[MCQ] Disorders of the Neurohypophysis- Part 1

I. Start the exam by click the “Start” button

Disorders of the Neurohypophysis- Part 1

Please wait while the activity loads.
If this activity does not load, try refreshing your browser. Also, this page requires javascript. Please visit using a browser with javascript enabled.

If loading fails, click here to try again

Start

Congratulations - you have completed Disorders of the Neurohypophysis- Part 1. You scored %%SCORE%% out of %%TOTAL%%. Your performance has been rated as %%RATING%%

Your answers are highlighted below.

Question 1

Structure of arginine vasopressin (AVP) is ?

A	Five-membered disulfide ring with tripeptide tail
B	Six-membered disulfide ring with tripeptide tail
C	Seven-membered disulfide ring with tripeptide tail
D	Eight-membered disulfide ring with tripeptide tail

Question 1 Explanation:

AVP is a nona-peptide composed of a six-membered disulfide ring and a tripeptide tail.

Question 2

Which of the following is not synthesized via a polypeptide precursor ?

A	AVP
B	Neurophysin
C	Neuroptin
D	Copeptin

Question 2 Explanation:

AVP secretion is synthesized via a polypeptide precursor that includes AVP, neurophysin & copeptin - all encoded by a single gene on chromosome 20..

Question 3

ADH is synthesized in which of the following ?

A	Hypothalamus
B	Anterior pituitary gland
C	Posterior pituitary gland
D	All of the above

Question 4

ADH is released by which of the following ?

A	Hypothalamus
B	Anterior pituitary gland
C	Posterior pituitary gland
D	All of the above

Question 4 Explanation:

Antidiuretic hormone (ADH) is synthesized in supraoptic nuclei of hypothalamus and released by the posterior pituitary gland.

Question 5

Absence of AVP produces which of the following ?

A	Osmotic diuresis
B	Water diuresis
C	Electrolyte diuresis
D	Ionic diuresis

Question 5 Explanation:

Without AVP, cells that line distal tubule & medullary collecting ducts of kidney reabsorb little of the large volume of dilute filtrate that enters from proximal nephron resulting in excretion of very large volumes (0.2 mL/kg per min) of maximally dilute urine (specific gravity ~1.000 & osmolarity 50 mosmol/L). This is called “Water diuresis”.

Question 6

Which of the following is related to the action of AVP ?

A	Aquaporin 1
B	Aquaporin 2
C	Aquaporin 3
D	Aquaporin 4

Question 6 Explanation:

AVP action is mediated via binding to G protein coupled V2 receptors on the serosal surface of the cells that line distal tubule & medullary collecting ducts of kidney, activation of adenyl cyclase & insertion into luminal surface of water channels composed of a protein called aquaporin 2.

Question 7

At high concentrations, AVP action includes ?

A	Smooth muscle contraction of blood vessels & GI tract
B	Glycogenolysis in liver
C	Potentiates ACTH release by corticotropin-releasing factor
D	All of the above

Question 7 Explanation:

All the above effects are mediated by V1a or V1b receptors that are coupled to phospholipase C.

Question 8

AV3V region that controls osmolarity is located in ?

A	Hypothalamus
B	Anterior pituitary gland
C	Posterior pituitary gland
D	Third ventricle

Question 8 Explanation:

AV3V region is located along the anteroventral region of third ventricle and plays a role in controlling osmolarity and ADH secretion.

Question 9

Which of the following stimuli increase ADH secretion ?

A	Increased blood osmolarity
B	Decreased arterial pressure
C	Decreased blood volume
D	All of the above

Question 9 Explanation:

In addition to increased blood osmolarity, decreased arterial pressure and decreased blood volume increase ADH secretion.

Question 10

Osmoreceptors are present in ?

A	Hypothalamus
B	Posterior pituitary
C	Kidney
D	All of the above

Question 10 Explanation:

Osmoreceptors are specialized hypothalamic cells that control AVP secretion through ‘effective’ osmotic pressure of body fluids.

Question 11

Osmoreceptors are extremely sensitive to small changes in the plasma concentration of which of the following ?

A	Sodium
B	Urea
C	Glucose
D	All of the above

Question 11 Explanation:

Osmoreceptors are extremely sensitive to small changes in plasma concentration of sodium but are insensitive to solutes like urea or glucose.

Question 12

The average threshold, or set point, for AVP release corresponds to a plasma osmolarity of about ?

