As with the right thoracic cavity, the posterior,
aorta, giving off its recurrent branch, which passes blood from the upper three or four intercostal spaces. lateral, and anterior walls of the left thoracic cavity are
It crosses the aortic arch and the beginnings of the left formed by the thoracic cage and limited inferiorly by
subclavian and left common carotid arteries and empties the diaphragm.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 21

Plate 1-20 Respiratory System

INNERVATION OF TRACHEOBRONCHIAL TREE: SCHEMA

INNERVATION OF THE LUNGS From hypothalamic
AND TRACHEOBRONCHIAL TREE and higher centers

The tracheobronchial tree and lungs are innervated by Glossopharyngeal nerve (IX) Afferent nerves
the autonomic nervous system. Three types of pathways from nose and
are involved: autonomic afferent, parasympathetic efferent, Vagus nerve (X) (cholinergic; sinuses (via
and sympathetic efferent. Each type of fiber is discussed efferent to smooth muscle trigeminal [V] and
here; the neurochemical control of respiration is and glands; afferent from glossopharyngeal [IX]
covered later in the section on physiology (see Plates aorta, tracheobronchial nerves) may also
2-25 and 2-26). mucosa, and alveoli) initiate reflexes
in airways

Superior cervical
sympathetic
ganglion

AUTONOMIC AFFERENT FIBERS Descending tracts Superior laryngeal nerve
in spinal cord Larynx
Afferent fibers from stretch receptors in the alveoli and
from irritant receptors in the airways travel via the Thoracic T1 Sympathetic
pulmonary plexus (located around the tracheal bifurca- spinal T2 nerves
tion and hila of the lungs) to the vagus nerve. Similarly, cord (adrenergic)
fibers from irritant receptors in the trachea and from T3 Carotid sinus
cough receptors in the larynx reach the central nervous Left Cough
system via the vagus nerve. Chemoreceptors in the T4 Carotid body recurrent receptors
carotid and aortic bodies and pressor receptors in the laryngeal
carotid sinus and aortic arch also give rise to afferent T5 Common nerve
autonomic fibers. Whereas the fibers from the carotid carotid
sinus and carotid body travel via the glossopharyngeal artery
nerve, those from the aortic body and aortic arch travel
via the vagus nerve. Other receptors in the nose and Arch of
nasal sinuses give rise to afferent fibers that form parts aorta
of the trigeminal and glossopharyngeal nerves. In addi-
tion, the respiratory centers are controlled to some Sympathetic trunk Pulmonary plexus
extent by impulses from the hypothalamus and higher
centers as well as from the reticular activating system. Parasympathetic fibers Cough receptors
Sympathetic fibers Irritant receptors
PARASYMPATHETIC EFFERENT FIBERS Afferent fibers

All parasympathetic preganglionic efferent fibers to the Stretch receptors (Hering-Breuer reflex)
tracheobronchial tree are contained in the vagus nerve,
originating chiefly from cells in the dorsal vagal nuclei into β1, located in the heart, and β2, located in smooth Certain tissues contain both α and β receptors. The
that are closely related to the medullary respiratory muscle throughout the body, including bronchial and result of stimulation depends on the nature of the stim-
centers. The fibers relay with short postganglionic vascular smooth muscle. Generally, α stimulation is ulating catecholamine and the relative proportion of
fibers in the vicinity of (or within the walls of) the excitatory. β Stimulation may be inhibitory (relaxation the two types of receptors. In the lungs, β2 stimulation
tracheobronchial tree. This parasympathetic efferent of bronchial smooth muscle) or excitatory (increase in (there are no β1 receptors there) cause bronchodilata-
pathway carries motor impulses to the smooth muscle both heart rate and force of contraction). β Stimulation tion and possibly decreased secretion of mucus; α-
and glands of the tracheobronchial tree. The impulses also tends to mobilize energy by glycogenolysis and adrenergic stimulation by pharmacologic agents causes
are cholinergically mediated and produce bronchial lipolysis. bronchoconstriction.
smooth muscle contraction, glandular secretion, and
vasodilatation.

SYMPATHETIC EFFERENT FIBERS

The preganglionic efferent fibers emerge from the
spinal medulla (cord) at levels T1 or T2 to T5 or T6
and pass to the sympathetic trunks via white rami com-
municantes. Fibers carrying impulses to the larynx and
upper trachea ascend in the sympathetic trunk and
synapse in the cervical sympathetic ganglia with post-
ganglionic fibers to those structures. The remainder
synapse in the upper thoracic ganglia of the sympathetic
trunks, from where the postganglionic fibers pass to the
lower trachea, bronchi, and bronchioles, largely via the
pulmonary plexus. The postganglionic nerve endings
are adrenergic. Sympathetic stimulation relaxes bron-
chial and bronchiolar smooth muscle, inhibits glandular
secretion, and causes vasoconstriction. Pharmacologic
studies indicate that there are two types of adrenergic
receptors, α and β. The α receptors are located prima-
rily in smooth muscle and exocrine glands. The β
receptors have been differentiated pharmacologically

22 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-21 Anatomy and Embryology

STRUCTURE OF THE TRACHEA Median cricothyroid ligament Connective tissue sheath
AND MAJOR BRONCHI Thyroid cartilage (visceral layer of pretracheal fascia)
Cricoid cartilage
Tracheal cartilage (ring)
Elastic fibers
Gland
Small artery
Lymph vessels
Nerve
Epithelium

