Urinary System Functions of the Urinary System Primary

Urinary System

Functions of the Urinary System • Primary: Elimination of waste products: – Nitrogenous waste – Toxins – Drugs • Secondary: Regulate homeostasis – Water balance – Electrolytes – Acid-base balance – Blood pressure – RBC formation

Organs of Urinary System • • Kidneys Ureters Urinary Bladder Urethra

Location of Kidneys

Kidney Regions Renal cortex—outer region Renal medulla—inside the cortex Renal pelvis—inner collecting tube

Kidney Structures • Renal or medullary pyramids—triangular regions of tissue in the medulla • Renal columns— extensions of cortexlike material inward that separate the pyramids • Calyces—cup-shaped structures that funnel urine towards the renal pelvis

Kidney Functions • One-quarter of the total blood supply of the body passes through the kidneys each minute • Renal artery provides each kidney with arterial blood supply • Renal artery divides into segmental arteries interlobar arteries arcuate arteries cortical radiate arteries

Nephrons • The structural and functional units of the kidneys • Responsible forming urine • Main structures of the nephrons – Glomerulus – Renal tubule

Nephrons • Glomerulus – Knot of capillaries – Capillaries are covered with podocytes from the renal tubule – Glomerulus sits within a glomerular (Bowman’s) capsule (the first part of the renal tubule)

Nephron • Renal tubule extends from glomerular capsule and ends at the collecting duct – Glomerular (Bowman’s) capsule – Proximal convoluted tubule (PCT) – Loop of Henle – Distal convoluted tubule (DCT)

Falling systemic blood pressure volume (+) Reduced filtrate volume or solute content in renal tubules Inhibits baroreceptors in blood vessels Hypothalamic osmoreceptors (+) (+) JG cells of kidneys Sympathetic nervous system Posterior pituitary Releases (+) ADH (antidiuretic hormone) Release Systemic arterioles Causes Renin (+) Collecting ducts of kidneys Vasoconstriction Leads to Results in Causes Peripheral resistance Angiotensin II formed in blood H 2 O reabsorption (+) (+) Systemic arterioles Adrenal cortex Causes Vasoconstriction Secretes Aldosterone Results in Peripheral resistance Targets Kidney tubules Causes Na+ reabsorption (and H 2 O absorption) Results in Blood volume KEY: (+) = stimulates Rising blood pressure Renin-angiotension system Neural regulation (sympathetic nervous system effects) Effects of ADH release

• Urinary System Video • http: //www. youtube. com/watch? v=d. Upa. Haw FLUk • http: //video. about. com/surgery/Kidney. Transplant. htm • http: //animal. discovery. com/videos/rivermonsters-fish-swims-up-urine-stream. html • http: //animal. discovery. com/videos/weirdtrue-freaky-fish-attacks-mans-urethra. html

Kidney Transplant Video • http: //www. orlive. com/sentaraprofile/videos/living-donor-kidney-transplantsurgery 1 • https: //www. youtube. com/watch? v=ou 8 CC 4 X N 9 wk