A	280 mosmol/L
B	285 mosmol/L
C	290 mosmol/L
D	295 mosmol/L

Question 12 Explanation:

Average threshold or set point for AVP release corresponds to a plasma osmolarity of ~ 280 mosmol/ L.

Question 13

The average threshold or set point for AVP release corresponds to a plasma sodium of about ?

A	125 meq/L
B	130 meq/L
C	135 meq/L
D	140 meq/L

Question 13 Explanation:

Average threshold or set point for AVP release corresponds to a plasma sodium of about 135 meq/L.

Question 14

In healthy adults, the set point of osmoregulatory system can be lowered by ?

A	Pregnancy
B	Menstrual cycle
C	Acute reductions in blood pressure or volume
D	All of the above

Question 14 Explanation:

Set point of osmoregulatory system can be lowered by pregnancy, menstrual cycle, relatively large acute reductions in blood pressure or volume

Question 15

Which of the following stimulate AVP secretion ?

A	Nausea
B	Acute hypoglycemia
C	Glucocorticoid deficiency
D	All of the above

Question 15 Explanation:

AVP secretion is stimulated by nausea, acute hypoglycemia, glucocorticoid deficiency, smoking and hyperangiotensinemia

Question 16

Emetic center is located in ?

A	Medulla
B	Midbrain
C	Pons
D	Cerebellum

Question 16 Explanation:

Nausea is an extremely potent stimuli & causes immediate, 50- to 100-fold increases in plasma AVP. Emetic stimuli act via emetic center in medulla & can be completely blocked by antiemetics.

Question 17

AVP clearance is due to degradation in ?

A	Liver
B	Kidneys
C	Placenta
D	All of the above

Question 17 Explanation:

AVP has a half life of 10 to 30 minutes. Most AVP clearance is due to degradation in liver and kidneys. During pregnancy, metabolic clearance of AVP is increased three- to four fold due to placental production of an N-terminal peptidase.

Question 18

Thirst osmostat is ‘set’ about how much higher than the AVP osmostat ?

A	2 %
B	3 %
C	4 %
D	5 %

Question 18 Explanation:

Thirst is regulated primarily by an osmostat that is located in anteromedial hypothalamus. Thirst osmostat is ‘set’ ~5% higher than AVP osmostat.

Question 19

Of the fluid filtered by the kidneys, what percentage is reabsorbed isosmotically in proximal tubules ?

A	30 %
B	50 %
C	80 %
D	95 %

Question 19 Explanation:

In a 70-kg healthy adult, kidney filters about 180 L/day of plasma. Of this, ~144 L (80%) is reabsorbed isosmotically in proximal tubule & 8 L (4 - 5%) is reabsorbed without solute in descending limb of Henle’s loop. Remainder is diluted to an osmolarity of ~60 mmol/kg by selective reabsorption of sodium & chloride in the ascending limb.

Question 20

Under AVP influence, solute-free water is reabsorbed osmotically through which of the following cells ?

A	Principal cells
B	Intercalated cells
C	Mesangial cells
D	All of the above

Question 20 Explanation:

Under AVP influence, solute-free water is reabsorbed osmotically through principal cells of collecting ducts.

Question 21

Which of the following aquaporin water channels is located on apical membrane of principal cells of the collecting duct ?

A	Aquaporin 1
B	Aquaporin 2
C	Aquaporin 3
D	Aquaporin 4

Question 21 Explanation:

Aquaporin 2 (AQP 2) water channels are located on the apical membrane. AQP 3 and AQP 4 water channels are located on the basal-lateral surface and water diffuses out of the cell through them.

Question 22

Antidiuretic effect of AVP is mediated via which of the following receptors ?

A	Receptor tyrosine kinase
B	Cytokine receptor–linked kinase
C	G protein–coupled seven-transmembrane (GPCR)
D	Serine Kinase

Question 22 Explanation:

Antidiuretic effect of AVP is mediated via a G protein–coupled V2 receptor that increases intracellular cyclic AMP, thereby inducing translocation of aquaporin 2 (AQP 2) water channels into the apical membrane resulting in an increase in permeability that permits influx of water that diffuses out of the cell through AQP 3 and AQP 4 water channels on the basal-lateral surface.

Once you are finished, click the button below. Any items you have not completed will be marked incorrect. Get Results

There are 22 questions to complete.

←

List

→

Return

Shaded items are complete.

