In this slide you will find introduction of homeostasis, mechanism of homeostasis, processes involve in homeostasis, nwgative amd positive feedback mechanisms with examples.

1. INTRODUCTION TO HOMEOSTASIS

2. Important variables within the body:
 blood sugar
 fluid balance
 body temperature
 oxygen levels
 blood pressure
 pH
These variables must stay within certain ranges.
Changes in the external environment can cause these
variables to change.

3. Homeostasis
Definition
The process by which a stable internal environment is
maintained despite changes in the external
environment.

5. Dynamic equilibrium
 Homeostasis is also called dynamic equilibrium:
 Conditions do fluctuate, but within an acceptable range

6. Factors affecting homeostasis
 Disease
 Stress
 Lifestyle
 Injury
 Dehydration
 Genetic factors
 Outside temperature

7. Components of a homeostatic control system:
Component Function
Receptor recieves information that something in the
environment is changing
Co-ordinating centre receives and processes information from the
receptor
effector carries out the response initiated by the co-
ordinating centre

8. Example of homeostasis in action
Components Example
Receptor Cutaneous receptors of
the skin
Control centre Brain
Effector Blood vessels and
sweat glands in the skin

10. The hypothalamus
 Part of the brain
 Often serves as the co-ordinating centre:
 Receives messages from monitors
 Initiates a hormonal/nervous response

11. How is dynamic equilibrium
maintained?
 Feedback systems
 Negative feedback
 Positive feedback

12. Negative feedback
 Negative feedback: Response triggered by changed
conditions serves to reverse the change
 E.g., Body temperature increases  Skin blood vessels
dilate  Body temperature decreases

13. Body temperature
increases
Hypothalamus
sends a message
to blood vessels
Skin blood vessels
dilate
Body temperature
decreases
Normal
body
temperature

14. Positive feedback
 Positive feedback: The response triggered by changing
conditions serves to move the variable even further away
from its steady state
 E.g., uterine contractions are stimulated by oxytocin 
baby moves towards cervix  more oxytocin is released

17. Role of various systems in homeostasis
 Respiratory system, blood and kidneys helps in
regulating pH, of ECF, which is 7.4.
 Pancreas regulates blood glucose levels with the
relese of insulin or glucogan.
 Skin, respiratory, digestive, excretery, nervous system
and skeletal muscles are involved in maintaining body
temperatur of 37.5.
 Digestive system and circulatory systems play major
role in supply of nutrients to cells.

18.  Respiratory system supply oxygen to body cells and
remove carbon dioxide from body.
 Kidneys are involved in excretion of waste products.
 Hormones are to be synthesized and released from
endocrine glands in approprite quantities.

19. THANK YOU