Anterior wall

The trachea or windpipe passes from the larynx to the Connective tissue sheath Cross section
level of the upper border of the fifth thoracic vertebra, (visceral layer of pretracheal through trachea
where it divides into the two main bronchi that enter fascia) (partially
the right and left lungs. About 20 C-shaped plates of cut away below) Posterior wall
cartilage support the anterior and lateral walls of the
trachea and main bronchi. The posterior wall, or mem- Annular (intercartilaginous) Nerve Trachealis
branous trachea, is free of cartilage but does have inter- ligaments Small arteries (smooth) muscle
lacing bundles of muscle fibers that insert into the
posterior ends of the cartilage plates. The external Tracheal cartilages Gland Esophageal muscle
diameter of the trachea is approximately 2.0 cm in men Elastic fibers
and 1.5 cm in women. The tracheal length is approxi- Mucosa of posterior tracheal Epithelium
mately 10 to 11 cm. wall shows longitudinal folds
formed by dense collections Lymph vessels
Mucous glands are particularly numerous in the pos- of elastic fibers
terior aspect of the tracheal mucosa. Throughout the
trachea and large airways, some of these glands lie Superior lobar
between the cartilage plates, and others are external to (eparterial) bronchus
the muscle layers with ducts that penetrate this layer
to open on the mucosal surface. Posteriorly, elastic B1 Superior lobar
fibers are grouped in longitudinal bundles immediately bronchus
beneath the basement membrane of the tracheal epi- To
thelium, and these appear to the naked eye as broad,
flat bands that give a rigid effect to the inner lining of upper B2 B1+2
the trachea; they are not so obvious anteriorly. More lobe
distally, the bands of elastic fibers are thinner and sur- B3
round the entire circumference of the airways. B3 Superior To
division bronchus upper
Just above the point at which the main bronchus Middle Lingular bronchus lobe
enters the lung, the cartilage plates come together to lobar bronchus
completely encircle the airway. Posteriorly, the ends of Right and left B4 To
the plates meet, and the membranous region disap- To B4 main bronchi lingula
pears. The plates are no longer C-shaped but are middle Intermediate bronchus
smaller, more irregular, and arranged around the entire B5
bronchial wall. At the hilum of the lung, the main bron- lobe B5 Inferior lobar bronchus
chus divides into lobar bronchi, at which point the B6
plates of cartilage are larger and saddle shaped to Inferior lobar bronchus B8
support this region of branching.
To B6 To lower lobe
At the level where cartilage completely surrounds the lower B7
circumference of the airway, the muscle coat undergoes lobe B10 B9
a striking rearrangement. It no longer inserts into the B8 B9 B10
cartilage (as in the trachea) but forms a separate layer
of interlacing bundles internal to it. From this point and Intrapulmonary Extrapulmonary Intrapulmonary
more distally, the airways can now be completely
occluded by contraction of the muscle; however, the
trachea is never subjected to such complete sphincteric
action. The right main bronchus is shorter and less
sharply angled away from the trachea than the left. For
this reason, foreign bodies may lodge in the right main
bronchus more often than the left when aspiration takes
place while sitting or standing.

LOBES AND SEGMENTS there are eight bronchopulmonary segments in the left only about 50% of subjects, even a lobe is not always
lung but 10 in the right lung (see Plate 1-14). A segment an end unit.
The right lung has three lobes and the left has two, is not a functional end unit in the lung because it is not
although the lingula of the left lung is analogous to the isolated by connective tissue. Neighboring segments For counting orders or generations of airways, it is
right middle lobe. share common venous and lymphatic drainage and, sometimes appropriate to count the trachea as the first
by collateral ventilation, air passes across segmental generation, the main bronchi as the second generation,
The bronchopulmonary segments are the topo- boundaries. The pleura isolates one lobe from another, and so on. To compare features within a segment, it is
graphic units of the lung and are a means of identifying but because the main or oblique fissure is complete in better to count the segmental bronchi as the first gen-
regions of the lung either radiologically or surgically; eration of airways.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 23

Plate 1-22 Respiratory System

Subdivisions of intrapulmonary airways Structure of intrapulmonary airways

Segmental Terminal bronchiole Smooth muscle
bronchus Elastic fibers
Alveolus

Cartilages

Large 1st order Respiratory
intrasegmental 2nd order bronchioles
bronchi (about 3rd order (alveoli appear
5 generations) at this level)

Bronchi

Small intrasegmental Cartilage plates become Alveolar ducts
bronchi (about sparser but persist at Alveolar sac
15 generations) points of branching Alveoli

No further cartilage Acinus (part of lung
plates supplied by terminal
bronchiole)

Bronchioles Terminal
bronchiole
Acinus
Respiratory
Lobule bronchioles

(3–8 orders)

