Homestatis

Question 1

what is homeostasis?

Answer 1

A condition in which the internal environment of the body remains relatively constant despite changes in the external environment.

Question 2

what is involved in autoregulation? (intrinsic)

Answer 2

cell,tissue, organ adjusts activity itself

Question 3

what is involved in extrinsic regulation?

Answer 3

nervous system

endocrine system

Question 4

explain the receptor/target complex?

Answer 4

Highly specific /localised e.g. FSH or more general widespread effect e.g. thyroxine.
Most hormones are amino acid based and therefore water soluble requiring a receptor on target cells.
Some are steroidal, synthesised from cholesterol therefore lipid soluble, can pass through cell membrane to receptors in cells.

Question 5

what is target cell activation influenced by?

Answer 5

Number of receptor sites on or in a cell for a particular hormone;
Circulating blood levels
 of the hormone;
Strength of the 
Binding.

Question 6

describe osmoregulation?

Answer 6

The control of water concentration in blood and body fluids
The pituitary gland controls blood water concentration by producing ADH
ADH is carried by the blood to the kidneys
ADH increases the permeability of the kidney tubules allowing water to be reabsorbed from the tubules into the blood.
If blood water concentration fails more absorption is needed so less water is lost in urine. ADH production is increased