Urinary System
I. Organs
A. 2 Kidneys
1. Major excretory
organs
2. Filter blood
3. Eliminate nitrogenous waste
a. Creatinine – muscle metabolism, creatine breakdown
b. Urea – amino acid metabolism
c. Uric acid – nucleic acid metabolism
4. Elimination of excess ions, toxins, wastes, etc
5. Regulation of fluids
a. pH balance
1) Kidneys
2) Lungs [CO2]
3) Blood buffering systems
b. Salt/water balance
6. Produces
a. Renin
b. Erythropoietin
B. 2 Ureters
C. 1 Bladder
D. 1 Urethra
II. Nephron
A. 1 million / kidney
B. Functional units of kidney — filter blood to produce urine
C. Structure of a nephron
1. Renal Corpuscle
a. Bowman’s capsule
b. Glomerulus
2. Proximal convoluted tubule
3. Loop of Henle
4. Distal convoluted tubule
5. Collecting duct —- not part of nephron; numerous nephrons drain into a single
collecting duct
6. Peritubular capillaries – surround tubules of nephron
