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 cortex-like 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 for 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)

Angiotensin II formed in blood Peripheral resistance Falling systemic blood pressure volume Reduced filtrate volume or solute content in renal tubules JG cells of kidneys (+) (+) = stimulates Renin-angiotension system Neural regulation (sympathetic nervous system effects) Effects of ADH release Renin Release Leads to Angiotensin II formed in blood Systemic arterioles Vasoconstriction Peripheral resistance Adrenal cortex Aldosterone Kidney tubules Na+ reabsorption (and H2O absorption) Blood volume Rising blood pressure Causes Results in Secretes Targets Releases Inhibits baroreceptors in blood vessels Sympathetic nervous system Hypothalamic osmoreceptors Posterior pituitary ADH (antidiuretic hormone) Collecting ducts of kidneys H2O reabsorption KEY:

Urinary System Video http://video.about.com/surgery/Kidney-Transplant.htm http://animal.discovery.com/videos/river-monsters-fish-swims-up-urine-stream.html http://animal.discovery.com/videos/weird-true-freaky-fish-attacks-mans-urethra.html

Kidney Transplant Video http://www.orlive.com/sentara-profile/videos/living-donor-kidney-transplant-surgery1 https://www.youtube.com/watch?v=ou8CC4XN9wk