1. Homeostasis
Dr. Sadaf Mumtaz
29/11/11

2. AIMS Introduction to Physiology Levels of Organization in the body
Homeostasis
Homeostatic control systems

3. What is Physiology?

4. Levels of organization in the body

5. Homeostasis
Homeo means ‘the same’; and stasis means ‘to stand or stay’
Maintenance of ‘a relatively or nearly’ stable internal enviroment

6. Significance of internal Enviroment

7. Differences between ECF & ICF

9. Contribution of body systems in maintaining homeostasis

10. Homeostatic control systems
Grouping of control systems
Intrinsic
Extrinsic
Negative and positive feedback and feedforward mechanisms

11. Properties of control systems
The direction of correction will be always towards stability.
After the error is sensed, there is a delay in onset of correction. 
The correction is proportional to the magnitude of error. 

12. The effectiveness of a particular control system can be assessed by the calculation of gain

13. 1. Blood pressure= 100 to 175mmHg
Correction = Adjustment – Abnormal increase
= 125 – 175
= -50
Error = 25
Gain = Correction/Error
= -50/25 = -2
2. Blood pressure= 100 to 175mmHg
= 105 – 175
= -70
Error = 5
= -70/5 = -14

14. Negative feedback

15. Positive feedback

16. Feedforward mechanism

17. Thanks

18. Performance based on knowledge
Temperature Roll number 1-30
Blood pressure
Exercise
Digestion