Alveolar sacs
and alveoli

Opening of alveolar duct

Pores of Kohn

INTRAPULMONARY AIRWAYS large bronchi have submucosal mucous glands within None of these units is isolated from its neighbor by
their walls. complete connective tissue septa. Collateral air passage
According to the distribution of cartilage, airways are occurs between acinus and acinus and between lobule
divided into bronchi and bronchioles. Bronchi have When any airway is pursued to its distal limit, the and lobule through the pores of Kohn in the alveolar
cartilage plates as discussed earlier. Bronchioles are distal terminal bronchiole is reached. Three to five terminal wall and through respiratory bronchioles between adja-
to the bronchi beyond the last plate of cartilage and bronchioles make up a lobule. The acinus, or respiratory cent alveoli.
proximal to the alveolar region. Cartilage plates unit, of the lung is defined as the lung tissue supplied
become sparser toward the periphery of the lung, and by a terminal bronchiole. Acini vary in size and shape. Connective tissue forms a sheath around airways and
in the last generations of bronchi, plates are found In adults, the acinus may be up to 1 cm in diameter. blood vessels. It also forms septa that are relatively
only at the points of branching. The large bronchi Within the acinus, three to eight generations of respira- numerous in some parts of the edges of the lingula and
have enough inherent rigidity to sustain patency even tory bronchioles may be found. Respiratory bronchioles middle lobe and parts of the costodiaphragmatic and
during massive lung collapse; the small bronchi collapse have the structure of bronchioles in part of their walls costovertebral edges. These septa impede collateral
along with the bronchioles and alveoli. Small and but have alveoli opening directly to their lumina as well. ventilation but do not prevent collateral air drift because
Beyond these lie the alveolar ducts and alveolar sacs they never completely isolate one unit from its neigh-
before the alveoli proper are reached. bor in humans.

24 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-23 Anatomy and Embryology

STRUCTURE OF BRONCHI AND Higher magnification Section of large bronchus
BRONCHIOLES—LIGHT of epithelium Ciliated columnar epithelium
MICROSCOPY with many goblet cells
Section of medium-sized bronchus Basal cells
The airways are the hollow tubes that conduct air to Ciliated columnar epithelium Basement membrane
the respiratory regions of the lung. They are lined with many goblet cells Smooth muscle
throughout their length by pseudostratified, ciliated, Arterioles Mucous glands
columnar epithelium (also referred to as respiratory epi- Smooth muscle Stroma with many elastic fibers
thelium) supported by a basement membrane (see Plate Mucous glands Artery
1-24 for details of cell types and their arrangement). Nerve fiber Nerve fiber
The remainder of the wall includes a muscle coat and Perichondrium
accessory structures such as submucosal glands, together Stroma with elastic fibers Cartilage
with connective tissue. In the bronchi, cartilage pro- Alveolus Fibroelastic layer
vides additional support. Cartilage
3 mm
In adults, the diameter of the main bronchus is Section of bronchiole
similar to that of the trachea (∼2 cm), and the diameter
of a terminal bronchiole is about 1 mm. These meas- m1m.5 Ciliated, cuboidal epithelium with a few goblet cells;
urements vary with age and the size of the individual smooth muscle ring with nerve fibers and blood vessels;
and with the functional state of the airway. For refer- stroma contains many elastic fibers. Cartilage plates
ence purposes, it is helpful to designate airways by their and glands absent.
order or generation along an axial pathway. The epi-
thelium is thicker in the larger airways and gradually
thins toward the periphery of the lung.

Immediately beneath the basement membrane,
elastic fibers are collected into fine bands that form
longitudinal ridges. In cross-section, the fiber bundles
are at the apices of the bronchial folds. The rest of the
wall is made up of loose connective tissue containing
blood vessels, nerves, capillaries, and lymphatics.

BLOOD SUPPLY

The bronchial arteries supply the capillary bed in the
airway wall, forming one plexus internal and another
external to the muscle layer (see also Plate 1-26).

VENOUS DRAINAGE muscle layer. Lymphatics are numerous in airway walls. nerve endings that are almost certainly sensory fibers
They are not found in alveolar walls but start in the have also been described, but whether there are also
The capillary bed of the bronchi and bronchioles drains region of the respiratory and terminal bronchioles. motor nerve endings at the epithelial level is uncertain.
into the pulmonary veins. At each point of airway bifur-
cation, two venous tributaries join. Only at the hilum NERVE SUPPLY As the lumen tapers toward the periphery and the
is there some drainage to the azygos system through airway wall becomes thinner, the small airways are
veins referred to as the true bronchial veins. Large nerves—both myelinated and nonmyelinated— more intimately related to the surrounding alveoli.
are seen in the wall of the airway. Motor nerves supply Functional interaction between the two is probably very
LYMPHATICS the glands and the muscles of the airway. Intraepithelial important at this level, and inflammation spreads easily
through the walls of the small airways.
Lymphatic channels lie internal to and between the
plates of cartilage and internal and external to the

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 25

Plate 1-24 Respiratory System

Electron micrograph of Goblet cell
bronchial epithelium Ciliated columnar
cell
ULTRASTRUCTURE OF THE
TRACHEAL, BRONCHIAL, AND Basal cell
BRONCHIOLAR EPITHELIUM Basement membrane

