April 2009 Mock Physio

1. Hyponatremia a. may increase intracellular fluid volume b. may be seen in SIADH c. may increase the secretion of ANP d. may increase the plasma osmolality e. of acute onset may be associated with cerebral oedema 2. The following statements are true: a. normal plasma osmolarity is in the range of 300-315mosm/L b. one mole of sodium chloride in a litre of water has a concentration of 2osm/L c. osmolarity refers to osmoles per litre of fluid d. depends on the size of the particles in solution e. total osmotic pressure of plasma is higher than atmospheric pressure 3. Siggard-Anderson curve normogram a. has pCO2 on the vertical scale b. has pH on the horizontal scale c. determines standard bicarbonate content after plotting measures pCO2 and pH of a blood gas sample d. plots base excess on a secondary axis e. allows estimation of the buffer base content 4. Concerning buffers a. buffers are least efficient when half dissociated b. carbonic anhydrase is an important component of the physiological buffering system c. phosphate is an important extracellular buffer d. oxygenated haemoglobin is a more powerful physiological buffer than deoxygenated haemoglobin e. the imidazole ring structure of haemoglobin is the site of H+ exchange for physiological buffering 5. The rate of diffusion of a gas a. is a result of the random movement of the gas molecules b. is proportional to the tension gradient c. depends upon the gas temperature d. is inversely proportional to the square root of the density at constant temperature e. CO2 diffuses more rapidly than oxygen

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6. Physiological dead space: a. includes anatomical dead space b. is unchanged over a two fold range of tidal volume c. accounts for the difference in composition between ‘ideal’ alveolar gas and mixed expired gas d. changes with posture e. is measured by Fowler’s method 7. Which of the following is (are) true with respect to increasing oxygen reserves through preoxygenation with 100% oxygen: a. It is well reflected by the arterial oxygenation saturation. b. It requires longer when using a Bain circuit. c. It is achieved equally as well with 4 vital capacity breaths or 3 minutes of tidal volume breathing. d. Oxygen reserves are reduced in pregnancy. e. Preoxygenation is essential especially in obese patients during rapid sequence induction 8. In calculating the shunt fraction, the following need(s) to be measured or estimated: a. mixed venous oxygen content b. pulmonary end-capillary oxygen content c. arterial oxygen content d. alveolar partial pressure of oxygen e. haemoglobin concentration 9. Surfactant: a. is a mucopolypeptide b. causes a decrease in surface tension c. results in the same surface tension for different sized alveoli d. causes an increase in compliance e. production is reduced after a prolonged reduction in pulmonary blood flow 10. CO2 transport in venous blood a. occurs predominantly by conversion to bicarbonate b. results in an increase in erythrocyte volume c. causes an efflux of hydrogen ions from the erythrocyte d. is inhibited by deoxygenation of haemoglobin e. can occur by carbamino bonding in plasma

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11. Baroreceptors a. in the carotid sinus are innervated by vagus nerve b. are stretch receptors c. reset the threshold for firing in chronic hypertension d. becomes less sensitive by volatile agents e. also respond to changes in blood pH and PaCO2 12. Regarding coronary blood flow a. subendocardium is more vulnerable to ischaemia than epicardium b. adenosine and dipyridamole are coronary vasoconstrictors c. myocardial consumption and coronary blood flow bear a linear relationship d. coronary blood flow may be improved by increasing the heart rate as this improves the cardiac output e. normal myocardial extraction ratio is 70% 13. The following is (are) true about pulmonary capillary wedge pressure (PCWP): a. also known as pulmonary artery occlusion pressure (PAOP) b. position of the pulmonary artery (PA) catheter tip should lie in zone 2 of the lung c. traditionally measured at end of inspiration d. normal value: 6-12mmHg e. reflective of left ventricular end-diastolic pressure in the presence of mitral stenosis 14. Haemodynamic changes seen following Valsalva manoeuvre a. rise in MAP in phase I due to rise in intrathoracic pressure b. in phase II, decreased venous return is responsible for the drop in MAP c. MAP increases in phase III due to rise in heart rate and vasoconstriction d. MAP returns to normal in phase IV e. these changes are seen in autonomic dysfunction 15. With reference to the normal heart a. The most rapidly conducting fibres in the heart the Purkinje’s fibres b. The last part of the ventricle to be activated is the apex c. The duration of action potential in a ventricular muscle fibre is about the same as in a skeletal muscle fibre d. The T wave of the ECG occurs at the beginning of the absolute refractory period of the ventricle e. Left axis deviation leads to abnormally large R wave in standard limb lead I

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16. In a patient with severe hypovolaemia, the: a. physiological dead space increases b. arterio-venous oxygen difference decreases c. alveolar-arterial oxygen difference increases d. minute volume increases e. arterial PCO2 increases 17. About CVP waveform a. a wave is due to atrial systole b. c wave is related to venous return c. c wave is due to ventricular contraction d. giant a wave is due to atrial fibrillation e. v wave is caused by atrial filling during ventricular contraction 18. In a normal healthy man at rest in the supine position a. LVEDV is about 20mls b. The first heart sound coincides with the onset of ventricular systole c. Cardiac output is approximately 75mls /beat d. LVEDP is about 5 mmHg e. The second heart sound coincides with end of T wave of ECG. 19. Regarding juxtaglomerular apparatus and renin angiotensin system a. juxtaglomerular cells are found within the efferent arteriolar wall b. juxtaglomerular cells contains angiotensinogen c. angiotensinogen is converted to angiotensin I in the lungs by angiotensinogen (ACE) d. plays a major role in the regulation of blood pressure control and aldosterone secretion e. renin secretion from the JGA is increased with β-adrenergic sympathetic stimulation 20. In the normal kidney a. one would expect to find more than one million nephrons b. distal tubules do not contains brush border c. proximal tubular cells possess fewer mitochondria than distal tubular cells d. only 20 % of nephrons have a loop of Henle e. the slit membrane of the Bowman’s capsule has pores of 5 mm diameter

