Electrolytes Lecture

  1. Most water in the body is in the _______
    • cytosol (ICF)
    • -it's intracellular
  2. 99% of ECF is ________
  3. Why does the body need water?
    • Enzymatic reactions
    • Osmosis
    • Diffusion
    • maintain normal volume/composition of ICF/ECF
    • (isotonic environment)
  4. how do we gain water?
    • drinking
    • eating
    • byproduct of metabolism
  5. How do we lose water?
    • micturition
    • evaporation
    • respiration
    • defecation
  6. Primary source of water gain?
    Water loss?
    • Gain: digestive system
    • Loss: urinary system
  7. What are the most important electrolytes for maintaining electrolyte balance, and why is that?
    • Sodium, then chlorine (Cl-)
    • Cl- follows Na+ (charge)
    • H20 follows Na+
  8. What are electrolytes?
    ions released through dissociation of inorganic compounds
  9. why do we need electrolytes?
    • can conduct electrical current in solution
    • excitable membranes
  10. most common cation in ECF
  11. most common cation in ICF
  12. Most common anion in ECF
    chlorine, then bicarbonate
  13. most common anions in ICF
    phosphates and proteins
  14. what does our body tend to generate?  what does the body do about it?
    • acids
    • secrete buffers
  15. water accounts for what percentage of male body weight?
    • Male 60%
    • Female 50%
    • Newborn 75%
    • Elderly/obese 45%
  16. why do we lose water with age?
    • muscle holds water
    • loss of muscle -> loss of water
  17. what in our body holds a lot of our water?  What doesn't?
    • muscle does
    • fat doesn't (hydrophobic)
  18. what are the two major subdivisions of the ECF?  Which is most abundant?
    • ICF and blood plasma
    • ICF most abundant
  19. Minor subdivisions of ECF
    • lymph
    • CSF
    • Synovial fluid
    • serous fluids
    • aqueous humor
  20. what do the kidneys do to maintain acid/base balance?
    secrete H+ into urine, generate buffers that enter bloodstream
  21. What's the main solid that makes up the body?
  22. fluid compartments
    • ECF/ICF
    • behave as distinct entities
  23. inside of cell is slightly _____, outside slightly ______

  24. describe the difference between the osmotic concentration of the ICF and the ECF
    always striving to be equal (isotonic)

    if one becomes more concentrated, water will move via osmosis until they are equal again
  25. hormones regulating electrolyte balance and how (4)
    • adh : water
    • aldosterone: sodium, potassium, chlorine
    • anp/bnp: antagonistic
    • angiotensin II: reabsorbs sodium, secrete hydrogen
  26. adh target and function
    • collecting duct
    • inserts aquaporins

    • hypothalamus
    • stimulates thirst center
  27. what monitors the osmotic concentration of ECF?  what does this prompt?
    • osmoreceptors in the hypothalamus
    • -location of BBB
    • causes secretion of ADH and angiotensin II
    • stimulates thirst center
  28. if you are sweating, is your ECF hyper or hypo tonic?
  29. If you drink a lot of pure water, what happens to your ECF?
    becomes hypotonic
  30. what stimulates the release of aldosterone?
    • concentrated ECF (hypertonic)
    • rising potassium levels: hyperpolaria
  31. What disease targets adrenal glands, inhibiting production of aldosterone?  what are the results of this disease?
    • Addison's disease
    • chronic low blood pressure
  32. when body loses water, plasma volume increases/decreases?  electrolyte levels rise/fall?  when does this occur?
    • decrease
    • rise
    • during exercise
  33. what force pushes water out of plasma and into the ICF?
    net hydrostatic pressure
  34. what force draws water out of ICF and into plasma?
    Net colloid osmotic pressure
  35. edema occurs when there is excess fluid in the ____
  36. why do you lose more water via respiration on cold days?
    BMR raises
  37. rapid water movements between ECF and ICF
    fluid shifts
  38. severe water loss
  39. what happens when water is gained but electrolytes aren't?
    ECF volume increases, becomes hypotonic to ICF, fluid shifts to ICF, cells swell up and aren't as excitable
  40. water excess
  41. excessive production of what hormone can lead to overhydration?
    ADH (tumor)
  42. what disorders/diseases may cause overhydration?
    • chronic renal failure: glomeruonephritis
    • heart failure -> edema
    • cirrhosis: lowers BCOP -> excess filtration, not enough reabsorption
    • all lead to inability to remove water in urine
Card Set
Electrolytes Lecture
Electrolyte lecture from A&P 233