Juxtamedullary nephrons – Physiology MCQ

Juxtamedullary nephrons:
A. Have smaller sized glomeruli
B. Possess short loops of Henle
C. Have slow rate of filtration
D. Both descending and ascending limbs of loop of Henle contain thin segments.

Correct answer : D. Both descending and ascending limbs of loop of Henle contain thin segments.

Juxtamedullary and cortical nephrons

• Juxtamedullary nephrons comprise 14-15% nephrons in the kidney.
• They have large sized glomeruli which are situated at the junction of the cortex and medulla of the kidney.
• The rate of filtration is high.
• They have long loops of Henle which penetrate into the medulla.
• Their Henle loops manifest vascular supply in the form of vasa recta.
• Both descending and ascending limbs of loop of Henle contain thin segments. (In cortical nephrons, descending limb contains a thin segment whereas the ascending limb contains a thick segment.)

Ref: Textbook of Physiology, A K Jain, 3rd edition, Volume 2, page 520.
Image credits: Holly Fischer. Licensed under the Creative Commons Attribution 3.0 Unported license. http://open.umich.edu/education/med/resources/second-look-series/materials