Renal Physiology Flashcards
Daily and Minute GFR?
daily - 180L
minute - 120ml/min
where do circulating catecholamines constrict?
primarily afferent
what MBP results in filtration decrease and when do it cease?
60mmHg
50mmHg
auto regulatory range in man?
60-130mmHg
renal plasma threshold for glucose?
beyond 10mmoles/l
reabsorption of Na ions?
most abundant in ECF and 99.5% reabsorbed
active transport on basolateral surfaces
creates an osmotic force drawing water out
tubule permeability to urea?
only moderately permeable to urea so that only 50% is reabsorbed and the remainder stays in the tubule
most important point about the movement of Na?
it is the active transport of Na that establishes the gradients down which other ions, water and solutes pass passively
why is tubular secretion important?
important for substances that are protein bound
normal K ECF level?
around 4mmoles/l
max concentration of urine produced by kidney?
min obligatory water loss?
1200-1400mOsmoles/l
500mls/day
how are kidneys able to produce varying concentrations of urine?
loops of hence of juxtamedullary nephrons act as counter-current multipliers
where is ADH synthesised?
half-life?
supraoptic and paraventricular nuclei of the hypothalamus
10 mins
normal plasma osmolality?
280-290mOsm/kg H20
distribution of body water?
plasma 3L
Interstital 11l
= 14L ECF
ICF 28L
total = 42L. 60 40 20
