Question

Sodium balance is monitored by sensing changes in: (Select all correct answers)

a) Blood pressure at afferent arteriole

b) MAP in carotid and aortic arteries

c) Plasma osmolarity via osmoreceptors

d) Blood volume via atrial baroreceptors

e) Plasma sodium levels via sodium receptors

Answer 1

ANSWER :

The sodium concentration in the blood plasma is monitored or detected by specific baroreceptors located on the large carotid and aortic arteries, also sensing mean arterial pressure (MAP) of blood in them. In afferent arteriole of nephrons, the macula densa cells of juxtaglomerular apparatus, detect the change in blood pressure and correspondingly respond to increase or inhibit the renin secretion from JG cells.

The osmolarity in blood plasma is also detected via specific osmoreceptors present in the hypothalamus region of brain, where they sense the change in plasma sodium ions concentration and stimulates consequently the autonomic nervous system to maintain the homeostasis via releasing or inhibiting associated endocrine hormones (e.g.- aldosterone, ADH).

Hence option (a), (b), (c) are the correct answer choice.