1. Urinary System  Kidneys: removes wastes and regulates blood volume and composition  Ureters: tubes that connect the kidneys to the bladder  Bladder: A thin muscled sac with rugae that stores urine until it can be voided  Urethra: a tube that carries urine from the bladder to the exterior of the body

2. Wastes  Nitrogenous wastes: 50% is urea which is a product of protein catabolism that produces ammonia that the liver then changes into urea  Uric acid and creatinine are also NW not as dangerous  Blood urea nitrogen (BUN): elevated levels of BUN can cause uremia which leads to comas and death

3. Excretion  The process of separating wastes from body fluids and eliminating them  What four systems play a roll in excretion –A–A–A–A –B–B–B–B –C–C–C–C –D–D–D–D