prac 8

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  1. what % of mass in male is water
  2. what % of mass in females is water
  3. what % of mass in infants and children is water
  4. vol of water healthy young male
  5. intracellular fluid in male
    • 67%
    • 2/3
    • 28L
  6. extracellular fluid in male
    • 33%
    • 1/3
    • 14L
  7. plasma is part of _____ fluid
  8. plasma water of ECF
    • 1/4
    • 3L
  9. hormones and nerves play a part in
    control of volume and osmolality
  10. control of volume and osmolality is influenced by
    hormones and nerves
  11. how many types of subjects and what are they
    • 5
    • control
    • water
    • saline
    • urea
    • water+ADH
  12. what did the control subject consume?
    consumed no fluid during the class
  13. what did the water subject consume?
    drank 20mL of water/kg
  14. what did the saline subject consume?
    drank 7mL of 0.9% NaCl solution/kg
  15. what did the urea subject consume?
    drank 20mL of 1.8% urea solution/kg
  16. what did the the water + ADH subject consume
    drank 20mL of water/kg followed immediately by a dose of lysine vasopressin (ADH) by nasal instillation
  17. what was the subject procedure
    • empty bladder
    • weighed
    • consumed test solution over 15-20min period
    • urine was collected every 30mins
  18. urine vol was measured in
  19. osmolality was determined by
    freezing point depression
  20. osmolality results were expressed in
    mosm/kg H2O
  21. In class, asked to plot ___ & ___ as a function of ______
    • urine (mL/30min)
    • osmolality (mosm/kg)
    • time
  22. how long did the test run for
    150mins total
  23. how to calculate for osmolar excretion per 30mins?
    urine flow * osmolality
  24. what is the osmolality of 0.9% saline solution
  25. what is the osmolality of 1.8% urea solution
  26. is 0.9% saline isotonic and why
    yes. not net mvt of water
  27. is 1.8% urea isotonic and why
    no, it is hypotonic. urea moves down conc grad and brings urea and water into cell, causing it to swell
  28. if a cell is in a hypotonic solution, the cell will
  29. if a cell is in a hypertonic solution, the cell will
  30. is 0.9% saline iosmotic
  31. what is iosmotic
    having the same pressure
  32. does 0.9% saline go into ICF?
  33. why were subjects who drank 0.9% saline only given 7mL/kg instead of 20mL/kg?
    gives same ECF expansion as saline only goes into ECF
  34. what is effect of drinking 20ml/kg of water on urine flow rate and osmolality
    • diuresis
    • dramati incr in flow rate
    • decr in osmolality
  35. which solution produced similar urine flow rate to that of the water load and what was different
    • 1.8% urea
    • water has lower osmolality; urea has higher osmolality¬†
    • urea needs to be excreted in urine=active osmolality increasehehe
  36. why urea has greater flow rate than saline
    • urea is hypotonic = reduces ADH = not reabs from cd in kidneys
    • saline = isotonic = water doesnt enter cell = osmoreceptors not active
  37. did urea or saline have greater flow rate?
  38. which soln had greatest osmolar excretion + why?
    • urea
    • active urea excretion
  39. was diuresis due to vol expansion or dilution of osmolality or both? why?
    • both.
    • mainly water caused osmolality dilution¬†
    • smaller effect detected by osmoreceptors
  40. which osmoreceptors detect change and where are they located
    • supraoptic nucleus
    • paraventricular nucleus
    • in hypothalamus
  41. if osmoreceptor swells, effect is?
    ADH prodn switched off
  42. what is effect of ADH
    stops diuresis
  43. mechanism via water loading that causes diuresis are:
    • 1 stim of osmoreceptors = ADH inhibition
    • 2 incr in ECF vol = incr urine produced
  44. If water transfused into plasma, where does it go?
    • 1/3 ECF
    • 2/3 ICF
  45. If normal saline transfused into plasma, where does it go?
    all in ECF
  46. If urea transfused into plasma, where does it go?
    ECF and ICF
  47. If 5.5% mannitol transfused into plasma, where does it go?
    • mostly ECF
    • some may go into ICF
  48. If plasma transfused into plasma, where does it go?
    stays in vascular compartment
  49. If 10% albumin and 0.9%saline transfused into plasma, where does it go?
    • vascular compartment
    • may have slow turnover to ECF
  50. If blood transfused into plasma, where does it go?
    vascular compartment
  51. If 5.4% glucose transfused into plasma, where does it go?
    • initially into ECF
    • insulin required to enter ICF
  52. how to calculate osmolality
    osmolality of plasma * old vol/new vol
  53. calculating osmolality with changes in salt conc
    [(orig vol*orig osmolality)+(new vol added*osmolality in it)]/total vol
Card Set
prac 8
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