Physiology - Renal endocrinology, osmolarity and volume Flashcards

1
Q

what happens to osmolarity when ECF is lost

a.increase
b.decrease

A

a.increase
water moves from cell to solution and cell shrinks

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2
Q

what happens to osmolarity when ECF is gained

a.increase
b.decrease

A

b.decrease
water moves from outside fluid into cell and cell swells

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3
Q

what effect does an ECF osmolarity of more than 290mOsm have on ADH secretion

a. increase
b.decrease

A

a. increase
>290 mOsm is hypertonic
normal is 280 mOsm

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4
Q

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

A

b.exit

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5
Q

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

A

b.stretch sensitive

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6
Q

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

A

b.sodium and calcium

wave of depolarisation and action potential generated

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7
Q

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

a. supraoptic and paraventricular neurones

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8
Q

in which lobe of the pituitary gland do supraoptic and paraventricular nodules release ADH

a.anterior
b.posterior

A

b.posterior

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9
Q

where does ADH increase water reabsorption

a.proximal convuluted tubule
b.distal convuluted tubule
c.loop of henle

A

b.distal convuluted tubule
and collecting duct

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10
Q

ADH causes water to move from the ………….. to the………….. via the distal convuluted tubule

a.blood to the flitrate
b.filtrate to the blood

A

b.filtrate to the blood

increased water reabsorption dilutes the plasma

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11
Q

ADH causes water to move from the ………….. to the………….. via the distal convuluted tubule

a.blood to the flitrate
b.filtrate to the blood

A

b.filtrate to the blood

increased water reabsorption dilutes the plasma

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12
Q

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

A

d.aquaporins

water channels

water moves from filtrate to blood and plasma is diluted

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13
Q

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

a.enter

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14
Q

what happens to stretch channels when osmoreceptors expand in hypotonic conditions

a.activated
b.deactivated

A

b.deactivated

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14
Q

what happens to stretch channels when osmoreceptors expand in hypotonic conditions

a.activated
b.deactivated

A

b.deactivated

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15
Q

when stretch channels are inactivated by hypotonic conditions what happens to ADH release

a.increase
b.decrease

A

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

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16
Q

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

a.ECF osmolarity and blood pressure

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17
Q

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

A

d,carotid sinus and aortic arch

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18
Q

with each heart beat what happens to baroreceptors

a.activate
b.deactivate

A

a.activate

ion channeles open calcium and sodium enter and nerve cell (baroreceptor) depolarises
AP transmitted to hypothalamus

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19
Q

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

A

c. hypothalamus

normal BP inhibits SON and PVN release of ADH

r

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20
Q

in a state of reduced blood pressure what happens to ADH release

a.increase
b.decrease

A

a.increase

baroreceptor neurons fire less
so SON and PVN not inhibited , more active
increased ADH released
more water reabsorped
increased BP

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21
Q

what effect does normal blood pressure have on SON and PVN transmitted ADH release

a. increase
b.decrease

A

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

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22
Q

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

a.increased plasma K+, increased angiotensin 2 , decreased plasma pH, decreased atrial stretch , decreased blood pressure

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23
Q

what is the main trigger of aldosterone secretion

a.increase in blood pottasium
b.increased blood pressure
c.increased blood sodium
c.decreased blood pottasium

A

a.increase in blood pottasium

24
Q

what is the effect of aldosterone

a.increased sodium and water reabsorption , increased potassium and H+ secretion

b.decreased sodium and water reabsorption, increased pottasium and H+ secretion

A

a.increased sodium and water reabsorption , increased potassium and H+ secretion

25
Q

aldosterone stimulates expression of which pump

a.sodium pottasium
b.sodium
c. H+ / potassium

A

a.sodium pottasium

26
Q

where is most of pottasium reabsorbed
a.collecting duct
b.distal tubule
c.proximal convuluted tubule
d. loop of henle

A

c.proximal convuluted tubule

27
Q

which transporter is responsible for absorption of potassium at the ascending loop of henle

a.potassium channel
b.sodium potassium pump
c. H+/ potassium pump
d.sodium, potassium ,chloride pump

A

d.sodium, potassium ,chloride pump

28
Q

which parts of the kidney tubule contain the sodiu potassium pumps of which expression is increased when aldosterone is secreted

a.distal convulutued tubule and collecting duct
b.distal and proximal convoluted tubules
c.ascending loop of henle and proximal convuluted tubule

A

a.distal convulutued tubule and collecting duct

29
Q

hyperaldosteronism

A

overproduction of aldosterone by the adrenal glands

30
Q

Hyperaldosteronism as a result of an aldosterone producing tumour eg conns syndrome is referred to as

a. primary hyperaldosteronism
b.secondary hyperaldosteronism
c. basic hyperaldosteronism

A

. primary hyperaldosteronism

31
Q

Hyperaldosteronism as a result of overactivity of RAAS is known as
a. primary hyperaldosteronism
b.secondary hyperaldosteronism
c. basic hyperaldosteronism

