The following are select vocabulary words to help you obtain a better understanding of the urinary system and its structures and functions.

1. Bowman capsule: cup-shaped capsule surrounding each glomerulus.
2. calyx (calix): cup-like collecting region of the renal pelvis.
3. catheter: tube for injecting or removing fluids.
4. cortex: outer region; the renal cortex is the outer region of the kidney.
5. creatine: a waste product of muscle metabolism; nitrogenous waste excreted in urine.
6. erythropoietin: a hormone secreted by the kidney to stimulate the production of red blood cells.
7. glomerulus: tiny ball of capillaries in cortex of kidney.
8. hilum: depression or pit in that part of an organ where blood vessels and nerves enter and leave.
9. kidney: one of the two bean-shaped organs located behind the abdominal cavity on either side of the backbone in the lumbar region.
10. medulla: inner region; the renal medulla is the inner region of the kidney.
11. nephron: the combination of glomerulus and renal tubule where filtration, reabsorption, and secretion take place in the kidney.
12. renal pelvis: central collecting region in the kidney.
13. renal tubule: microscopic tube in the kidney where urine is formed after filtration. In the renal tubule, the composition of urine is altered by the processes of reabsorption and secretion.
14. renin: an enzymatic hormone synthesized, stored, and secreted by the kidney; it raises blood pressure by influencing vasoconstriction.
15. trigone: triangular area in the bladder where the ureters enter and the urethra exits.
16. urea: major nitrogenous waste product excreted in urine.
17. ureter: tube leading from each kidney to the bladder.
18. urethra: tube leading from the bladder to the outside of the body.
19. uric acid: nitrogenous waste excreted in the urine.
20. urinary bladder: sac that holds urine.