ANATOMY

HOMEOSTASIS , LEVEL OF
ORGANIZATION

CHAPTER 1 { HUMAN BODY}

WHAT IS HOMEOSTASIS

• Is quite crucial for the survival of organisms.
• Is a self –regulating process that regulates internal variables

necessary to sustain life.
• Is a mechanism that maintains a stable internal environment despite

the changes present in the external environment.
• Controlling a host of variables ranging from body temperature, blood

pH, blood glucose levels to fluid balance, sodium, potassium and
calcium ion concentrations

REGULATION OFHOMEOSTASIS

>The regulation of homeostasis depends on three mechanisms

• RECEPTOR

➢As the name suggests, the receptor is the sensing component responsiblefor monitoring
and responding to changes in the external or internal environment.

➢ Cutaneous receptors of the skin.

• CONTROL CENTER

➢The control centre is also known as the integration centre. It receives and processes and
processes information from the receptor.

➢Brain.

• EFFECTOR

➢Responds to the commands of the control centre. It could either oppose or enhance the
stimulus.

➢Blood vessels and sweat glands in the skin

Input ›nlormatior› ContDl Chilput
sent along different semi sior›qellerenl

hway to

‹I* Change detected Imbalance Haspur›su ot elector

”—” by IGC0 lOf (too much) feects back tc inftuence
magnitude of stimulus

ar›d returns variable

" Produ. Imbalance
in car iabIe (too little)

Homeostasis is a property of a human biological system where the sett-regulating
process tends to maintain the balance for the survival. The regulation takes place
in a defined intornal onvironment

NEGATIVE AND POSITIVE FEEDBACK MECHANISMS

NEGATIVE FEEDBACK MECHANISMS POSITIVE FEEDBACK MECHANISMS

➢ A mechanism that restore the ➢Mechanism that promote a condition
body to a normal state farther from normal levels of function
Increase the original stimulus
Shut off or reduce the intensity of (disturbance).
the original stimulus
➢Blood clotting and labor
➢ body temperature, heart rate, contractions
blood pressure, breathing rate,
blood levels of glucose, oxygen,
carbon dioxide, and minerals.

HOMEOSTATIC IMBALANCE

LEVELS OF ORGANIZATION

❖ CHEMICAL LEVEL

• Interaction between atoms into molecules

❖ CELLULAR LEVEL

• Basic living units; have common characteristics, differ in structure and function

❖ TISSUE LEVEL

• A group of cells of similar structure and function: epithelial, connective, muscle, nervous

❖ ORGAN LEVEL

• Two or more tissue types together perform one or more common function: eye,
skin, stomach, heart, etc.

❖ ORGAN SYSTEM LEVEL

• A group of organs of a common function: integumentary, skeletal, muscular,
nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, &
reproductive

❖ ORGANISMAL LEVEL

THE LANGUAGE OF
ANATOMY

By: Nur Bahauddin Nizar Bin Nor Shuhaimi
(2022811028)

REGIONAL TERMS

Anterior Body Posterior Body
Landmarks:
landmarks: Scapula,

orbital, Vertebral,Gluteal,
thoracic,abdominal,pubic Popliteal & calceneal

,femoral &tarsal

Interior Body
Surface: Theplanta
region, the sole of

the foot

BODY REGION

AXIAL SKELATON APPENDICULAR
SKELETON

AXIAL SKELETON

HEAD,NECK,THORAX,ABDOMEN & PELVIC

APPENDICULAR SKELETON

UPPER EXTREMITIES & LOWER
EXTREMITIESt

BODY PLANES AND
SECTIONS

THE HUMAN
BODY

BODY CAVITIES

NUREEN QISTINA PUTRI 2022801484 SR1131C

Introduction

What are body cavities ?

A body cavity is a fluid-filled space inside the body that holds
and protects internal organs . Human body cavities are
separated by membranes and other structures . The two
largest human body cavities are the ventral cavity and
the dorsal cavity . These two body cavities are subdivided into
smaller body cavities



Ventral Cavity

The ventral cavity is at the anterior (or front) of the trunk. Organs contained within this body cavity include
the lungs, heart, stomach, intestines, and reproductive organs. The ventral cavity allows for considerable
changes in the size and shape of the organs inside as they perform their functions. Organs such as the
lungs, stomach, or uterus, for example, can expand or contract without distorting other tissues or
disrupting the activities of nearby organs.

