Hormonal Regulation of Kidney Function — NEET Biology
✅ Asked in NEET 2026The functioning of the kidneys is efficiently monitored and regulated by hormonal feedback mechanisms involving the hypothalamus, JGA and to a certain extent, the heart. Osmoreceptors in the body are activated by changes in blood volume, body fluid volume and ionic concentration. An excessive loss of fluid from the body can activate these receptors which stimulate the hypothalamus to release antidiuretic hormone (ADH) or vasopressin from the neurohypophysis. ADH facilitates water reabsorption from latter parts of the tubule, thereby preventing diuresis. An increase in body fluid volume can switch off the osmoreceptors and suppress the ADH release to complete the feedback. ADH can also affect the kidney function by its constrictory effects on blood vessels. This causes an increase in blood pressure. An increase in blood pressure can increase the glomerular blood flow and thereby the GFR. The JGA plays a complex regulatory role. A fall in glomerular blood flow/glomerular blood pressure/GFR can activate the JG cells to release renin which converts angiotensinogen in blood to angiotensin I and further to angiotensin II. Angiotensin II, being a powerful vasoconstrictor, increases the glomerular blood pressure and thereby GFR. Angiotensin II also activates the adrenal cortex to release Aldosterone. Aldosterone causes reabsorption of Na+ and water from the distal parts of the tubule. This also leads to an increase in blood pressure and GFR. This complex mechanism is generally known as the Renin-Angiotensin mechanism. An increase in blood flow to the atria of the heart can cause the release of Atrial Natriuretic Factor (ANF). ANF can cause vasodilation (dilation of blood vessels) and thereby decrease the blood pressure. ANF mechanism, therefore, acts as a check on the renin-angiotensin mechanism.
NTA tests your understanding of how ADH, renin-angiotensin mechanism, and ANF work together to regulate kidney function and blood pressure. Students often confuse which hormone does what: ADH increases water reabsorption, renin-angiotensin increases blood pressure and Na+ reabsorption, while ANF opposes these effects by causing vasodilation. The key trap is forgetting that these are interconnected feedback mechanisms—ADH responds to osmoreceptors detecting fluid loss, while the renin-angiotensin system responds to blood pressure drops. Remember: ADH and renin-angiotensin both increase blood pressure and fluid retention, but ANF decreases blood pressure—this opposition is crucial for exam questions asking which hormone would be released in specific scenarios.
This paragraph was tested 5 times in NEET.
Arrange the events of Renin-Angiotensin mechanism in correct order: A. Increase in BP and GFR; B. Reabsorption of Na+/water due to Aldosterone; C. Fall in GFR; D. Vasoconstriction by Angiotensin II and aldosterone release; E. Renin converts Angiotensinogen to Angiotensin I, then II.
Which statements are correct? A. An excessive loss of fluid switches off osmoreceptors B. ADH facilitates water reabsorption C. ANF causes vasodilation D. ADH increases blood pressure E. ADH decreases GFR Choose the correct option:
[NEET 2022 Phase 2] Select the correct statements: (a) Angiotensin II activates the cortex of adrenal gland to release aldosterone. (b) Aldosterone leads to increase in blood pressure. (c) ANF acts as a check on renin-angiotensin mechanism. (d) ADH causes vasodilation. (e) Vasopressin is released from adenohypophysis. Choose the correct option:
Which of the following would help in the prevention of diuresis?
A decrease in blood pressure/volume will not cause the release of:
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.