Juxtamedullary nephrons

Definition

Juxtamedullary nephrons are specialized structures within the kidney that play a crucial role in concentrating urine. They have long loops of Henle that extend deep into the medulla.

5 Must Know Facts For Your Next Test

1. Juxtamedullary nephrons constitute about 15% of all nephrons in the human kidney.
2. They are essential for producing concentrated urine, which helps conserve water in the body.
3. These nephrons have longer loops of Henle compared to cortical nephrons, reaching deep into the renal medulla.
4. The vasa recta, a series of straight capillaries in the medulla, is closely associated with juxtamedullary nephrons and plays a key role in maintaining the osmotic gradient.
5. Juxtamedullary nephrons enable efficient reabsorption of water and solutes due to their unique anatomical structure.

Review Questions

• What percentage of all nephrons do juxtamedullary nephrons constitute?
• How do juxtamedullary nephrons contribute to water conservation in the body?
• What is the significance of the long loops of Henle in juxtamedullary nephrons?

Related terms

Cortical Nephron: A type of nephron located primarily in the renal cortex with shorter loops of Henle.

Loop of Henle:

A U-shaped part of the nephron essential for concentrating urine.

Vasa Recta: Capillary networks that supply blood to the renal medulla and maintain an osmotic gradient.