Physio MCQ

21683-Concerning biological oxidations 1: phosphorylcreatine synthesis takes place during anaerobic glycolysis false 2: oxidative deamination takes place in the liver true 3: the liver is the major site of urea formation true 4: free fatty acids are oxidized in muscle and heart true 22399-Blood urea concentration may be influenced by 1: glomerular filtration rate true 2: dietary protein intake true 3: hepatic function true 4: body hydration state true 9943-Pulmonary vascular resistance is 1: increased with a rise in pulmonary arterial pressure false 2: approximately 10% of the systemic vascular resistance true 3: decreased with an increase in lung volume false 4: locally controlled by the oxygen tension in adjacent alveoli true 15513-Basophils contain 1: histamine true 2: thromboxanes false 3: heparin true 4: lymphokine false 20385-S.The respiratory quotient of the stomach during secretion of gastric juice is less than one BECAUSE R. the stomach takes up more COb2 from the arterial blood than it puts into the venous blood you answered A: S is true, R is true and a valid explanation of S 14596-Oxygen uptake by haemoglobin in lung capillaries 1: varies directly with the blood pH true 2: varies inversely with PaCO2 true 3: is characterised in the fetus by a shift of the dissociation curve to the left compared with that after birth true 4: varies inversely with the concentration of 2,3 diphosphoglycerate (2,3-DPG) in the red cell true 12494-The following acid-base data pH 7.21 PaCO2 20 mm Hg HCO3 8 mmol/1 BE -19mmol/1 would be most consistent with you answered C: septicaemic shock The data pattern suggests a partially compensated metabolic acidosis because the hypocapnia is accompanied by a low pH and low bicarbonate together with a large negative base excess. This is not due to atelectasis of the lung, because the low PaCO2 would not be accompanied by the extreme hypoxaemia needed to produce such a severe metabolic acidosis (A false), nor is it due to anxiety as the pH would be raised in the presence of the hypocapnia (D false). It is not pyloric obstruction (with vomiting) where one would expect acid loss resulting in metabolic alkalosis (E false). Both starvation and septic shock would result in metabolic acidosis, but the former would be mild and compensated with a higher pH and plasma bicarbonate (B false). Therefore this severe acid-base disturbance would be most consistent with the anaerobic metabolism of septic shock (C true). 9963-A patient suffering from a feverish illness 1: tends to feel coldest while his central body temperature is rising true 2: shows marked body temperature swings with swings in environmental temperature false 3: has a raised basal metabolic rate true 4: sweats only when his central body temperature is rising false 982-With regard to the parenteral administration of fat: you answered E: Omega-3 polyunsaturated fatty acids may modulate the immune response by inhibiting the induction of free-radical lipid peroxides. Correct answer C: Omega-6 polyunsaturated fatty acid triglycerides should be provided in doses adequate to prevent essential fatty acid deficiency. Between 15% to 30% of the total calories administered per day can be provided as fat. There is no specific requirement for short-chain fatty acids. Medium-chain triglycerides can be used as a source of calories. Omega-6 polyunsaturated fatty acid triglycerides should be provided in doses adequate to prevent essential fatty acid deficiency ie. at least 7.0% of total calories. Omega-3 polyunsaturated fatty acids are sometimes referred to as 'Fish Oils'. Whilst they have no established requirement in critically ill patients, they are under clinical investigation as immune - modulating and anti-inflammatory agents. They may regulate the immune response in at least three ways: (1) by increasing membrane fluidity, (2) inducing free-radical lipid peroxides, and (3) by providing precursors for eicosanoid metabolism. 15458-The glomerular filtration rate varies 1: with efferent arteriolar constriction true 2: agents affecting the mesangial cells true 3: with the permeability of the glomerular capillaries true 4: with changes in extracellular volume true 20655-S. Down regulation occurs when a hormone is present in excess of the number of available receptor sites BECAUSE R. the presence of a receptor-hormone complex gradually induces an increase in the number of active receptors you answered C: S is true and R is false 10149-The ability of the kidneys to conserve urinary chloride depends on the 1: efficiency of Na+ reabsorption in the distal tubules true 2: active Cl- reabsorption in the ascending limb of the loop of Henle true 3: efficiency of Na+ reabsorption in the proximal tubules true 4: varying permeability to chloride of the distal convoluted tubules and collecting ducts false 10079-With regard to the testis 1: normal spermatogenesis takes place under the effect of F.S.H. (Follicle Stimulating Hormone) alone false 2: Sertoli cells secrete inhibin which has a negative feedback effect on the anterior pituitary true 3: testosterone from Leydig cells inhibits the release of F.S.H. from the anterior pituitary false 4: testosterone inhibits luteinising hormone secretion at the level of the hypothalmus true Please note that testosterone has no effect on FSH except in large doses. See Ganong, 19th ed, pages 412-413 This question was referred to the Physiology Sub Committee for review on 1 Feb 2002. The following comment was provided by the Sub Committee: The major control of FSH at the pituitary level is feedback by the hormone inhibin from the Setoli cells of the seminiferous tubules. Large doses of testosterone do indeed inhibit GnRH release at hypothalamic level, thereby reducing the drive on secretion of both LH and FSH. However in terms of the "big picture" on control of gonadotrophin secretion, LH is mainly under negative feedback control by testosterone, thus stabilising testosterone levels, while FSH is mainly under control of inhibin, thereby stabilising spermatogenesis. The answer is thus somewhat of a judgement call. This type of question, where there is merit on both sides, tends to get trickier the longer you look at it. 23244-In the blind loop syndrome 1: the harmful effects are caused by bacterial invasion of the small intestine true 2: steatorrhoea is a clinical feature true 3: bacterial overgrowth may contribute to the development of macrocytic anaemia true 4: jaundice is a clinical feature false 10028-The functional residual capacity of the lung is decreased 1: in the supine position true 2: with chronic obstructive airways disease false 3: with term pregnancy true 4: with positive end-expiratory pressure false 21458-Which of the following statements are correct? 1: the axons of postganglionic parasympathetic neurones are typically short true 2: transmission at parasympathetic ganglia differs pharmacologically from that at sympathetic ganglia false 3: the adrenal medulla is functionally a sympathetic ganglion true 4: the effectors which receive postganglionic sympathetic nerve supply always contain alpha-adrenoceptors false 10422-With regard to arginine: