MCQ's: Endocrine + Metabolism

Question 1

Regarding catecholamines:

Select true or false for each of the following statements.

E. Phaeochromocytomas is treated with beta blockers as a first line

Answer 1

False.

This could result in unopposed alpha stimulation by the excess noradrenaline causing profound vasoconstriction.

Question 2

Regarding catecholamines:

How is adrenaline synthesised?

Answer 2

Noradrenaline is a precursor of adrenaline, so, adrenaline is synthesised by the addition of a methyl group to noradrenaline.

Question 3

Regarding catecholamines:

What is the the rate limiting step in catecholamine synthesis?

Answer 3

The rate limiting step is the hyroxylation of tyrosine

Question 4

Regarding catecholamines:

Select true or false for each of the following statements.

C. Isoprenaline is synthesised in the adrenal medulla

Answer 4

False.

Isoprenaline is a synthetic compound of similar structure to adrenaline.

Question 5

Regarding catecholamines:

Select true or false for each of the following statements.

D. Phaeochromocytomas commonly secrete more adrenaline than noradrenaline

Answer 5

False. They most commonly secrete predominantly noradrenaline, though they can be predominanty adrenaline or dopamine secretors.

Question 6

How many molecules of lactate produced for every glucose metabolised in anaerobic respiration?

Answer 6

2

Question 7

BMR is measured using what?

Answer 7

Wet Spirometer

Question 8

Insulin is antagonised by which hormones?

Answer 8

Adrenaline, Noradrenaline, GH, Cortisol

Question 9

How does insulin affect serum potassium?

Answer 9

Facilitates potassium uptake by cells, reduces serum potassium

Question 10

Does glucose metabolism to lactate releases ATP at the same rate as oxidation within the mitochondria?

Answer 10

Lactate metabolism much faster at producing ATP than oxidation, can provide ATP supply for 1.5 mins of maximal exercise.

Question 11

Is lactate reabsorbed/ excreted in the kidneys?

Answer 11

Reabsorbed

Question 12

What happens to lactate after it is produced?

Answer 12

Can be used to be produce ATP or reconverted to glucose.

Question 13

Effect of phosphodiesterase inhibitors on glucagon?

Answer 13

Inhibits its release.

Question 14

Insulin and growth hormone have directly opposing effects on:

Select true or false for each of the following statements.

A.	Fat catabolism				
B.	Glucose utilisation				
C.	Fat anabolism				
D.	Protein anabolism				
E.	Glycogen production

Answer 14

Everything except protein anabolism, as they both promote building protein.

Question 15

How does starvation affect the respiratory quotient?

Answer 15

Respiratory quotient decreases, the normal range is 0.7 to 1.
At 1 theres more carbohydrate metabolism.
0.7 there is more protein metabolims.

It is the proportion of carbon dioxide produced compared to oxygen consumed.

Question 16

Does starvation produced a metabolic alkalosis or acidosis?

Answer 16

Acidosis secondary to production of ketone bodies - ketoacidosis.

Question 17

Regarding ketones, what can limit entry of acetyl Co-A into the citric acid cycle?

Answer 17

Oxaloate enzyme

Question 18

How does ketoacidosis affect serum sodium levels and why?

Answer 18

Causes hyponatraemia because to excrete ketones in the kidney it must be joined to sodium.

Question 19

Which hormones are secreted by the anterior pituitary gland?

Answer 19

GH, LH, FSH, Prolactin, TSH, ACTH

Question 20

How is the anterior pituitary connected to the hypothalamus?

Answer 20

By portal vascular system

Question 21

What hormones are secreted in the posterior pituitary?

Answer 21

Vasopressin and oxytocin

Question 22

How does Aldosterone exert its effect?

Answer 22

ADH acts primarily at V2 receptors in the collecting duct to upregulate aquaporin channels and resorb water. It has a minor role at the DCT

Question 23

From where is vasopressin synthesised and secreted?

Answer 23

Hypothalamus synthesised and posterior pituitary secretes

Question 24

Vasopressin is a protein or lipid hormone?

Answer 24

Monopeptide hormone

Question 25

How is posterior pituitary connected to the hypothalamus?

Answer 25

By specialised neurons - these synthesis oxytocin and vasopressin

Question 26

Aldosterone acts on which part of the kidney?

Answer 26

DCT

Question 27

Insulin secretion is stimulated by what factors?

Answer 27

Secretion is stimulated by:

• a rise in plasma glucose,
• parasympathetic release of Ach,
• beta 2 adrenoceptor stimulation (adrenaline)
• and amino acids arginine and leucine.

Question 28

Insulin secretion is inhibited by which hormones?

Answer 28

Release is inhibited by:

• low glucose concentrations,
• noradrenaline (alpha 1)
• and somatostatin.