Osmoregulation

Question 1

Define: osmoregulation

Answer 1

The regulation of body fluids, including water content and solute concentration

Question 2

What is caused from water imbalance?

Answer 2

Imbalance of electrolyte (mineral salts) and solute concentration

Question 3

Describe a stimulus response model for low water levels

Answer 3

Stimulus: decreased water levels, increase solute concentration
Receptor: osmoreceptors in the hypothalamus
Modulator: hypothalamus sends to pituitary gland to release antidiuretic hormone; hypothalamus sends a signal from the thirst centre to stimulate the sensation of thirst.
Effector: kidney tubules, which become more permeable to water; thirst behaviour stimulated
Response: increased water reabsorption and decreased urine volume; increased water intake.

Question 4

What to osmoreceptors monitor?

Answer 4

Osmolarity (solute concentration) of blood plasma

Question 5

Describe a stimulus response model for high water levels

Answer 5

Stimulus: increase in water level and decrease in solute concentration
Receptor: osmoreceptor cells in the hypothalamus
Modulator: hypothalamus sends signal to the pituitary gland to inhibit ADH release
Effector: kidney tubules become less permeable to water
REsponse: decreased water reabsorption, increased volume expelled in urine