Renal sinus

Renal Sinus

The renal sinus is a complex anatomical structure found within the kidney. It is a cavity filled with fat and connective tissue, and contains the renal pelvis, renal calyces, blood vessels, nerves, and lymphatic vessels.

Anatomy

The renal sinus is located at the medial aspect of the kidney, where the renal hilum - the entrance to the kidney - is situated. It is surrounded by renal parenchyma, which is the functional tissue of the kidney involved in filtration and formation of urine.

The renal sinus is filled with perirenal fat, which provides cushioning and insulation for the structures within. The renal pelvis, a funnel-shaped structure that collects urine from the renal calyces and channels it into the ureter, is the most prominent structure within the renal sinus.

The renal sinus also contains the branches of the renal artery and renal vein, which supply blood to and drain blood from the kidney, respectively. The renal nerves, which control the function of the kidney, and lymphatic vessels, which remove waste products, are also found within the renal sinus.

Function

The primary function of the renal sinus is to house and protect the structures that are involved in the production, collection, and excretion of urine. The renal sinus also plays a role in the vascular supply of the kidney, as it contains the branches of the renal artery and vein.

Clinical significance

Diseases of the renal sinus are relatively rare but can be serious. These include renal sinus lipomatosis, a condition characterized by an excessive amount of fat in the renal sinus, and renal sinus cysts, which are fluid-filled sacs. Both conditions can lead to urinary obstruction and renal failure if not treated promptly.