The lining of the respiratory airways is predominantly Light micrograph
a pseudostratified, ciliated, columnar epithelium in of respiratory
which all cells are attached to the basement membrane epithelium
but not all reach the lumen. In the smaller peripheral
airways, the epithelium may be only a single layer thick Microtubule B
and cuboidal rather than columnar because basal cells
are absent at this level. Microtubule A Shaft of cilium
Axial filament complex
Ciliated cells are present in even the smallest airways Microtubule
and respiratory bronchioles, where they are adjacent to doublet (9 total)
alveolar lining cells. The “ciliary escalator” starts at the
most distal point of the airway epithelium. In smaller Cell membrane
airways, the cilia are not as tall as in the more central
airways. Eight epithelial cell types can be identified in Mucus Trachea and large bronchi.
humans, although ultrastructural features and cell Ciliated and goblet cells
kinetics have been studied mainly in animals. The fol- Nerve predominant, with some
lowing classification is based on studies in the rat: the Ciliated serous cells and occasional
(1) basal and (2) pulmonary neuroendocrine cells are cells brush cells and Clara cells.
attached to the basement membrane but do not reach Numerous basal cells
the lumen; (3) the intermediate cell is probably the Goblet and occasional Kulchitsky
precursor that differentiates into (4) the ciliated cell, (mucous) cells are present.
(5) the brush cell, or one of the secretory cells—(6) cell
the mucous (goblet) cell, (7) the serous cell, or (8) the Serous cell
Clara cell. Basement
membrane Pulmonary neuroendocrine
The basal cell divides and daughter cells pass to the cell (PNEC) (Kulchitsky cell)
superficial layer.
Basal Brush Basal Nerve
The pulmonary neuroendocrine cell (PNEC), previ- cell cell cell Goblet cell (discharging)
ously referred to as the Kulchitsky cell, contains numer-
ous neurosecretory granules and is a rare, but likely Nerves Clara cell
important, functional cell of the airway epithelium. The
PNEC neurosecretory granules contain serotonin and Ciliated cells Cross
other bioactive peptides such as gastrin-releasing Basal cell section
peptide (GRP). PNECs are more numerous before
birth and may play a role in the innate immune system. Clara cell Magnified
Basement membrane detail of cilium
The intermediate cell is columnar. It has electron-
lucent cytoplasm and no special features. It is probably Bronchioles. Ciliated cells dominant and Clara cells Electron micrograph of cilia
the cell that differentiates into the others. progressively increase distally along airways. Goblet
cells and serous cells decrease distally and are absent
The ciliated cell carries the cilia of the respiratory in terminal bronchioles.
epithelium. The cilium has nine double pairs of
axonemes and a special axoneme in the center. The cytoplasm is electron lucent, and there is relatively The basement membrane is well defined and becomes
arrangement is modified at the base and at the apex, more smooth than rough endoplasmic reticulum. thinner in small airways. In certain diseases—notably
where a coronet of small claws has been identified. The asthma—the reticular basement membrane (lamina
feet of the axonemes are arranged so that a cilium The serous cell is mainly found centrally; the Clara reticularis) increases in thickness, although its structure
“plugs” into the cytoplasm. The axonemes are attached cell is found only distally. These are the more common remains normal.
to each other by “arms” of dynein, a contractile protein, secretory cells of the airways, but irritation, drug reac-
and these provide the mechanism for ciliary motion. tion, or infection may lead to an increase in the number Nerve fibers are seen within the epithelium. They
of secretory cells. The serous and Clara cells then are nonmyelinated and without a Schwann cell sheath.
The brush cell resembles a similar cell type found in develop into mucous cells. Differentiated cells are seen Their vesicle content suggests that the fibers are
the gut and in the nasal sinuses. Its function in the in mitosis, but this is probably not the main way that sensory or motor and either cholinergic or adrenergic
respiratory tract remains unknown, but hypotheses cell numbers increase. in type.
regarding its function include immune surveillance, cell
regeneration, chemoreceptor, sensor of alveolar fluid or
air tension, and regulator of capillary resistance and
perfusion.

The mucous (goblet) cell is a secretory cell containing
numerous large and confluent secretory granules. Elec-
tron microscopic studies have shown that confluence
represents fusion of the two trilaminar membranes of
adjacent granules to produce a pentilaminar layer.

The serous cell resembles the serous cell of the sub-
mucosal gland and contains small, discrete, electron-
dense secretory granules. Its cytoplasm is also more
electron dense than that of the Clara cell.

The Clara cell also contains small, discrete, electron-
dense granules, but compared with the serous cell, the

26 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-25 Anatomy and Embryology

Bronchial lumen
1. Ciliated duct

BRONCHIAL SUBMUCOSAL 2. Collecting duct
GLANDS

The submucosal glands of the human airways are of the 3. Mucous tubules 4. Serous tubules
branched tubuloacinar type: tubulo refers to the main
part of the secretory tubule and acinar to the blind end M ϭ myoepithelial cell
of such a tubule. BM ϭ basement membrane
N ϭ nerve
Three-dimensional reconstruction of the gland
reveals its various zones: M BM MN BM M N BM

1. The origin is referred to as the ciliated duct and is Tall cells packed Electron-lucent granules Branch from and at ends
lined by bronchial epithelium with its mixed pop- with mitochondria
ulation of cells. With the naked eye, the origin of within cells and in of mucous tubules. Small,
the gland is seen as a hole of pinpoint size in the
surface epithelium of the bronchus. lumen discrete electron-dense

2. The second part of the duct expands to form the granules
collecting duct and is lined by a columnar epithe-
lium in which the cells are eosinophilic after stain- Submucosal glands
ing with hematoxylin and eosin. Ultrastructural
examination shows these cells to be packed with Cartilage
mitochondria, resembling the cells of the striated
duct of the salivary gland (except that they lack Light micrograph of submucosal glands
the folds of membrane responsible for the appear-
ance of striation). The collecting duct may be up than one-third the thickness of the airway wall (meas- In humans, the secretory tubules of the mucous and
to 0.25 mm in diameter and 1 mm long. It passes ured from the luminal surface to the cartilage layer). serous cells contain mainly an acid glycoprotein, either
obliquely from the airway lumen, so the usual This ratio is similar in both children and adults and is sialic acid or its sulfate ester.
macroscopic section does not include the full consistent throughout airways at various levels of
length of the duct. It is usually seen as a rather branching. The ratio of gland size to wall thickness The concentration of bronchial submucosal openings
large “acinus” composed of cells without secretory (sometimes referred to as the Reid index) is a useful way in the trachea is on the order of one gland opening per
granules. of assessing abnormalities in gland size because gland mm2. The glands become sparser towards the periphery
hypertrophy is a hallmark of a number of inflammatory of the lung, their decrease in number and concentration
3. About 13 tubules rise from each collecting duct. diseases of the large airways. being parallel to the diminution in the amount of car-
These may branch several times and are closely tilage in the airway.
intertwined with each other. The secretory cells
lining these tubules are of two types: mucous and
serous. Mucous cells line the central or proximal
part of a tubule; serous cells line the distal part.
Outpouchings or short-sided tubules may arise
from the sides of the mucous tubules, and these
are lined by serous cells. The peripheral portion
of a tubule usually branches several times, and
each of the final blind endings is lined with serous
cells.