The ventral cavity is subdivided into the thoracic and abdominopelvic cavities.

•The thoracic cavity fills the chest and is subdivided into two pleural cavities and the pericardial cavity. The
pleural cavities hold the lungs, and the pericardial cavity holds the heart.
•The abdominopelvic cavity fills the lower half of the trunk and is subdivided into the abdominal cavity
and the pelvic cavity. The abdominal cavity holds digestive organs and the kidneys, and the pelvic cavity
holds reproductive organs and organs of excretion.

Dorsal Cavity

The dorsal cavity is at the posterior (or back) of the body, including both the head and the back of the
trunk. The dorsal cavity is subdivided into the cranial and spinal cavities.

•The cranial cavity fills most of the upper part of the skull and contains the brain.
•The spinal cavity is a very long, narrow cavity inside the vertebral column. It runs the length of the trunk
and contains the spinal cord.

The brain and spinal cord are protected by the bones of the skull and the vertebrae of the spine. They are
further protected by the meninges , a three-layer membrane that encloses the brain and spinal cord. A
thin layer of cerebrospinal fluid is maintained between two of the meningeal layers. This clear fluid is
produced by the brain, and it provides extra protection and cushioning for the brain and spinal cord.

BODY CAVITIES

Dorsal Cavity Ventral Cavity
• Cavity in the BACK of the body • Cavity in the FRONT of the body

Cranial Cavity Spinal Cavity Thoracic Cavity Abdominopelvic
➢ Brain ➢ Spinal Cord Cavity

Pleural Mediastinum Abdominal Pelvic
cavities
➢ Liver ➢ Bladder
➢ Lungs ➢ Stomach ➢ Reprod
➢ Pancreas ➢ Organs
➢ Trachea , Esophagus ➢ Intestines

Pericardial
Cavity

➢ Heart , Great Vessels

Main Body Cavities and Their Organ Contents

Cavity Contents
Dorsal ( posterior ) Cranial cavity and spinal cavity

Cranial Brain

Spinal Spinal cord
Ventral ( anterior ) Thoracic cavity , abdominopelvic cavity

Thoracic Mediastinum ( heart , great vessels
,esophagus , trachea ) , lungs , pericardial
and pleural cavities

Abdominopelvic Abdominal cavity and pelvic cavity

Abdominal Stomach , intestines , liver , spleen
,pancreas , kidney , gallbladder ,
peritoneal cavity

Pelvic Urinary bladder , rectum , internal
portions of reproductive system ,
peritoneal cavity

ABDOMINOPELVIC REGIONS AND QUADRANTS

• Quadrants : 1 transverse and 1 median sagittal plane
pass through the umbilicus ( belly button ) at right
angles .

• Quadrants :
➢ Right upper quadrant ( RUQ )
➢ Left upper quadrant ( LUQ )
➢ Right lower quadrant ( RLQ )
➢ Left lower quadrant ( LLQ )

• Nine regions defined by 4 planes

• Anterior view of the abdominopelvic cavity showing the superficial
organs

OTHER BODY CAVITIES

1 . Oral & digestive 2 . Nasal cavity 3 . Orbital cavities
cavities

4 . Middle ear cavities 5 . Synovial cavities

NERVOUS SYSTEM

-ORGANISATION OF NERVOUS SYSTEM

i.Division of nervous system
ii.Central and peripheral
nervous system
iii.Nervous tissue
iv.Central of nervous system
(brain & spinal cord)
v.Spinal cord

DIVISION OF THE NERVOUS SYSTEM

WHAT ARE THREE DIVISIONS OF THE NERVOUS SYSTEM?

The The sympathetic The Enteric Nervous
Parasympathetic nervous system System
Nervous System

Central and Peripheral nervous system

-The central nervous system is
made up of brain and spinal
cord.

-The peripheral nervous
system is made up of
nerves that branch off
from the spinal cord and
extend to all parts of the
body.

CENTRAL NERVOUS SYSTEM
BERPUSAT DI OTAK DAN TULANG
BELAKANG

NERVOUS TISSUE

What are the 3 nervous tissue?

.Connective Tissue
.Epithelial Tissue
.Muscular Tissue

What is nervous tissue and its types?

