Excretory system removes waste materials from body fluids for homeostasis. Eliminates metabolic waste and drains body components in liquid and gaseous states. Most waste products leave body as urine in mammals and amniotes
Kidney stones form when solid material develops in urinary tract. Most common types are calcium oxalate (70-80%), struvite (10-15%), and uric acid (5-10%). Stones can form in kidney, ureter, or bladder
Calcium oxalate (CaC2O4) is a calcium salt of oxalic acid. Forms hydrates CaC2O4·nH2O, where n varies from 1 to 3. Anhydrous and hydrated forms are colorless or white
Oxalate (C2O2−4) is a colorless anion that occurs naturally in foods. It forms salts and esters, including sodium oxalate (Na2C2O4). Oxalic acid completely converts to oxalate at neutral pH
Ureters are tubes that transport urine from kidneys to bladder. Adult ureters measure 20-30 cm in length and 3-4 mm in diameter. They are lined with urothelial cells and have extra smooth muscle layer. Urine travels through ureters using peristalsis
Calcium phosphate contains calcium ions (Ca2+) with inorganic phosphate anions. White solids found in bone mineral and tooth enamel. Exists in colloidal form in milk bound to casein protein