MCQ's: Endocrine + Metabolism Flashcards
Regarding catecholamines:
Select true or false for each of the following statements.
E. Phaeochromocytomas is treated with beta blockers as a first line
False.
This could result in unopposed alpha stimulation by the excess noradrenaline causing profound vasoconstriction.
Regarding catecholamines:
How is adrenaline synthesised?
Noradrenaline is a precursor of adrenaline, so, adrenaline is synthesised by the addition of a methyl group to noradrenaline.
Regarding catecholamines:
What is the the rate limiting step in catecholamine synthesis?
The rate limiting step is the hyroxylation of tyrosine
Regarding catecholamines:
Select true or false for each of the following statements.
C. Isoprenaline is synthesised in the adrenal medulla
False.
Isoprenaline is a synthetic compound of similar structure to adrenaline.
Regarding catecholamines:
Select true or false for each of the following statements.
D. Phaeochromocytomas commonly secrete more adrenaline than noradrenaline
False. They most commonly secrete predominantly noradrenaline, though they can be predominanty adrenaline or dopamine secretors.
How many molecules of lactate produced for every glucose metabolised in anaerobic respiration?
2
BMR is measured using what?
Wet Spirometer
Insulin is antagonised by which hormones?
Adrenaline, Noradrenaline, GH, Cortisol
How does insulin affect serum potassium?
Facilitates potassium uptake by cells, reduces serum potassium
Does glucose metabolism to lactate releases ATP at the same rate as oxidation within the mitochondria?
Lactate metabolism much faster at producing ATP than oxidation, can provide ATP supply for 1.5 mins of maximal exercise.
Is lactate reabsorbed/ excreted in the kidneys?
Reabsorbed
What happens to lactate after it is produced?
Can be used to be produce ATP or reconverted to glucose.
Effect of phosphodiesterase inhibitors on glucagon?
Inhibits its release.
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
Everything except protein anabolism, as they both promote building protein.
How does starvation affect the respiratory quotient?
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.
Does starvation produced a metabolic alkalosis or acidosis?
Acidosis secondary to production of ketone bodies - ketoacidosis.
Regarding ketones, what can limit entry of acetyl Co-A into the citric acid cycle?
Oxaloate enzyme
How does ketoacidosis affect serum sodium levels and why?
Causes hyponatraemia because to excrete ketones in the kidney it must be joined to sodium.
Which hormones are secreted by the anterior pituitary gland?
GH, LH, FSH, Prolactin, TSH, ACTH
How is the anterior pituitary connected to the hypothalamus?
By portal vascular system
What hormones are secreted in the posterior pituitary?
Vasopressin and oxytocin
How does Aldosterone exert its effect?
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
From where is vasopressin synthesised and secreted?
Hypothalamus synthesised and posterior pituitary secretes
Vasopressin is a protein or lipid hormone?
Monopeptide hormone
How is posterior pituitary connected to the hypothalamus?
By specialised neurons - these synthesis oxytocin and vasopressin
Aldosterone acts on which part of the kidney?
DCT
Insulin secretion is stimulated by what factors?
Secretion is stimulated by:
- a rise in plasma glucose,
- parasympathetic release of Ach,
- beta 2 adrenoceptor stimulation (adrenaline)
- and amino acids arginine and leucine.
Insulin secretion is inhibited by which hormones?
Release is inhibited by:
- low glucose concentrations,
- noradrenaline (alpha 1)
- and somatostatin.
