Biology – Homeostasis in mammals | e-Consult

The human kidney is a complex organ with a highly organized structure designed for efficient filtration and waste removal from the blood. Here's a breakdown of the key components:

• Fibrous Capsule: This is the outermost layer of the kidney, a tough, dense connective tissue layer. It provides protection and maintains the kidney's shape. It also helps to anchor the kidney in place.
• Cortex: This is the outer region of the kidney, just beneath the fibrous capsule. It contains the renal corpuscles (glomeruli and Bowman's capsules) and convoluted tubules (proximal and distal convoluted tubules). The cortex is responsible for the initial filtration of blood.
• Medulla: This is the inner region of the kidney, consisting of cone-shaped structures called renal pyramids. The base of each pyramid faces the renal pelvis, and the apex points towards the inner cavity of the kidney. The medulla contains the loops of Henle and collecting ducts, crucial for concentrating urine.
• Renal Pelvis: This is a funnel-shaped cavity located in the center of the kidney. The renal pyramids empty into the renal pelvis. It collects urine from the collecting ducts and channels it into the ureter.
• Ureter: A tube that extends from the renal pelvis to the urinary bladder. It transports urine from the kidney to the bladder via peristaltic contractions.
• Branches of the Renal Artery: The renal artery enters the kidney and branches into smaller arteries that run through the cortex, supplying blood to the nephrons. These branches deliver oxygen and nutrients necessary for filtration.
• Renal Vein: The renal vein collects blood from the nephrons after it has been filtered. It carries the filtered blood away from the kidney and back to the heart. The renal vein typically follows the path of the renal artery.

Function Summary: The fibrous capsule provides protection. The cortex houses the initial filtration units. The medulla contains structures essential for urine concentration. The renal pelvis collects urine. The ureter transports urine. The renal artery supplies blood, and the renal vein returns filtered blood.