Ascending limb

Ascending Limb

The ascending limb of the loop of Henle is a segment of the nephron in the kidney. It is a crucial component of the system that concentrates the urine and conserves water in the body. The ascending limb is divided into two sections: the thin ascending limb and the thick ascending limb.

Structure

The ascending limb of the loop of Henle is a part of the renal tubule and is located in the renal medulla. It follows the descending limb and leads to the distal convoluted tubule. The lower part of the ascending limb, which is adjacent to the descending limb, is thin, while the upper part is thick.

Function

The primary function of the ascending limb is to reabsorb sodium, chloride, and potassium ions from the urine. This process is crucial for the concentration of urine and the maintenance of the body's electrolyte balance. The thin ascending limb is permeable to ions but not to water, while the thick ascending limb actively transports ions out of the urine.

Clinical significance

Dysfunction of the ascending limb can lead to various kidney disorders, such as Bartter syndrome, which is characterized by a defect in the ion transporters in the thick ascending limb.

See also

• Descending limb
• Loop of Henle
• Nephron
• Kidney