Papillary duct

Papillary Duct

Diagram of a nephron, the functional unit of the kidney. The papillary duct is labeled as the "collecting duct".

The Papillary Duct (also known as Duct of Bellini or Collecting Duct) is a part of the urinary system in the human body. It is the final component of the nephron, the functional unit of the kidney. The papillary duct plays a crucial role in the concentration and final modification of urine.

Structure

The papillary duct is a tube-like structure that extends from the renal papilla to the minor calyx. It is formed by the convergence of several collecting ducts that drain into it. The walls of the papillary duct are lined with simple columnar epithelium, which aids in the reabsorption and secretion processes.

Function

The primary function of the papillary duct is to carry urine from the collecting ducts to the minor calyx. During this journey, the urine undergoes final modifications. The duct's epithelial cells have the ability to reabsorb water and secrete potassium ions, thereby helping to maintain the body's electrolyte balance.

Clinical Significance

Abnormalities or damage to the papillary duct can lead to various kidney disorders. For instance, the formation of kidney stones often begins in the papillary duct. In addition, certain types of kidney cancer can originate from the cells lining the papillary duct.

See Also

• Kidney
• Nephron
• Urinary system
• Renal papilla
• Minor calyx