Renal

Retroperitoneal organs

Organs that are located behind the peritoneal membranes; include the kidneys and ovaries.

Hilum

An indentation of the kidney on its medial face where the renal artery, renal vein, and ureters are located.

Peristaltic contractions

Muscle contractions of the ureters that help move urine from the kidneys to the bladder.

Renal artery

The large blood vessel that supplies blood to the kidneys.

Renal vein

The blood vessel that drains blood from the kidneys back into the inferior vena cava.

Juxtamedullary nephron

Nephrons that have longer loops of Henle and are involved in creating a concentration gradient in the medulla.

Cortex

The outer layer of kidney tissue where renal corpuscles, PCT, and DCT are found.

Medulla

The inner layer of kidney tissue consisting of renal pyramids and collecting ducts.

Nephron

The functional unit of the kidney responsible for filtering blood, forming urine, and performing reabsorption and secretion.

Bowman's Capsule

A spherical structure that encloses the glomerulus; involved in the initial filtration of blood.

Glomerulus

A network of fenestrated capillaries within Bowman's capsule where filtration of blood occurs.

Proximal convoluted tubule (PCT)

The portion of the nephron where significant reabsorption of water, glucose, and other substances occurs.

Loop of Henle

A U-shaped portion of the nephron involved in concentrating urine; consists of descending and ascending limbs.

Distal convoluted tubule (DCT)

The segment of the nephron that reabsorbs water and ions and secretes substances into the tubular fluid.

Collecting duct

The final segment of the nephron where water reabsorption occurs under the influence of ADH.

Internal urethral sphincter

Smooth muscle that controls the release of urine from the bladder.

ADH (Antidiuretic Hormone)

A hormone that increases water reabsorption in the collecting ducts of the kidney.

Renin-angiotensin-aldosterone system (RAAS)

A critical regulatory system for blood pressure and fluid balance involving the kidneys, hormones, and blood vessels.

Osmotic Gradient

A difference in concentration of solutes that drives the movement of water in the kidney.

Ureters

Muscular tubes that carry urine from the kidneys to the urinary bladder.

Minor calyces

Small ducts that collect urine from the renal pyramids and drain into the major calyces.

Vasorecta

Special peritubular capillaries that surround the loops of Henle in juxtamedullary nephrons.

Cortical nephrons

Nephrons primarily located in the cortex of the kidney, responsible for filtration and urine formation.

Podocytes

Specialized cells lining the visceral layer of Bowman's capsule that contribute to the filtration barrier.

Microvilli

Tiny hair-like projections on the apical surface of PCT cells that increase surface area for reabsorption.

Diuretics

Medications that increase urine production by inhibiting reabsorption of water and solutes in the kidneys.

Urethra

The duct that allows urine to exit the body from the bladder.

Efferent arteriole

The small blood vessel that carries blood away from the glomerulus to the peritubular capillaries.

Afferent arteriole

The small blood vessel that carries blood into the glomerulus.

Starling forces

Forces that determine the movement of fluid across capillary membranes, including hydrostatic and osmotic pressures.

Filtration

The process of separating waste and excess substances from the blood to form urine.