Long Loops of Henle: The Secret to Concentrated Urine

Long Loops of Henle: The Secret to Concentrated Urine

Question 1. Juxtamedullary nephron.
Answer:

Based on the situation of renal corpuscles, nephrons are of two types.

1. Cortical nephron.

2. Juxtamedullary nephron.

Juxtamdullary nephron:

• It is present at the junction of the cortex and medulla.
• It consists of long Henle’s loop which penetrate deep into the medulla.
• Its vascular supply is formed vasa recta.
• It helps in concentration of urine.

Question 2. Proximal convoluted tubule.
Answer:

It is the coiled portion arising from Bowman’s capsule.

• It is situated in the cortex near the glomerulus.
• It consists of single layer of cuboidal cells bordered by microvilli.
• It is 14 mm long and has diameter of 55 μ.

Function:

• About 80% of active transport of sodium occurs in proximal convoluted tubule.

Question 3. Functions of distal convulated tubule. (or) Draw flowchart of reninangiotensin mechanism.
Answer:

The cells of distal convoluted tubule gets modified and form macula densa.

• Macula densa forms part of juxta – glomerula apparatus.
• These cells function as chemoreceptors.
• They are stimulated by a decreased Na+ ions nd thereby causing increased renin release.