Which network of capillaries surrounds the juxtamedullary nephrons in the kidney?

• A. Peritubular capillaries
• B. Hepatic portal veins
• C. Vasa recta
• D. Glomerular capillaries

Answer: (C)

Verified step by step guidance

1. Understand the anatomy of the kidney: The kidney contains nephrons, which are the functional units responsible for filtering blood and forming urine. Juxtamedullary nephrons are a specific type of nephron located near the medulla of the kidney.
2. Learn about the capillary networks associated with nephrons: Nephrons are surrounded by capillary networks that facilitate exchange of substances. These include the glomerular capillaries, peritubular capillaries, and the vasa recta.
3. Differentiate between the capillary networks: Glomerular capillaries are involved in filtration of blood within the Bowman's capsule. Peritubular capillaries surround the proximal and distal tubules and are involved in reabsorption and secretion. The vasa recta are specialized capillaries that surround the loop of Henle in juxtamedullary nephrons and play a role in maintaining the concentration gradient in the medulla.
4. Focus on juxtamedullary nephrons: These nephrons have long loops of Henle that extend deep into the medulla. The vasa recta are the capillaries that specifically surround these loops, aiding in the countercurrent exchange mechanism to concentrate urine.
5. Conclude the identification: Based on the anatomical and physiological roles, the network of capillaries surrounding the juxtamedullary nephrons is the vasa recta.