Physiology

Module 1

--> study of function in living organisms

--> mechanisms which they control internal environment

--> explains physical & chemical factors of function and disease

Homeostasis <-- maintenance of internal environment

Internal environment <-- interstitial fluid & blood plasma

External environment <-- outside body, contents digestive, respiratory & urogenital tracts

--> maintains homeostasis via (+) & (-) feedback

Negative Feedback Control Systems

--> all of them contain same components

--> Ex. heat @ house

--> controlled variable (heat), detected by sensor, shuts off own production by effector (furnace)

Body Temperature (Set pt. 37°C)

--> temp. could drop to 35°C

--> detected by sensors in nervous systems

--> signals control centre in hypothalamus

--> activates organs & systems to generate heat

--> once back to set point , regulates

Positive Feedback Control Systems

--> controlled variable stimulates its own production

--> large amounts of controlled variable produced quickly

Ex. have impulses, ovulation

Positive and Negative Feedback Controlled by

1. Nervous System

--> rapid

2. Endocrine System

--> slow