Saturday, July 17, 2010

ENDOCRINE AND METABOLIC PHYSIOLOGY:

1. Effects of a 24 hour fast:
A. Glycogenolysis or gluconeogenesis CORRECT
B. Protein catabolism – only prolonged fasting
C. Acidosis – only prolonged fasting
D. Ketone production from protein

2. After 24 hours without food or water a healthy young adult will:
A. Deplete glycogen rapidly – No, it should only last about 24 hours (and the question states ‘after’)
B. Develop a metabolic acidosis
C. Demonstrate ketone body formation in the liver - CORRECT
D. Have decreased protein content of body

3. Which hormone causes increased glycogenolysis, increased gluconeogenesis, increased protein anabolism & increased plasma FFA?
A. Cortisol
B. Parathyroid hormone
C. Growth hormone - CORRECT
D. Insulin

4. Which hormone causes increased BSL, increased protein catabolism & increased plasma FFA?
A. Cortisol – Correct
B. Parathyroid hormone
C. Growth hormone
D. Insulin

5.The hypothalamus inhibits the release of:
A. TSH
B. ACTH
C. FSH
D. GH – Correct (somatostatin)
E. Oxytocin

6. Which decreases renin release: mark any 2:
A. PG – No, this stimulates renin secretion
B. Angiotensin II – Correct, negative feedback by A2 on renin release
C. Vasopressin – Correct, this inhibits renin secretion
D. Baroceptor stimulation – No, this would increase renin secretion

7. Secretion of renin is stimulated by:
A. Increased left atrial pressure
B. Increased angiotensin II
C. Decreased right atrial pressure – CORRECT: if this sufficient to activate renal sympathetic nerves
D. erythropoietin

8. Regarding hyperglycaemia: Which of the following is untrue? It causes:
A. Increased H+
B. Increased Na+ (?K+)
C. Increased urine output
D. Increased ECF (or blood volume)
E. Increased glucagon - ANSWER

9. Mechanism of action of ADH:
A. Insertion of water channels (pores) into basolateral membrane – No, apical membrane
B. Increase in GFR
C. Insertion of water channels into luminal (apical) membrane – CORRECT V2 receptors -> Adenalyl cyclase -> cAMP acting on vesicles containing Aquaporin-2 Channels (removed when cAMP levels fall)
C. Increased Na+ uptake in DCT
D. Removal of water pores from apical membrane

10. ADH and the cortical collecting ducts which is correct:
A. Inserts water channels into the apical membrane – Correct
B. Inserts water channels into the basolateral membrane - Incorrect
C. Increases paracellular flow
d. removal of water pores froma apical membrane.

11. How many hours after a meal is Basal Metabolic Rate (BMR) measured?
A. 1 hour
B. 2 hours
C. 6 hours
D. 12 hours – CORRECT
E. 18 hour

12. Which ONE of the following is a water soluble vitamin?
A. Vitamin A
B. Vitamin B – Correct
C. Vitamin D
D. Vitamin E
E. Vitamin K

13. regarding Insulin receptor
A. Receptor site intracellular – No, extracellular (2 alpha subunits), and the 2 beta subunits are intracellular
B. Inactivates tyrosine kinase – Insulin binds to receptor, triggering the tyrosine kinase activity of the beta
subunits
C. Activates membrane glucose transport - CORRECT
D. Acts via activation of transport protein to increase glucose transport into cells

14. How does insulin act?
A. Voltage gated ion channels
B. Tyrosine kinase membrane receptor - Correct
C. Nuclear receptor
D. G protein

15. Heat production at rest is mostly due to:
A. Skeletal muscle activity
B. Na,K ATPase pump CORRECT -accounts for about 30% of basal activity, most is actually for ATP synthesis
C. Dynamic action of food
D. activity of heart

16. Decreased heat production under general anaesthesia is due to:
A. Decreased skeletal muscle tone – Correct
B. Decreased anterior pituitary function
C. Vasodilatation
D. Starvation
E. Decreased Na+/K+ ATPase activity

17. Heat loss in anaesthesia due to
A. Loss Na/K ATPase
B. Loss of skeletal muscle tone
C. Vasodilatation – Correct
D. Respiratory tract

18. Angiotensinogen secretion is increased by:
A. ACTH -CORRECT - glucocorticoids increase angiotensinogen secretion (Ganong, p439)
B. Beta-endorphin
C. Growth hormone
D. Antidiuretic hormone
E. Prolactin

19. The energy value of 1g of carbohydrate is:
A. 3 kcal
B. 4 kcal – CORRECT - 4.1kcal/g liberated from carbohydrate
C. 5 kcal
D. 7 kcal
E. 9 kcal

20. G protein coupled receptors. All true EXCEPT:
A. Seven transmembrane components
B. Hydrophobic links
c. G protein has intrinsic GTPase activity – CORRECT ., the alpha-subunit has GTPase activity
D. The receptor is a heterotrimeric protein – No, the G protein is – the receptor is coupled to it - ANSWER

21. Endothelins:
A. Produced by damaged vascular endothelium
B. Vasoactive
C. Found in brain & intestine
D. all are correct. - ANSWER

22. low respiratory quotient in a septic patient is due to:
A. Increased lactic acid
B. Fat metabolism – Correct, sepsis -> increased fat metabolism -> decreased RQ
C. Increased ventilation
D. Fever

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