Question

Which part of the nephron is found in medullary rays of the kidney ?
A) Loop of Henle
B) renal corpuscle
C) distal convoluted tubules
D) proximal convoluted tubules

Answer 1

Hint: This is the inner region of the kidney’s parenchyma consisting of renal pyramids, the triangular structure that contains the nephron’s dense network and the loop of Henle, the U-shaped portion of the nephron tubule.

Complete answer:
The Loop of Henle is found in the medulla region of the kidneys and is a hairpin shaped loop that features a descending and an ascending limb. The ascending limb continues as another highly coiled tubular region is called the distal convoluted tubule (DCT). The distal convoluted tubule of the various nephrons opens into a straight tube, called a collecting duct. Many of these ducts converge and open into the pelvis through medullary pyramids within the calyces. The portion of a nephron that starts from the proximal convoluted tubule (PCT) to the distal convoluted tubule is named after its discoverer, the German anatomist Friedrich Gustav Jakob Henle, the loop of Henle.

Additional information:
-The malpighian body, PCT, and DCT of the nephron are situated within the cortical area of the kidney, whereas the loop of Henle dips into the medulla.
-Its main function is to make a degree gradient within the medulla of the kidney. Through a countercurrent multiplier system, which uses electrolyte pumps, the loop of Henle creates an area of high urea concentration deep in the medulla, near the papillary duct in the collecting duct system. -Water present in the filtrate inside the papillary duct flows through aquaporin channels, moving passively down its concentration gradient. By this process reabsorbs of water take place and concentrated urine is created for excretion.

So, the correct answer is option A) ‘Loop of henle’.

Note:
-The descending limb of the loop of Henle is highly permeable to the water but is relatively less permeable to the ions and urea and thus, mainly water reabsorption takes place in this part.
-The ascending limb of the loop of Henle is relatively impermeable to the water but is permeable to the ions and thus, the ions are reabsorbed in this part making the urine dilute.