-Nervous tissue is composed of neurons, also called nerve
cells, and neuroglial cells. Four types of neuroglia found in
the CNS are astrocytes, microglial cells, ependymal cells,
and oligodendrocytes. Two types of neuroglia found in the
PNS are satellite cells and Schwann cells.

What is nervous tissue function?

Nervous tissue is found in the brain, spinal cord,
and nerves. It is responsible for coordinating and
controlling many body activities. It stimulates
muscle contraction, creates an awareness of the
environment, and plays a major role in emotions,
memory, and reasoning.

CENTRAL NERVOUS SYSTEM (BRAIN & SPINAL CORD)

-The central nervous system (CNS) is made up of the brain and spinal
cord. It is one of 2 parts of the nervous system. The other part is the
peripheral nervous system, which consists of nerves that connect the
brain and spinal cord to the rest of the body. The central nervous
system is the body's processing centre.

SPINAL CORD

What are the 3 main parts of the spinal cord?

-Cervical (neck)
-Thoracic (chest)
- Lumbar (lower back).

What is spinal cord and it's function?

-The spinal cord is a long bundle of nerves and
cells that extends from the lower portion of
the brain to the lower back. It carries signals
between the brain and the rest of the body.

TAMATLAH SUDAH PRESENTATION SAYA,
MOHON MAAF JIKA ADA KEKURANGAN,
KERANA KESEMPURNAAN ITU KETIKA
KAU
DAN DIA DISATUKAN.

CUKUP SEPI TANPA KEKASIH,
PENUTUP SEKIAN DAN TERIMA KASIH.

( THE NERVOUS SYSTEM )
NURNISRISYA 2022825088 SR1131C

DIENCEPHALON

THE BRAIN 4 DIVISIONS OF BRAIN - Located deep to the
cerebrum
- Connects the midbrain with
the cerebral hemispheres

BRAIN STEM - Composed of thalamus, hypothalamus and epithalamus
• Thalamus – relay station for sensory impulses
- Relays messages between passing to the sensory cortex for
the spinal cord and the interpretation
cerebrum. • Hypothalamus – autonomic control center,
maintains water balance and regulates thirst,
1. Midbrain eating behaviour, gastrointestinal activity,
• Mainly fiber tracts body temperature and the activity of the
• Connects the pons and cerebellum with the anterior pituitary glands
• Epithalamus – includes the pineal gland which
cerebrum secretes the melatonin (helps regulate the
sleep-wake cycle)
2. Pons
• Connecting bridge between the medulla oblongata and the CEREBELLUM

midbrain
• Has fiber tracts and nuclei involved in respiration

3. Medulla oblongata • Located behind the pons (brain posterior to the 4th
• Fibers of motor tracts from the motor cerebral cortex cross over (decussate)
ventricle)
in the medulla oblongata before entering the spinal cord • Large and cauliflower-like
• Contains vital cardiac, vasomotor, and respiratory center (breathing, HR, BP, • Mainly a coordination center for muscular

etc) movement, involved with balance, precision, timing,
• Regulates vomiting, sneezing, coughing and swallowing
and body position

THE BRAIN 4 DIVISIONS OF BRAIN

CEREBRUM / CEREBRAL HEMISPHERES

- The largest part of brain
- The cerebrum initiates and coordinates movement and regulates temperature
- Consists of 2 hemispheres; right and left
- Involved in logical reasoning, moral conduct, emotional responses, sensory interpretations, and the initial of voluntary muscle activity

- Divided into 5 lobes: - Functional areas of the
1. Parietal lobe cerebral cortex include:
2. Frontal lobe 1. Motor areas – control
3. Temporal lobe
4. Occipital lobe precise or skilled
5. Insula ( buried deep within the voluntary movements
2. Sensory areas –
lateral sulcus and forms part of its concerned with
floor) conscious awareness of
sensation
3. Association areas –
intellect, cognation,
reasoning, judgment etc

THE BRAIN PROTECTION OF THE BRAIN CEREBROSPINAL FLUID/CSF

MENINGES - Brain is covering by 3 layer protective - Formed by the choroid plexus from blood
membranes (connective tissues) : dura plasma, circulates through the ventricle and
mater, arachnoid mater, pia mater into the subarachnoid space.
- Between the arachnoid and pia - Support and watery cushions the brain and
meter is the subarachnoid space, spinal cord and helps to nourish them
which contains cerebrospinal fluid

