Question

The peritubular capillaries of the nephron arise from the
A. Afferent arteriole
B. Efferent arteriole
C. Renal artery
D. Arcuate artery.

Answer 1

Hint: The extended network of efferent arteriole which wrap around the PCT and DCT part of nephron, that help in reabsorption of important molecules such as glucose, ions and water, which is necessary for regulation for proper functioning.

Complete answer:
The Peritubular capillaries are arises from the efferent arteriole which form network of tiny blood vessels, and wrap around the proximal convoluted tubule and distal convoluted tubule which facilitate the reabsorption and secretion between blood and inner lumen of nephron and vasa rectum reaches to the medulla to approach loop of Henle. The efferent arterioles take the blood from the glomerulus. Necessary ions, minerals, glucose and amino acid are reabsorbed by peritubular capillaries through active transport and excess of water and other ions are secreted into the tubule.
a. Afferent arteriole:- This arteriole arises from the renal artery, afferent arteriole latter gives rise to capillaries of the glomerulus, this arteriole brings the blood to glomerulus for the filtration purpose. These afferent arterioles play a significant role in the regulation of blood pressure as a part of tubule glomerular feedback mechanism.
c. Renal artery:- Renal arteries are the blood carry vessels which bring the blood from the heart to the kidneys. This arises from the left side of the abdominal aorta. This renal artery carries a large amount of total blood flow to the kidneys for the filtration purpose.
d. Arcuate artery :- these are also known as arciform arteries, which present at the border of renal cortex and renal medulla and these are for the renal circulation.

So, the correct answer is option B.

Note: The Efferent arteriole take away the blood from the glomerulus and afferent Arteriole bring the blood from renal artery which also brings the blood from the different part of body, to the glomerulus for filtration purpose. Where unnecessary compounds are filtered out.