The gland tissue is internal to a basement membrane.
In addition to the cell types described above, the fol-
lowing are found: (1) myoepithelial cells; (2) “clear”
cells; and (3) nerve fibers, including motor fibers.
Outside the basement membrane, there are rich vascu-
lar and lymphatic networks and the nerve plexus.

In histologic cross-sections, the submucosal gland is
seen as a compact structure. In a main bronchus of an
adult, the gland is about 0.2 mm in diameter or less

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 27

Plate 1-26 Terminal bronchiole Respiratory System

Pulmonary Bronchial artery (from left heart Pulmonary vein (to left heart)
artery (from via thoracic aorta)
right heart)
Respiratory
Pulmonary bronchioles
vein (to
left heart) Capillary plexuses
within alveolar
wall

Septum Capillary bed
within alveolar wall
(cut away in places)

Septum

Visceral pleura
and subpleural
capillaries

Pulmonary arteries and their branches distribute segmentally with the bronchi. Pulmonary veins and their tributaries drain intersegmentally.

INTRAPULMONARY BLOOD ARTERIES acinus, lobule, or segment. Veins receive tributaries
CIRCULATION from the alveolar capillary network, the pleura, and the
The bronchial arteries arise from the aorta and supply airways.
The human lung is supplied by two arterial systems the capillary plexus of the airway walls from the hilum
referred to as pulmonary and bronchial, each originating to the respiratory bronchiole. PRECAPILLARY ANASTOMOSIS
from a different side of the heart. Blood from the
lungs is drained by two venous systems, pulmonary The pulmonary artery branches run with airways and Pulmonary and bronchial arteries, and hence the right
and true bronchial. The pulmonary veins drain oxygen- their accompanying bronchial arteries in a single con- and left sides of the heart, communicate through
ated blood from the regions supplied by the pulmonary nective tissue sheath referred to as the bronchoarterial or the capillary bed in the region of the respiratory bron-
artery and deoxygenated blood from the airways within bronchovascular bundle. The pulmonary artery trans- chiole and through the intrapulmonary venous bed.
the lung that are supplied by the bronchial artery. forms into a capillary bed only when it reaches the Pulmonary-to-bronchial artery anastomoses are present
The true bronchial veins serve only the perihilar alveoli of the respiratory bronchiole. It supplies all cap- in the walls of the larger airways but normally are
region, supplied mainly by the bronchial artery, and illaries in the alveolar walls that constitute the respira- closed. They open if blood flow is interrupted in either
this blood drains to the azygous system and right tory surface of the lung. system and in certain disease states such as pulmonary
atrium. arteriovenous malformation.
VEINS

All intrapulmonary blood drains to the pulmonary
veins. The veins lie at the periphery of any unit—

28 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-27 Anatomy and Embryology

ULTRASTRUCTURE OF PULMONARY ALVEOLI AND CAPILLARIES

Type I alveolar cell Tight cell Type II alveolar cell Surface-active layer (surfactant)
and nucleus
junctions Lamellar bodies

Capillary Capillary
lumen lumen

Alveolar macrophage

Alveolus (airspace)

Endothelial Endothelial
(loose) cell and
cell junctions nucleus

FINE STRUCTURE OF ALVEOLAR Fused basement
CAPILLARY UNIT membranes

The cellular composition of the alveolar capillary unit Interstitial Capillary
was not recognized until the era of electron microscopy. cell lumen
Before that time, it was thought that a single membrane
separated blood and air at the level of the terminal Interstitium Alveolus
airspace. We now know that, even at its narrowest, the Capillary (airspace)
boundary between blood and air is composed of at least lumen Type II alveolar cell
two cell types (the type I alveolar epithelial cell and the
endothelial cell) and extracellular material, namely, the number of proteins such as aquaporin (AQP-5), T1α, ALVEOLAR CELLS AND
surfactant lining of the alveolar surface, the basement functional ion channels, caveolins, adenosine receptors, SURFACE-ACTIVE LAYER
membranes, and the so-called “endothelial fuzz.” The and multidrug-resistant genes. Type II cells and As illustrated in Plate 1-28, in addition to being larger,
last is composed of mucopolysaccharides and proteo- endothelial cells have long been known to play active the type II alveolar cell is distinguished from the type
glycans (or glycocalyx) that may be involved in signal roles in the metabolic function of the lung by produc- I alveolar cell by having short, blunt projections on
transduction, including mechanotransduction or shear ing surfactant and processing circulating vasoactive the free alveolar surface and lamellar inclusion bodies.
stress at the endothelial surface. Plate 1-27 shows part substances, respectively. In addition, recent research The intracellular origins of the lamellar bodies (LBs)
of a terminal airspace and cross sections of surrounding suggests more complex roles for both of these cell and the exact mechanism for lipid transport into them
capillaries. In humans, the diameter of the alveoli varies types.
from 100 to 300 μm. The capillary segments are much
smaller in diameter (10-14 μm) and may be separated
from each other by even smaller distances. Each alveo-
lus (there are 300 million alveoli in the adult human
lungs) may be associated with as many as 1000 capillary
segments.

