PHSI 208 Lecture Notes - Lecture 1: Peritubular Capillaries, Juxtaglomerular Apparatus, Afferent Arterioles
Document Summary
Functions of the kidneys: the most important function of the kidneys is homeostatic regulation of water and ion content of the blood (salt-water balance or fluid-electrolyte balance). Na+ is the main controller of extracellular fluid volume: homeostatic regulation of ph: if plasma becomes acidic, kidneys remove h+ and conserve hco3-, and vice versa, excretion of wastes: by-products of metabolism, drugs, hormones. Urobilinogen gives urine its yellow colour: production of hormones: erythropoietin (increases production of rbcs) and renin (helps to maintain blood pressure and na+ balance) lead to production of hormones involved in na+ balance and blood pressure homeostasis. Reserve capacity: 1 in every 1000 babies are born with 1 kidney, and can lose of kidney function before affecting homeostasis. To ensure blood is constantly monitored and filtered, kidneys receive 20-25% of cardiac output. The kidneys are located retroperitoneally (at the back of peritoneal/abnominal cavity) at the level of the lower ribs.