A

b.secondary hyperaldosteronism

32
Q

which of these signs are diagnostic clues for hyperaldosteronism

a.hypokalaemia, arterial hypertension

b.hyperkalaemia , arterial hypotension

c.hyponatraemia, arterial hypertension

d.hypernatraemia, arterial hypotension

A

a.hypokalaemia, arterial hypertension

33
Q

what is hyperaldosteronism treated with

A

aldosterone antagonists
surgery

34
Q

what is the role of renin in RAAS

a.converts angiotensin 1 to angiotensin 2
b.converts angiotensinogen to angiotensin 1
c.converts angiotensinogen to angiotensin 2
d.converts angiotensin 2 to aldosterone

A

b.converts angiotensinogen to angiotensin 1

35
Q

what does angiotensin 2 stimulate the brain to release

a.CRH
b. ACTH
c.ADH
d.cortisol

A

c.ADH

acts on kidneys
inceases water resorption
along with action of aldosterone on sodium potassium pump expression in DCT and ducts
increases blood volume
increased blood pressure and cardiac output

36
Q

what effect does increased sympathetic nerve activity to jg cells have on renin release

a.increase
b.decrease

A

a.increase

37
Q

increased water resorption and so blood volume as a result of RAAS has what effect on ECF osmolarity

a.increase
b.decrease

A

b.decrease

do not want to absorb more water to further dilute blood

hypothalamus overwrites effects of angiotensin 2 on ADH release

decreased ADH release so decreased water resorption

38
Q

where are the macula densa cells found

a.DCT
b.surrounding afferent arteriole
c.surrounding efferent arteriole

A

a.DCT

39
Q

low sodium in filtrate results in reduced sodium being resorbed what substance is produced and passed to the neighbouring jg cells from the macula densa as a result of this being detected

a.cAMP
b.IP3
c.protaglandin E

A

c.protaglandin E

jg cells release renin into afferent arteriole

40
Q

sympathetic nerves acting on the afferent arteriole activate which receptor on jg cells in low sodium conditions

a.b1
b.b2
c.a1
d.a2

A

a.b1

results in production of cAMP and so renin

41
Q

activation of B1 adrenergic receptors on the JG cells leads to production of which substance in the jgc surrounding the afferent arteriole

a.cAMP
b.IP3
c.PGE

A

a.cAMP

42
Q

when blood pressure subsequently increases in the afferent arteriole due to renin release which channels in the jgc are activated \

a.potassium
b.sodium
c.stretch activated

A

c.stretch activated

down regulate cAMP so renin reduced and BP decreases

43
Q

where are the cells found that release ANP in response to increased blood volume

a.hypothalamus
b.ventricles
c.right atrium
d. left atrium

A

c.right atrium

atrial natiuretic peptide released by atrial monocytes in response to atrial distention

44
Q

what effect does ANP release have on renin release

a.stimulates
b.inhibits

A

b.inhibits

so decreases ang 2 and ald

45
Q

what effect does ANP have on glomerular filtration rate

a.increase
b.decrease

A

a.increase

46
Q

what effect does ANP have on the sodium transporter in the loop of henle

a.increase activity
b.decrease activity

A

b.decrease activity

less sodium reabsorbed
less water following

47
Q

what effect does ANP have on systemic circulation directly and via reduced angiotensin 2

a.vasodilation
b.vasoconstriction

A

a.vasodilation

48
Q

what serves as a natural counter regulatory mechanism to RAAS

A

Atrial natriuretic peptide

49
Q

when is thirst activated

a. when blood osmalirity increases
b. when blood osmolarity decreases

A

a. when blood osmalirity increases

50
Q

when is the thirst impulse surpressed after drinking

a.immediately
b.when osmolarity is normalised

A

a.immediately

51
Q

what is higher the osmotic threshold for activation of thirst or for ADH release

a.thirst
b.ADH release

A

a.thirst

52
Q

where does the thirst sensation originate

a. anterior pituitary
b.posterior pituitary
c. anterior cingulate cortex
d.hypothalamus
e.posterior cingulate cortex

A

c. anterior cingulate cortex

53
Q

which 3 factors activate the thirst sensation in the anterior cingulate cortex

A

high plasma osmolarity
input from brain - anticipation of food
input from body- sensing food in mouth

54
Q

what is the stimulus in kidney homeostasis

A

imbalance in blood volume / pressure and change in osmolarity

55
Q

what is the sensor in kidney homeostasis

A

stretch sensors , sodium transporters

56
Q

what is the control centre in kidney homeostasis

A

hypothalamus, JG apparatus, heart

57
Q

what is the effector in kidney homeostasis

A

renin release, aldosterone, ADH, ANP, activation of thirst

58
Q

what is the response in kidney homeostasis

A

natriuresis, diuresis, water consumption