The thinness of the cellular boundary between the
blood and the air presents enormous surface area to air
on one side and to blood on the other (∼70 m2 for both
lungs). Given the paucity of organelles, the cells at this
location likely play mainly passive roles in physiologic
and metabolic events involved in the management of
airborne or bloodborne substrates.

Ninety-five percent of the alveolus is lined by epi-
thelial type I cells. The remaining cells are larger
polygonal type II cells. These two cell types form a
complete epithelial layer sealed by tight junctions. The
cellular layer lining the alveoli is remarkably imperme-
able to salt-containing solutions, but little is known
about specific metabolic activities of type I alveolar
cells. Growing evidence suggests a more important role
in the maintenance of alveolar homeostasis than previ-
ously thought, evidenced by the expression a large

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 29

Plate 1-28 Respiratory System

TYPE II ALVEOLAR CELL AND SURFACE-ACTIVE LAYER

Electron microscopic features Surface phase Surface-
active
Lamellar bodies Subphase layer
Mitochondria
Lamellar body extruding contents Tubular
myelin

Multivesicular body

Plasma membrane
of type II cell

Cytoplasm

FINE STRUCTURE OF ALVEOLAR
CAPILLARY UNIT (Continued)

are not known with certainty, although lipid transloca- Freeze-fracture preparation A
tion across the LB membrane is facilitated by the ABCA of a lamellar body with
subfamily of adenosine triphosphate–binding cassette closely apposed, fractured B
transporters. The LB contains the phospholipid com- lamellae. Series of parallel
ponent of surfactant and two small hydrophobic sur- ribs, each ca. 80 Å in width C
factant polypeptide proteins (SP-B and SP-C) that are evident on lamellae A and B,
coreleased from the type II cell by a process similar to the series angled to each ENDOTHELIAL CELL STRUCTURE
exocytosis. Two additional components of surfactant other. Particles or knobs, ca. Details of the fine structure of pulmonary capillary
(large hydrophilic proteins SP-A and SP-D) are synthe- 100 Å in diameter, are endothelial cells are shown in Plate 1-29. The endothe-
sized and released independent of LBs. prominent on lamella C but also lium is of the continuous type (not fenestrated), and the
apparent between ribs. cells are frequently linked by tight junctions. Alveolar
After release into the airspace, surfactant forms a epithelial cells and alveolar capillary endothelial cells
lipid monolayer on the alveolar surface, greatly reduc- each alveolus in humans. Pericytes ensheathed in base- are uniquely interactive and highly codependent during
ing surface tension. Although surfactant production, ment membrane occur around pulmonary alveolar cap- lung development. The ultrastructural features of the
release, and recycling are critical type II cell functions, illaries but less frequently than on systemic capillaries.
these cells are now known to have many additional The pericytes are characterized by having finely
functions, including repopulation of type I cells, clear- branched cytoplasmic processes that approach the
ance, repair, migration to areas of lung injury, and host endothelial cells and a web of cytoplasmic filaments that
defense (including the expression of Toll-like recep- run along the membrane close to the endothelium.
tors). Type II cells also secrete and respond to an Pericytes can be distinguished from fibroblasts in that
array of cytokines and chemokines and have been the latter are free of a basement membrane sheath.
shown to regulate monocyte transmigration across the
epithelium.

Alveolar macrophages are migratory cells and, after
fixation for microscopy, they are usually seen free in the
alveolar space or closely applied to the surface of type
I cells. Alveolar macrophages are characterized by
irregular cytoplasmic projections and large numbers of
lysosomes. Alveolar macrophages are important in the
defense mechanisms of the lungs.

The cellular components of the blood-air barrier fre-
quently consist only of the extremely flattened exten-
sions of endothelial cells and type I alveolar cells. In
other regions, the wall contains such cell types as
smooth muscle cells, pericytes, fibroblasts, and occa-
sional mononuclear cells (including plasma cells).
Smooth muscle cells are found around the mouth of

30 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-29 Anatomy and Embryology

PULMONARY VASCULAR ENDOTHELIUM

Electron microscopic features Higher magnification
of caveola
Alveolus Lumen of
(airspace) capillary Outer leaflet and inner
leaflet of plasma (cell)
Alveolar Junction of membrane
epithelium endothelial
(type I cell) cells (loose Diaphragm
Fused cell junction)
basement Caveola
membranes
(interstitium) Globular particles

