urinary system

  1. functions of urinary system
    • nitrogenous wastes
    • toxins
    • drugs
    • regulate aspects of homeostasis (water balance, acid base balance, blood pressure, vit D activation)
  2. osmolarity
    overall water balance (water and sold content in the body remain constant)
  3. osmolarity of extra cellular fluid
    equals osmolarity of intracelllular fluid
  4. regulation of osmolarity is achieved by
    balancing intake and excretion of sodium with that of water
  5. electrolyte
    any chemical compound that produces ions when dissolved in water

    help maintain acid base balance and water balance
  6. acid-base balance
    • kidneys monitor and regulate levels of hydrogen ions and bicarbonate ions in the blood to control blood pH
    • H+ byproduct of dietary protein metabolism and accumulates in blood over time
  7. blood pressure
    • the stregnth of blood pushing against sides of blood vessels 
    • kidneys monitor blood pressure
  8. when blood pressure is too low
    kidneys produce renin, a hormone which restricts blood vessels and produces concentrated urine (allowing more water to remain in the blood)
  9. red blood cell production 
    erythropoietin aka EPO
    • EPO = hormone produced by kidneys to stimulate the production of red blood cells 
    • if blood doesn't have enough oxygen, EPo released
  10. activation of vitamin D
    • kidneys play role in turning vitamin D into active form Calciferol 
    • helps balance calcium and phosphorus levels by controlling the absorption of these minerals 
    • Parathyroid hormones (PTH) regulates calcium homeostasis and bone
  11. location of kidneys
    • T12 to L3
    • against dorsal body wall 
    • right lower than left 
    • adrenal gland on top of kidney
  12. organs of urinary system
    • kidneys
    • ureters
    • urinary bladder
    • urethra
  13. regions of kidney
    • renal cortex - (90% of blood flow) and all glomeruli found here
    • renal medulla - inside of cortex
    • renal pelvis - inner collecting tube, turns into ureter
  14. kidney structures
    • medullary pyraminds 
    • renal columns 
    • calyces (cup shaped funnel urine)
  15. nephrons
    • functional unit 
    • form urine
    • glomerulus 
    • renal tubule
  16. 1 million nephrons
    each kidney
  17. glomerular filtrate rate
    • one way to measure remaining kidney function 
    • process where kidneys filter blood, removing excess wastes in fluid 
    • 120ml/min

    glomerulus is primary site for filtration
  18. bowman's space
    • where glomerular filtrate collects
    • filtrate = H2O, glucose, salts, and urea
  19. review
    • blood comes to kidney from renal artery 
    • transferred to afferent arteriole
    • filtrated in glomerulus 
    • filtered carried out by efferent arteriole
  20. reabsorption
    2/3 nutrient reabsorption takes place in the proximal convoluted tubule
  21. loop of henle/descending loops
    • water reabsorbed passively (passive transport) 
    • descending loop is impermeable to Na
  22. ascending loop
    • reabsorbed via active transport (Na, K, Cl) 
    • secretion (and reabsorption) of NA and Cl is controlled by aldosterone
  23. collecting ducts
    principle cells
    • reabsorb Na and H2O 
    • secrete K
  24. creatinine
    chemical waste product in the blood that passes through the kidneys to be filtered and eliminated in urine
  25. water balance 
    antidiuretic hormone ADH
    regulates the osmotic pressure of body fluids by causing the kidneys to increase water reabsorption in the collecting ducts

    makes collecting ducts more permeable to water
  26. osmoreceptors
    • in hypothalamus 
    • detect changes in osmotic pressure 
    • dehydration causes osmotic pressure to increase
    • cells are called sensors
  27. hypothalamus
    • sends message to pituitary gland 
    • relsease ADH
    • hypothalamus acts as co ordinating center
    • PT gland is effector/regulator
  28. dehydrated
    • lowers osmotic pressure 
    • more concentrated urine
  29. over hydration
    • osmoticreceptors detect changes in osmotic pressure
    • causes osmotic pressure to decrease
  30. UTI
    more common in women because of shorter urethra
  31. kidney stones
    • dehydration is major risk for kidney stones
    • 80% kidney stones are calcium based
  32. calcitriol
    stimulates small intestines for protein synthesis
  33. detrusor muscles
    overactive bladder
Card Set
urinary system
ap 4 urinary system