831. All of the following affect glomerular filtration except
A. Changes in renal blood flow
B. Urethral obstruction
C. Dehydration
D. Oedema outside the renal capsule
E. Glomerular capillary permeability

832. The thick ascending limb of the loop of Henle
A. Is impermeable to water
B. Has maximal permeability to NaCI
C. Is relatively permeable to water
D. Is impermeable to NaCI
E. Is a site where there is no active transport of sodium

833. In the normal bladder, micturition
A. Is initiated by the pelvic nerves
B. Is coordinated in the lumbar portion of the spinal cord
C. Is initiated at a volume of 600 mLs
D. Is significantly affected by sympathetic nerves
E. Is not facilitated at the level of the brain stem

834. Regarding Starling’s forces operating at the capillaries
A. There is a net outward force of about 0.3 mmHg
B. The filtration coefficient describes the rate of plasma proteins being filtered from the microcirculation
C. Rate of filtration is roughly equal in the different tissues of the body
D. Mean capillary pressure is normally greater than plasma colloid osmotic pressure
E. Lymphatics play no role in maintaining equilibrium of the forces

835. Thyroxine (T4)
A. Secretion is regulated by positive feedback at the hypothalamus
B. Is transported principally by albumin in the blood
C. Causes increased LDL in plasma
D. Is physiologically more active than T3
E. Increases beta receptors in the cardiovascular system

836. Regarding insulin
A. It increases amino acid uptake
B. Its absorption is not affected by the site ofinjection
C. It causes reduced K + uptake by cells
D. It increases protein catabolism
E. It is secreted by the alpha cells in the islets of Langerhan

837. In the autonomic nervous system, beta agonism results in
A. Constriction of the renal vasculature
B. Decreased velocity of conduction in the atrioventricular node
C. Decreased velocity of conduction in the HISlPurkinje system
D. Decreased ventricular contractility
E. Increased insulin and glucagon secretion

838. The reticular activating system
A. Has depressed conduction during anaesthesia
B. Is located in the pons
C. Is a simple collection of parallel nerve fibres
D. Has no input from the cranial nerves
E. Is electrically isolated from the cerebral cortex

839. The content of chylomicrons includes
A. Apoprotein E and Apoprotein A
B. Cholesterol 30%, protein 20%, triglyceride 50%
C. Lethicin 10%, Cholesterol 25%, Triglyceride 65%
D. Protein 2%, Cholesterol 5%, Triglyceride 90%
E. The enzyme protein phospholipase

840. Regarding calcium metabolism
A. The adult human body contains 15% of its body mass as calcium
B. Calcium is passively absorbed from the intestinal brush border
C. Oestrogen inhibits osteoclasts
D. TNF inhibits osteoclasts
E. Corticosteroids stimulate osteoblasts