FINE STRUCTURE OF ALVEOLAR Tight Plasma Freeze-fracture
CAPILLARY UNIT (Continued) junction of membrane of preparations
epithelial endothelial cell
capillary endothelial cell are in keeping with their cells A. Extracellular
primary roles as fluid barriers and gas transfer facilita- Caveolae aspect of inner
tors. The thickest portion of the cell is in the vicinity Interstitial leaflet of
of the nucleus, where the majority of cytoplasmic cell Vesicle plasma membrane:
organelles, such as mitochondria, Golgi apparatus, coveolae appear
rough endoplasmic reticulum, multivesicular bodies, Fingerlike as pits. Note
microtubules, microfilaments, and Weibel-Palade projection nodules (globular
bodies, reside. However, the more peripheral slender Diaphragm particles) on
extensions of these cells are practically devoid of of caveola surface of
organelles, and may be as thin as 0.1 μm in some Mitochondrion membrane and pits
regions.
Multivesicular B. Cytoplasmic
A growing body of evidence indicates that the body aspect of outer
endothelium plays a large number of important physi- Nucleus of leaflet of
ologic roles at the alveolar level, many of which appear endothelial membrane: caveola
to be mediated by the caveolae intracellulare. The caveo- cell appears as dome.
lae are a subset of membrane (lipid) rafts, present as Globular particles
flask-shaped invaginations of the plasma membrane. apparent
When the pulmonary capillary endothelial cell mem-
brane is freeze fractured, the caveolae appear as pits Scanning electron micrograph
on the inner fracture face and as domes on the outer
fracture face. Intramembranous particles, about 80 to Luminal surface of pulmonary
100 Å in diameter, are randomly scattered on both artery. The endothelial
faces, except in association with caveolae, where they projections range from 250
occur in rings or plaques. These rings correspond to to 350 nm in diameter and
the skeletal rim seen in thin sections. The intramem- 300 to 3000 nm in length.
branous particles also occur on the curved faces of the They may be simple knobs or
caveola membrane. longer arms, some of which
branch or bud. They are
The caveolae contain caveolin proteins, which serve densest over main body of
as organizing centers for signal transduction. Caveolin cells but extend laterally to
proteins have cytoplasmic N and C termini, palmitoyla- overlap adjacent cells
tion sites, and a scaffolding domain that facilitates inter-
action with signaling molecules. Caveolae are implicated vesicles, vastly increasing the surface of the endothe- demonstrated in scanning electron micrographs. The
in a wide variety of cell transport events, including lium. The luminal stoma of the caveola is spanned by a size (250-350 nm in diameter; 300 to ≥3000 nm long)
transcytosis and cholesterol trafficking. Many of the delicate diaphragm composed of a single lamella (by and density of the projections are such that they may
caveolae intracellulares directly face the vascular lumen, contrast with the unit membrane construction of the prevent the formed elements of blood from approach-
but they are also found on the abluminal surface as endothelial plasma membrane and caveola membrane) ing the endothelial surface and have the effect of direct-
that helps create a specialized microenvironment within ing an eddy flow of plasma along the cells. Their
the caveola. function is not entirely known, but they vastly increase
the cell surface area for interaction with soluble ele-
In addition to the caveolae, the endothelial surface ments in the blood.
has numerous fingerlike projections, which are best

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 31

Plate 1-30 Respiratory System

Right paratracheal nodes Left paratracheal nodes
Right superior tracheobronchial nodes
Bronchomediastinal lymphatic trunk Bronchomediastinal lymphatic trunk

Brachiocephalic vein Brachiocephalic vein

Inferior deep cervical
(scalene) node

LYMPHATIC DRAINAGE OF Inferior deep cervical Inferior Virchow node
THE LUNGS AND PLEURA (scalene) node tracheobronchial
(carinal) nodes Thoracic duct
The lymphatic drainage of the lung plays critical roles Internal jugular
in the removal of excess interstitial fluid and particulate vein and jugular Pulmonary Left superior
matter (free or within macrophages) deposited in the lymphatic trunk ligaments tracheobronchial nodes
airspaces and in lymphocyte trafficking and immune
surveillance. Discrepancies exist between the terminol- Right lymphatic duct Routes to (Aortic arch) node of
ogy of the Nomina Anatomica adopted by anatomists for mediastinum ligamentum arteriosum
lung lymphatic routes and the terms commonly and Subclavian vein
conveniently used by clinicians, surgeons, and radiolo- and subclavian Bronchopulmonary
gists. For this reason, in the illustrations, the terms in lymphatic trunk (hilar) nodes
common usage are included in parentheses after the
official Nomina Anatomica designations. Bronchopulmonary Pulmonary (intra-
(hilar) nodes pulmonary) nodes
As the lymphatic channels approach the hilum, lymph
nodes are present in the following distributions: Pulmonary Subpleural
(intra- lymphatic
1. The pulmonary (intrapulmonary nodes) within pulmonary) plexus
the lung, located chiefly at bifurcations of the nodes
large bronchi Interlobular
Subpleural lymph
2. The bronchopulmonary (hilar) nodes situated in lymphatic vessels
the pulmonary hilum at the site of entry of the plexus
main bronchi and vessels Drainage
Inter- follows
3. The tracheobronchial nodes, which anatomists lobular bronchi,
subdivide into two groups: a superior group situ- lymph arteries,
ated in the obtuse angles between the trachea and vessels and veins
bronchi and an inferior (carinal) group situated
below or at the carina (i.e., at the junction of the Drainage
two main bronchi) follows
bronchi,
4. The tracheal (paratracheal) group situated along- arteries,
side and to some extent in front of the trachea and
throughout its course; these are sometimes subdi- veins
vided into lower tracheal (paratracheal) nodes and
an upper group in accordance with their relative Drainage routes
positions
Right lung: All lobes drain to pulmonary Left lung: Superior lobe drains to pulmonary
5. The inferior deep cervical (scalene) nodes situated and bronchopulmonary (hilar) nodes, then and bronchopulmonary (hilar) nodes, inferior
in relation to the lower part of the internal jugular to inferior tracheobronchial (carinal) tracheobronchial (carinal) nodes, left superior
vein, usually under cover of the scalenus anterior nodes, right superior tracheobronchial tracheobronchial nodes, left paratracheal
muscle nodes, and right paratracheal nodes on nodes and/or (aortic arch) node of ligamentum
the way to the brachiocephalic vein via arteriosum, then to brachiocephalic vein via
6. The aortic arch nodes situated under the arch of the bronchomediastinal lymphatic trunk left bronchomediastinal trunk and thoracic
the aorta and/or the inferior deep cervical (scalene) duct. Left inferior lobe also drains to
node pulmonary and bronchopulmonary (hilar)
Beginning centrally, the major lymph channels on nodes and to inferior tracheobronchial
the right side are (1) the bronchomediastinal lymph (carinal) nodes but then mostly to right
trunk, which collects lymph from the mediastinum, and superior tracheobronchial nodes, where it
(2) the jugular lymph trunk. The latter commonly follows same route as lymph from right lung
unites with (3) the subclavian trunk to form a right
lymphatic duct, which in turn joins the origin of the through the interlobular planes, connective tissue septa, the respiratory units—whether acinus, lobule, or
right brachiocephalic vein. In some cases, however, and the pleura. In the bronchi, fine lymph channels in segment—are surrounded by connective tissue and
these three major lymphatic channels join the brachio- the submucosa communicate with much larger lym- have lymphatic plexuses in their walls. They are sepa-
cephalic vein independently. On the left side, the tho- phatic vessels in the adventitia. Beyond this point, rated from the bronchi and arteries, but at least cen-
racic duct curves behind the internal jugular vein to the lymph is collected by the interlobular lymphatics. trally, communicating channels connect the various
enter the right brachiocephalic vein at the junction of The bronchial pathways communicate with the lymph lymphatic systems that form a fine network beneath the
the subclavian vein and internal jugular veins. There vessels along the accompanying pulmonary arteries. pleural surface over the surface of the lungs and the
may or may not be a separate right bronchomediastinal The pulmonary veins that lie at the edge of interlobar fissures.
lymph trunk; if present, it may join the thoracic duct or
enter the brachiocephalic vein independently.

Within the lung, lymphatic plexuses course as two
separate arcades, one along the bronchovascular sheath
(beginning at the level of the respiratory bronchiole)
and the other along the pulmonary veins coursing

32 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS

Plate 1-31 Anatomy and Embryology

DISTRIBUTION OF LYMPHATICS IN LUNGS AND PLEURA

Lymph vessels on bronchi and bronchioles Subpleural lymph vessels Tracheal (paratracheal) nodes
as far as terminal bronchioles Interlobular lymph vessels Superior tracheobronchial nodes

Interlobular lymph vessels Inferior tracheobronchial (carinal) nodes
Bronchopulmonary (hilar) nodes
Respiratory Pulmonary nodes
bronchioles,
alveolar ducts,
and alveoli
free of lymph
vessels

Lymph vessels on
pulmonary artery

Pulmonary ligament
route to posterior
mediastinal nodes

Lymph vessels on
pulmonary vein

Subpleural
lymph vessels

Pleural lymph vessels
visualized through
pleural surface lining

LYMPHATIC DRAINAGE OF tracheobronchial and the right tracheal (paratracheal) lymphatic vessels contain many valves that normally
THE LUNGS AND PLEURA nodes. From there, lymph goes either by the way of the direct the flow toward the hilum. Obstruction in parts
bronchomediastinal trunk to the right brachiocephalic of the system, however, may cause a “backing up”
(Continued) vein, via the inferior deep cervical (scalene) lymph effect with incompetence of the valves, reversal of flow,
nodes to the same vein, or through both of these chan- and opening of collateral channels. It is noteworthy
The network was formerly thought to drain it its nels. On the left side, the course is somewhat different. that in pulmonary edema, the pulmonary lymph vessels
entirety to the hilar nodes, but it has now been shown There, either most or all of the drainage from the upper have been found to be greatly distended (see Plate
to communicate not only with the arterial and venous lobe, after passing through the bronchopulmonary 4-127).
channels but with the interlobular plexuses as well. (hilar) lymph nodes, moves either by way of the tra-
Only the portion of the pleural drainage close to the cheobronchial and tracheal (paratracheal) lymph nodes, Some lymph may leave the lungs through vessels that
hilum supplies the nodes there. The interlobular vessels bronchomediastinal trunk, scalene nodes, and thoracic emerge in the pulmonary ligaments and pass to the
pass to the bronchial, arterial, and venous pulmonary duct to the brachiocephalic vein or by way of the aortic posterior mediastinal lymph nodes. Nagaishi’s textbook
plexuses and to the pulmonary and bronchopulmonary arch nodes to the same termination. From the left lower states that some of the pulmonary drainage may even
nodes. lobe and usually from the lingula, lymph flows to the reach intraabdominal lymph nodes, although a specific
right after passing through the bronchopulmonary transit route is not described. Finally, there are prob-
Almost all the lymph from the lungs eventually (hilar) nodes and goes mostly to the lower tracheobron- ably cross-connections between the right and left tra-
reaches the bronchopulmonary (hilar) lymph nodes, chial (carinal) lymph nodes. It then follows the same cheal (paratracheal) nodes, a situation that may further
with or without passing through pulmonary lymph course as the lymph from the right lung by way of the alter the drainage pathways.
nodes on its way. Some lymph may bypass the hilum right tracheal (paratracheal) nodes—an important point
and go directly to the tracheobronchial lymph nodes. in disease, especially tumors of the left lower lobe. Clinically, the nodal positions are described by the
From the right lung, drainage from the bronchopulmo- regional lymph node classification for lung cancer
nary (hilar) group is to the superior and inferior (carinal) A number of factors may cause deviation from these staging as detailed in Plate 4-49. This classification is
major pathways of lymph drainage. The pulmonary anatomically based and validated, allowing for consist-
ent lymph node mapping used in staging lung cancer.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 33