24 Flashcards
boy water content for baby male female
80
60
50
what part of body absorbs the most water
small intestine
is there protein in ISF
no think of the banana tree on island analogy
is there protein in intracellular fluid
yes
protein anions
what are the major solutes that contribute to osmolality
electrolytes:Na Cl
non electrolytes:glucose urea
whats the mode of action of penicillin
prevent cell wall biosynthesis so cells explode
what can cause osmotic diarrhoea
lactase deficiency
what has a greater osmotic power electrolytes or non elxctrolyes
electrolytes
which is more commonly used osmolarity or osmolality and why
lality because its based on mass not volume which can change with changes in T and P.
normal plasma osmolality
300 mOsm/Kg
main solute in blood
albumin
what three mechanisms control sodium water regulation
CNS
hormones
kidneys
how does CNS regulate Na and sodium concentrations
using SFO and OVLT in hypothalamus
main trigger for thirst is
osmolality
how do hormones regulate plasma volume
ADH=vasopresin
in CD
ANP
angiotensin
molecular target of ADH
aquaporin transcription
how do hormones regulate plasma osmolality
aldosterone which acts on eNAC and nak pumps
released from adrenal cortex when too little Na or too much Kplus
results in overactivatiomn of enac so takes up more sodium
how do ANP work
atrial natriuretic peptide
release from cardiac atria when high blood volume
increases Na secretion.
where is most water absorbed int eh kidney
80% proximal tubule
normal urine osmolality
500-800 mOsm per kilo
normal random urine osmolality
50-1400 mOsm per kilo
normal urine osmolality after 12-14 hours restriction
more than 800 mosmoles pet kilo
water depirivation test
urine osmolality after 12-14 hours restriction
water intoxication
too much water drank too fast or ecstasy induced hyponatremia
