Urinary System Flashcards

Flashcards covering key vocabulary and concepts related to the urinary system.

Urinary System Structure

Organs including the kidneys, ureters, bladder, and urethra

Urinary System Function

Maintains homeostasis of blood volume, pressure, pH, and electrolytes; reabsorbs glucose; excretes wastes; releases hormones like renin and EPO

Kidneys

Bean-shaped organs located just above the waist in the retroperitoneal space

Ureter

Tube that originates near the hilum of each kidney and travels to the base of the bladder

Urethra

Allows urine to be excreted from the bladder

Cortex

Kidney layer responsible for filtration to form urine

Medulla

Kidney layer that collects and excretes urine

Renal Pyramids

Conical subdivisions within the medulla containing the kidney’s secreting apparatus and tubules

Renal Columns

Lines of blood vessels and fibrous material which anchor the cortex

Renal Papilla

Medullary pyramids empty urine into minor and major calyces

Ureters

Transports urine from the renal pelvis of the kidneys to the bladder using peristaltic waves, hydrostatic pressure, and gravity

Urinary Bladder

Hollow, distensible muscular organ with a capacity of 700-800mL

Urethra

Tube from the internal urethral orifice in the bladder floor to the exterior

Nephron

Functional unit of the kidney consisting of blood vessels and tubules that collect filtrate from blood and turn it into urine

Glomerulus

Ball-shaped capillary network receiving blood from an afferent arteriole

Glomerular Capsule (Bowman’s Capsule)

Double-walled epithelial cup that surrounds the glomerular capillaries

Podocytes

Modified simple squamous epithelial cells that wrap around the endothelial cells of the glomerular capillaries

Filtration Membrane

Acts as a filtration (dialysis) membrane with fenestrations (pores)

Renal Tubule Sections

Three main sections: proximal convoluted tubule (PCT), loop of Henle, and distal convoluted tubule (DCT)

Collecting Duct

Empties into a single collecting duct from distal convoluted tubules of several nephrons

Descending Limb of the Loop of Henle

Descends into the renal medulla

Nephron Types

Two populations: cortical and juxtamedullary

Cortical Nephrons

Make up about 80–85% of the nephrons; short loops of Henle that penetrate only a small way into the medulla

Juxtamedullary Nephrons

15–20% of the nephrons; renal corpuscles lie deep in the cortex, close to the medulla, and have long loops of Henle