Question

Complete the following paragraph by selecting the option that correctly fills the blanks (i) - (iv).
The kidneys have built-in mechanisms for the regulation of glomerular filtration rate. One such efficient mechanism is carried out by (i). It is a special sensitive region formed by cellular modifications in the (ii) and the (iii) at the location of their contact. A fall in GFR can activate the JG cells to release (iv) which can stimulate to glomerular blood flow and thereby brings GFR back to normal.

• A. ANF PCT Efferent arteriole Angiotensin
• B. ANF DCT Afferent arteriole Renin
• C. JGA PCT Efferent arteriole Angiotensinogen
• D. JGA DCT Afferent arteriole Renin

Answer 1

The correct option is D JGA DCT Afferent arteriole Renin

The amount of the filtrate formed by the kidneys per minute is called the glomerular filtration rate (GFR). This in a healthy individual is approximately 125 ml/ minute, i.e., 180 litres per day. Three important intrinsic mechanisms provide autoregulation of GFR.

1. Myogenic mechanism.

2. Juxtaglomerular mechanism.

3. Neural control.

2. Juxtaglomerular mechanism: It is an efficient mechanism for regulation of GFR. It is formed by distal convoluted tubule and him afferent arteriole at the location of their contact. Its cells secrete enzymes like renin that modulate blood pressure and thus renal blood flow. This regulates GFR.

So, the correct answer is 'JGA, DCT, Afferent arteriole, Renin'.