Regulation of osmolarity

Question 1

How is ADH secretion controlled?

Answer 1

• Primary control is plasma osmolarity: When the effective OP of the plasma increases, the rate of discharge of ADH-secreting neurons in the SO and PVN is increases resulting in an increased release of ADH from the posterior pituitary.
• Changes in neuronal discharge are mediated by osmoreceptors in the anterior hypothalamus, close to the SO and PVN.
• Other receptors in the lateral hypothalamus mediate thirst.

Question 2

Where are low P receptors located?

Answer 2

in the L and R atria and great veins

Question 3

Where are high P receptors located?

Answer 3

the carotid and aortic arch baroreceptors