- Reflects the relative impermeability of the epithelium of the BONE
capillaries of the brain
BLOOD-BRAIN BARRIER - It allows water, respiratory gases, essential nutrients, and
fat-soluble molecules to enter the neural tissue, but prevent
entry of other, water- soluble, potential harmful substances

NERVOUS SYSTEM

THE

SPINAL CORD

MUHAMMAD ARIFF HAZIEQ SR1131C

INTRODUCTION

THE CYLINDRICAL BUNDLE OF
NERVE FIBRES AND ASSOCIATED
TISSUE WHICH IS ENCLOSED IN

THE SPINE AND CONNECTS
NEARLY ALL PARTS OF THE BODY

TO THE BRAIN, WITH WHICH IT
FORMS THE CENTRAL NERVOUS

SYSTEM

1. Gross Anatomy
and Protection

1 Two-way impulse conduction pathway and
a reflex center

2 Conducting impulse between brain and
peripheral nerves

3 Controls many reflex actions

2. Cross-sectional
Anatomy

'H' shaped the gray matter surrounded by white

1 marker

Gray matter consist of cell bodies, dendrites,
axon neuroganglia
White matter consist of nerves with its
pathway

2 Axons of sensory neurons enter the posterior
aspect of the cord and form the dorsal cord

3 Conduction pathway comprised of:
1. Ascending tract

2. Descending tract

The Peripheral
Nervous System

Consist of sensory receptors, nerves conducting impulses to and
from the CNS, their associated ganglia and motor endings
Nerves extend between skin, muscles, visceral organs and glands to
and from the CNS
Divided into somatic and autonomic nervous system
Prominent nerves involve are cranial and spinal nerves

The Peripheral Somatic Nervous System
Nervous System
Sympathetic Division
Autonomic Nervous Parasympathetic Division
System

Sensory Receptors

Are specialized to respond to environmental changes (stimuli)
Simple (general) receptors for pain, touch, pressure and temperature
found in the skin, skeletal muscles, tendons and visceral organs
Complex receptors (sense organs) serve the special senses (vision,
hearing, equilibrium, smell and taste)

Nerves and Associated Ganglia

A nerve is a bundle of neuron fibers in the PNS wrapped in connective
tissue covering
Each fibers is enclosed by an endonerium, fascicle of fibers is
wrapped by perinerium, and the whole nerve is bundled by the
epinerium
Ganglia are collections of neuron cell bodies associated with nerves
in the PNS; e.g: the dorsal root (sensory) ganglia and autonomic
(motor) ganglia

Cranial Nerves

12 pairs and originated from the brains
Innervate the head and neck
Cranial nerves are numbered from anterior to posterior in order of
emergence from the brain
Only the vagus nerves (X) exxtend into the thoracic and abdominal
cavities

SPINAL NERVES

Consist of nerves extend between skin, muscles, visceral organs and glands,

CNS

Divided to somatic and autonomic system

31 PAIRS OF SPINAL NERVES SPINAL NERVES DIVIDED
SPINAL NERVES EMERGING INTO

1. 8 cervical (C1-C8) 1. cervical enlargement- 1.ventral (anterior,motor) root-
2. 12 thoracic (T1-T12) innervate the upper contain efferent nerve fibres
3. 5 lumbar (L1-L5) limbs and convey motor information
4. 5 sacral (S1-S5)
5. 1 coccygeal (C0) 2. lumbar enlargement- 2.dorsal (posterior, sensory) root-
innervate the lower contain afferent nerves fibers,
limbs which enter cord with sensory
infrmation

The Reflex Arc

A reflex is a rapid, involuntary motor response to a stimulus
Has 5 elements: receptor, sensory neuron, integration center, motor
neuron and effector
Reflex arc is conduction pathway for a reflex action involves sensory
cell, effector cell, one or more nerve cells
Reflexes divided into:

1. Somatic reflex (effectors are the muscles)
2. Visceral reflex (effectors are the smooth and cardiac muscles)

Somatic Nervous System

Composed of:
1. Somatic afferent (sensory) division
2. Somatic efferent (motor) division

Somatic afferent division conveys sensory information from the skin,
skeletal muscles, tendons, joints, eyes, tongue, nose and ears to
spinal cord and brain via the spinal and some cranial nerves
Somatic efferent division conduct impulse from the CNS to skeletal
muscle