Physiology - Renal endocrinology, osmolarity and volume Flashcards
what happens to osmolarity when ECF is lost
a.increase
b.decrease
a.increase
water moves from cell to solution and cell shrinks
what happens to osmolarity when ECF is gained
a.increase
b.decrease
b.decrease
water moves from outside fluid into cell and cell swells
what effect does an ECF osmolarity of more than 290mOsm have on ADH secretion
a. increase
b.decrease
a. increase
>290 mOsm is hypertonic
normal is 280 mOsm
when the ECF is hypertonic to the cell aquaporin channels in hypothalamic neurones (osmo receptors) allow water to …………. the cell via osmosis
a. enter
b.exit
b.exit
in conditions when ECF osmolarity is increased , after water leaves osmo receptors in the hypothalamus via aquaporin channels which channels open
a.potassium
b.stretch sensitive
c.pacinian
b.stretch sensitive
opening of stretch sensitive channels in response to shrinking of osmoreceptors in hypertonic conditions allows entrance of which to substances to the nerve
a. sodium and pottasium
b.sodium and calcium
c.calcium and pottassium
d.sodium and water
b.sodium and calcium
wave of depolarisation and action potential generated
where does the nerve impulse generated by stretch sensitive channels in osmoreceptor hypothalamic nerves (due to hypertonic conditions) travel to
a. supraoptic and paraventricular neurones
b. anterior and posterior lobes of pituitary
c.adrenal medulla and adrenal cortex
a. supraoptic and paraventricular neurones
in which lobe of the pituitary gland do supraoptic and paraventricular nodules release ADH
a.anterior
b.posterior
b.posterior
where does ADH increase water reabsorption
a.proximal convuluted tubule
b.distal convuluted tubule
c.loop of henle
b.distal convuluted tubule
and collecting duct
ADH causes water to move from the ………….. to the………….. via the distal convuluted tubule
a.blood to the flitrate
b.filtrate to the blood
b.filtrate to the blood
increased water reabsorption dilutes the plasma
ADH causes water to move from the ………….. to the………….. via the distal convuluted tubule
a.blood to the flitrate
b.filtrate to the blood
b.filtrate to the blood
increased water reabsorption dilutes the plasma
Under the influence of ADH which type of channels are inserted into the wall of the distal convuluted tubule
a.sodium
b.pottasium
c. stretch dependent
d.aquaporins
d.aquaporins
water channels
water moves from filtrate to blood and plasma is diluted
In hypotonic conditions ( ECF osmolarity less than 280mOsm) aquaporin channels in the hypothalamic neurones allow water to …………. the cell via osmosis
a.enter
b.exit
a.enter
what happens to stretch channels when osmoreceptors expand in hypotonic conditions
a.activated
b.deactivated
b.deactivated
what happens to stretch channels when osmoreceptors expand in hypotonic conditions
a.activated
b.deactivated
b.deactivated
when stretch channels are inactivated by hypotonic conditions what happens to ADH release
a.increase
b.decrease
b.decrease
less sodium and calcium entry, no AP
supraoptic and paraventricular nerves not activated
decreased ADH release from post pituitary
reduced H2O reabsorption at collecting duct
increased ECF osmolarity
dilute urine and large volume
which two factors control ADH secretion
a.ECF osmolarity and blood pressure
b.ECF osmolarity and blood sodium levels
c.ECF osmolarity and jvp
a.ECF osmolarity and blood pressure
where are baroreceptors that sense pressure in the form of stretch on blood vessel wall found
a.hypothalamus and pituitary
b.supraoptic and paraventricular neurons
c. osmoreceptors in hypothalamus
d.carotid sinus and aortic arch
d,carotid sinus and aortic arch
with each heart beat what happens to baroreceptors
a.activate
b.deactivate
a.activate
ion channeles open calcium and sodium enter and nerve cell (baroreceptor) depolarises
AP transmitted to hypothalamus
where do baroreceptors transmit the action potential to when they depolarise after undergoing stretch on the vessel wall
a. anterior pituitary
b. posterior pituitary
c. hypothalamus
d. supraoptic and paraventricular nerves
c. hypothalamus
normal BP inhibits SON and PVN release of ADH
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in a state of reduced blood pressure what happens to ADH release
a.increase
b.decrease
a.increase
baroreceptor neurons fire less
so SON and PVN not inhibited , more active
increased ADH released
more water reabsorped
increased BP
what effect does normal blood pressure have on SON and PVN transmitted ADH release
a. increase
b.decrease
b.decrease
AP transmitted to hypothalamus when baroreceptors activated by each heart beat , if at normal rate it inhibtis the release of ADH from the SON and PVN
which of these is the correct set of events.that trigger the release of aldosterone from the zona glomerulosa of the adrenal cortex
a.increased plasma K+, increased angiotensin 2 , decreased plasma pH, decreased atrial stretch , decreased blood pressure
b. decreased plasma k+, decreased angiotensin 2 , increased plasma pH, increased atrial stretch, increased blood pressure
a.increased plasma K+, increased angiotensin 2 , decreased plasma pH, decreased atrial stretch , decreased blood pressure