Vasa recta

Definition

The vasa recta are a series of capillaries in the kidney that run parallel to the loop of Henle. They play a critical role in maintaining the countercurrent exchange system, crucial for urine concentration and osmoregulation.

5 Must Know Facts For Your Next Test

1. The vasa recta are part of the renal medulla's blood supply.
2. They help maintain the osmotic gradient established by the loop of Henle.
3. Blood flow through the vasa recta is slow, which aids in efficient exchange of substances.
4. They prevent washout of solutes from the medullary interstitium, ensuring concentrated urine.
5. The descending and ascending limbs of the vasa recta have different permeability properties that facilitate countercurrent exchange.

Review Questions

• What role do the vasa recta play in kidney function?
• How do the vasa recta contribute to maintaining an osmotic gradient in the kidney?
• Why is slow blood flow through the vasa recta important?

Related terms

Loop of Henle: A section of the nephron that creates a concentration gradient in the medulla for water reabsorption.

Countercurrent Exchange: A system where fluids flow in opposite directions to maximize transfer rates.

Renal Medulla: The innermost part of the kidney containing structures like nephrons and collecting ducts involved in urine formation.