1	2	3	4	5
6	7	8	9	10
11	12	13	14	15
16	17	18	19	20
21	22	End

Return

See all quizzes of Disorders of the Neurohypophysis at here:

1.Structure of arginine vasopressin (AVP) is ?
A. Five-membered disulfide ring with tripeptide tail
B. Six-membered disulfide ring with tripeptide tail
C. Seven-membered disulfide ring with tripeptide tail
D. Eight-membered disulfide ring with tripeptide tail

2. Which of the following is not synthesized via a polypeptide
precursor ?
A. AVP
B. Neurophysin
C. Neuroptin
D. Copeptin

3 ADH is synthesized in which of the following ?
A. Hypothalamus
B. Anterior pituitary gland
C. Posterior pituitary gland
D. All of the above
4 ADH is released by which of the following ?
A. Hypothalamus
B. Anterior pituitary gland
C. Posterior pituitary gland
D. All of the above

5Absence of AVP produces which of the following ?
A. Osmotic diuresis
B. Water diuresis
C. Electrolyte diuresis
D. Ionic diuresis

6 Which of the following is related to the action of AVP ?
A. Aquaporin 1
B. Aquaporin 2
C. Aquaporin 3
D. Aquaporin 4

7 At high concentrations, AVP action includes ?
A. Smooth muscle contraction of blood vessels & GI tract
B. Glycogenolysis in liver
C. Potentiates ACTH release by corticotropin-releasing factor
D. All of the above

8 AV3V region that controls osmolarity is located in ?

A. Hypothalamus
B. Anterior pituitary gland
C. Posterior pituitary gland
D. Third ventricle

9 Which of the following stimuli increase ADH secretion ?
A. Increased blood osmolarity
B. Decreased arterial pressure
C. Decreased blood volume
D. All of the above

10 Osmoreceptors are present in ?
A. Hypothalamus
B. Posterior pituitary
C. Kidney
D. All of the above

11 Osmoreceptors are extremely sensitive to small changes in the
plasma concentration of which of the following ?
A. Sodium
B. Urea
C. Glucose
D. All of the above

12 The average threshold, or set point, for AVP release corresponds
to a plasma osmolarity of about ?
A. 280 mosmol/L
B. 285 mosmol/L
C. 290 mosmol/L
D. 295 mosmol/L
13 The average threshold or set point for AVP release corresponds
to a plasma sodium of about ?
A. 125 meq/L
B. 130 meq/L
C. 135 meq/L
D. 140 meq/L

14 In healthy adults, the set point of osmoregulatory system can be
lowered by ?

A. Pregnancy
B. Menstrual cycle
C. Acute reductions in blood pressure or volume
D. All of the above

15 Which of the following stimulate AVP secretion ?
A. Nausea
B. Acute hypoglycemia
C. Glucocorticoid deficiency
D. All of the above

16 Emetic center is located in ?
A. Medulla
B. Midbrain
C. Pons
D. Cerebellum

17 AVP clearance is due to degradation in ?
A. Liver
B. Kidneys
C. Placenta
D. All of the above

18 Thirst osmostat is ‘set’ about how much higher than the AVP
osmostat ?
A. 2 %
B. 3 %
C. 4 %
D. 5 %

19 Of the fluid filtered by the kidneys, what percentage is reabsorbed
isosmotically in proximal tubules ?
A. 30 %
B. 50 %
C. 80 %
D. 95 %

20 Under AVP influence, solute-free water is reabsorbed osmotically
through which of the following cells ?
A. Principal cells
B. Intercalated cells
C. Mesangial cells
D. All of the above
21 Which of the following aquaporin water channels is located on
apical membrane of principal cells of the collecting duct ?
A. Aquaporin 1
B. Aquaporin 2
C. Aquaporin 3
D. Aquaporin 4

22 Antidiuretic effect of AVP is mediated via which of the following
receptors ?
A. Receptor tyrosine kinase
B. Cytokine receptor–linked kinase
C. G protein–coupled seven-transmembrane (GPCR)
D. Serine Kinase

Disorders of the Neurohypophysis

[MCQ] Disorders of the Neurohypophysis- Part 1

I. Start the exam by click the “Start” button

Disorders of the Neurohypophysis- Part 1

Share this:

Related

[MCQ] Disorders of the Anterior Pituitary and Hypothalamus- Part 7

[MCQ] Disorders of the Neurohypophysis- Part 2

You may also like

Leave a Comment Cancel Reply