LS2:Salt and Water Balance

  1. Excretory system have three processes in common
    • 1.Filtration: extracellular fluid is filtered to contain no cells or large cells
    • 2.Secretion: modifies the filtrate
    • 3.Reabsorption:concentrates the urine
  2. osmoconformers
    equilibrate their osmolarity with seawater
  3. Osmoregulators
    maintain osmolarities lower than seawater
  4. ammonotelic
    aquatic animalswho secrete NH3 through gills
  5. Terrestrial and other aquatic animals must convert NH3 to_____
    urea or uric acid.
  6. Urotelic
    • animals mostly excrete urea
    • -large water loss
  7. Urictelic
    • animals mostly excrete uric acid
    • -insoluble inwater
    • -little water loss
  8. Humans are ureotelic but also excrete:
    • • Uric acid—from metabolism of nucleic acids and caffeine
    • • Ammonia—regulates pH of extracellular fluid by buffering urine
  9. nephron
    the main fucntional unit of the kidney
  10. The rate of filtration is high in the glomerulus due to:
    • 1.High capillary pressure
    • 2.High permeability of glomerular capillaries and their podocytes
  11. Ureter
    a duct from the kidney that leads to the urinary bladder
  12. Urethra
    a tube for urine excretion, leading from the urinary bladder to outside the body
Card Set
LS2:Salt and Water Balance