The loop of Henle is composed of which components?

The loop of Henle is composed of which components?

• A. Descending limb, loop, and ascending limb
• B. Descending limb only
• C. Ascending limb only
• D. Collecting duct

Answer: (A)

The loop of Henle consists of two parts that form a U-shaped segment: a descending limb that goes into the medulla and an ascending limb that returns toward the cortex. The descending limb is permeable to water, concentrating the filtrate as it descends, while the ascending limb reabsorbs ions and is relatively impermeable to water, helping establish the medullary osmotic gradient. The collecting duct is a separate structure that collects urine from multiple nephrons and is not part of the loop itself. So, the description that includes both the descending and ascending limbs (the loop itself) best identifies the components of the loop of Henle.

The loop of Henle consists of two parts that form a U-shaped segment: a descending limb that goes into the medulla and an ascending limb that returns toward the cortex. The descending limb is permeable to water, concentrating the filtrate as it descends, while the ascending limb reabsorbs ions and is relatively impermeable to water, helping establish the medullary osmotic gradient. The collecting duct is a separate structure that collects urine from multiple nephrons and is not part of the loop itself. So, the description that includes both the descending and ascending limbs (the loop itself) best identifies the components of the loop of Henle.