HOMEOSTASIS , LEVEL OF ORGANIZATION

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 responsible for
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 POSITIVE FEEDBACK
MECHANISMS
MECHANISMS
Mechanism that promote a
 A mechanism that restore condition farther from normal
the body to a normal levels of function Increase the
state original stimulus (disturbance).

Shut off or reduce the intensity Blood clotting and
of the original stimulus labor contractions

 body temperature, heart
rate, 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