Medulla

Definition

The medulla is the innermost region of the kidney, responsible for concentrating urine and maintaining water and salt balance in the body. It contains structures like the loop of Henle and collecting ducts that are crucial for osmoregulation.

5 Must Know Facts For Your Next Test

1. The medulla consists of renal pyramids which contain nephrons responsible for filtering blood.
2. It plays a key role in reabsorbing water and sodium back into the bloodstream to concentrate urine.
3. The loop of Henle, located within the medulla, establishes a concentration gradient essential for water reabsorption.
4. Collecting ducts in the medulla transport urine from nephrons to the renal pelvis.
5. Increased antidiuretic hormone (ADH) levels enhance water reabsorption in the medulla's collecting ducts.

Review Questions

• What structures within the kidney's medulla are crucial for concentrating urine?
• How does the loop of Henle contribute to osmoregulation?
• What role does ADH play in the function of the medulla?

Related terms

Loop of Henle: A U-shaped structure in nephrons that helps establish a concentration gradient for water reabsorption.

Collecting Ducts: Tubes that collect urine from nephrons and transport it to the renal pelvis.

Antidiuretic Hormone (ADH): A hormone that increases water reabsorption in kidney's collecting ducts to concentrate urine.