15.4 structure of mammalian kidney

Kidney

An organ that filters blood and produces urine.

Renal arteries

Blood vessels that supply oxygenated blood to the kidneys.

Ureters

Tubes that carry urine from the kidneys to the bladder.

Bladder

An organ that stores urine until it is excreted.

Urethra

The tube through which urine is expelled from the body.

Renal vein

A blood vessel that returns filtered blood from the kidneys to the heart.

Fibrous capsule

The outer membrane that protects the kidney.

Renal cortex

The outer region of the kidney containing Bowman's capsules, convoluted tubules, and blood vessels.

Renal medulla

The inner region of the kidney containing pyramids, loops of Henle, collecting ducts, and blood vessels.

Renal pelvis

A funnel-shaped cavity in the kidney that collects urine before it enters the ureters.

Nephrons

The functional units of the kidney, approximately 1 million per kidney, responsible for filtering blood and producing urine.

Bowman's capsule

A structure that surrounds the glomerulus and is where filtrate formation occurs.

Proximal convoluted tubule (PCT)

A nephron segment that reabsorbs water, glucose, and salts.

Loop of Henle

A nephron structure that creates a solute gradient to facilitate reabsorption.

Distal convoluted tubule (DCT)

A nephron segment that fine-tunes water balance under the influence of antidiuretic hormone (ADH).

Collecting duct

The final part of the nephron where water reabsorption occurs before urine is sent to the bladder.

Afferent arteriole

A blood vessel that supplies blood to the glomerulus.

Glomerulus

A network of capillaries that performs ultrafiltration, forcing fluid into Bowman's capsule.

Efferent arteriole

A blood vessel that carries blood away from the glomerulus.

Peritubular capillaries

Capillaries surrounding the proximal and distal convoluted tubules and the loop of Henle that absorb salts, glucose, and water.