731. Concerning the Islets of Langer hans
A. The B cells make up 90% of the islets
B. The D cells secrete pancreatic polypeptide
C. Beef insulin is structurally more like human insulin than pork insulin IS
D. The release of insulin involves depolarisation of the cell membrane, causing opening of calcium channels
E. Hyperkalaemia increases the secretion of insulin
732. In the thyroid gland
A. Passage of iodide from the thyroid cells into the colloid is an active process
B. RT3 is inert
C. Most T4 is metabolised to T3
D. Thyroglobulin is formed in the colloid
E. Thyroxine binding globulin has the highest capacity to bind thyroid hormones in the plasma
733. The effects of thyroid hormones include all of the following EXCEPT
A. Increased activity ofNaIK ATPase
B. Increased nitrogen excretion
C. Increased levels of catecholamines
D. Increased carbohydrate absorption from the gut
E. Increased alpha myosin heavy chains in cardiac muscle fibres
734. Concerning insulin
A. Alpha adrenergic stimulation inhibits insulin secretion
B. Theophylline inhibits insulin secretion
C. Insulin has a half life of about 30 minutes in the circulation
D. Insulin inhibits K uptake into muscle and adipose cells
E. Somatostatin stimulates insulin secretion
735. Actions of glucocorticoids include all of the following EXCEPT
A. Gluconeo genesis in the liver
B. Maintenance of myocardial contractility
C. Inhibition of glucose uptake by muscle and adipose tissue
D. “Permissive” effect on Angiotensin II
E. Decrease in vascular resistance
736. Concerning calcium metabolism
A. The net effect of parathyroid hormone is to decrease serum phosphate
B. Vitamin D decreases renal excretion of both Ca and P04
C. Calcitonin is secreted by parathyroid chief cells
D. Insulin decreases bone formation
E. Thyroid hormones decrease calcium excretion in urine
737. Which of the following is true of the renin angiotensin system
A. Renin causes release of aldosterone
B. Increased Na reabsorption at the macula densa causes increased renin secretion
C. Angiotensinogen is converted to Angiotensin I in the lungs
D. Prostaglandins increase the secretion of renin
E. Oestrogens decrease production of angiotensinogen
738. Concerning vasopressin
A. Diabetes insipidus is characterised by polydipsia and polyuria
B. Secretion of vasopressin is stimulated by alcohol
C. Surgical stress inhibits secretion of vasopressin
D. Preprooxyphysia is the precursor of vasopressin
E. Vasopressin is absent in hippopotamuses
739. Which of the following is true concerning temperature regulation
A. Vaporisation of sweat accounts for 70% of heat loss
B. Increased TSH is an important response to cold
C. Anterior hypothalamic stimulation causes shivering
D. Bacterial toxin act on the OVLT to produce fever
E. None of the above
740. With respect to thirst, which of the following is true
A. Angiotensin II acts on the supraoptic nucleus to stimulate thirst
B. Drinking and vasopressin secretion are regulated in much the same way
C. Dry mucous membranes stimulate thirst via the hypothalamus
D. Secretion of oxytocin causes thirst due to its similarity to vasopressin
E. ACE inhibitors decrease thirst in response to hypovolaemia by decreasing Angiotensin II