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21. Regarding renal physiology: a. When the rate of flow through tubules increases, GFR in the same nephron decreases b. When GFR increases, the solute reabsorption in the tubules also increases c. For each H+ secreted in the renal tubule, one sodium and one HCO3enters the interstitial fluid d. More H+ is secreted in the proximal tubule than in the distal tubule e. Urine becomes more acidic in the presence of low plasma HCO3 22. An increase in aldosterone secretion follows: a. a sodium chloride load b. a rise in blood volume c. an increase in oral potassium absorption d. trauma e. an increase in production of angiotensin II 23. The rate of gastric emptying is: a. delayed by fat in the duodenum b. delayed by secretin c. delayed by fat in the oesophagus d. enhanced by alcohol e. independent of volume and type of food ingested 24. Chemoreceptor trigger zone a. is situated in the area postrema in the 3rd ventricle b. lies outside the blood brain barrier c. is stimulated by dopamine d. is inhibited by 5 HT e. when stimulated sends efferents to the vomiting centre of the medulla 25. Foetal haemoglobin a. is made up of 2 alpha chains and 2 gamma chains b. P50 of ODC (oxygen dissociation curve) for foetal Hb is 18mmHg (2.4kPa) c. binds more avidly to 2,3 DPG than adult haemoglobin d. forms 80% of haemoglobin at time of birth e. may be persistently present even after 2 years of age, especially if associated with haemoglobinopathies

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26. Circulatory changes that occurs at birth: a. increase in pulmonary artery pressure b. Closure of ductus venouses leading to increase in portal venous pressure to about 6-10 mmHg c. decrease left ventricular pressure d. increase systemic vascular resistance e. closure of ductus arteriosus 27. The placenta: a. transports glucose from maternal to foetal blood by facilitated diffusion b. can synthesize glycogen c. actively transports oxygen from maternal to foetal blood d. allows protein molecules to pass from maternal to foetal blood by pinocytosis e. secretes oestradiol 28. Pregnancy at term is associated with a: a. 20% decrease in red cell mass b. rise in cardiac output c. fall in PaCO2 d. fall in haematocrit e. low protein-bound iodine 29. CMRO2 a. CMRO2 is normally about 50ml/min b. is reduced by midazolam c. is greatest in the white matter d. is a measure of global cerebral metabolism e. equals cerebral blood flow X arterio-venous O2 content difference 30. Regarding cerebral blood flow a. brain receives 15% of cardiac output b. cerebral blood flow rises by 2% for each mmHg rise in PaCO2 c. volatile anaesthetics increase cerebral blood flow d. volatile anaesthetics can impair autoregulation of cerebral blood flow e. cerebral blood flow is relatively constant between CPP of 50-150mmHg

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31. CSF and intracranial pressure: a. the partial pressure of carbon dioxide (PaCO2) in the cerebro-spinal fluid (CSF) of a normal person during quiet respiration is approximately 34 mm Hg. b. normal intracranial pressure ranges between 5-15 cm H20 c. total volume of CSF is about 100-150 mls d. is formed by the choroids plexus e. CSF production is about 500 ml/day 32. Which of the following is (are) generally associated with increases in intra-ocular pressure? a. normal blinking. b. the head down position c. miosis d. hypercarbia. e. coughing 33. Concerning sleep a. REM sleep is divided into four stages b. REM sleep makes up 60 % of total sleep time c. REM is associated with slow irregular low amplitude waves on the EEG d. NREM sleep is associated with tachypnoea e. REM sleep is associated with penile erection 34. Normal bile: a. contains phospholipids b. output is 125ml/24hrs c. bile acids are conjugated with taurine and glycine before excretion into bile d. contributes more than pancreatic secretion to the neutralisation of acid from the stomach e. secretion is stimulated by vagal stimulation 35. Hypoglycaemia may result from: a. excessive insulin secretion b. alpha-adrenergic stimulation c. beta-adrenergic stimulation d. glucagon secretion e. hypothermia

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36. Ingested lipid: a. is important in prostaglandin synthesis b. increases in the faeces with a decrease in bile secretion c. is absorbed via the intestinal lymphatics d. is mainly in the form of triglycerides e. can be used as a source of ATP production 37. Capillary permeability is increased by a. bradykinin b. adrenaline c. calcium d. vasopressin e. histamine 38. In thermoregulation: a. respiratory heat loss is insignificant under normal conditions b. brown fat is an important source of heat production in neonates c. shivering is due to impulses conducted via autonomic efferents d. peripheral vasoconstriction increases heat production e. sweating is mediated by sympathetic cholinergic neurons 39. Basal metabolic rate is increased by a. circulating catecholamine b. hypothermia c. pregnancy d. hypothyroidism e. in children 40. Antidiuretic hormone: a. is a polypeptide b. production is sensitive to changes of osmolarity of 2-3 mosmol/l c. alters the permeability to water of the proximal convoluted tubules d. is controlled partly by activity in low pressure stretch receptors e. is controlled partly by activity of osmoreceptors in the anterior hypothalamus

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41. The following statement(s) related to hormones are correct a. hormones can be peptides, proteins, amines, or steroids b. peptide hormones usually binds to a membrane receptor c. steroid hormones usually binds to membrane receptor d. there is only one type of receptor for a hormone e. paracrine secretions act on adjacent cells 42. Parathyroid hormone: a. is secreted by the thyroid gland in patients who have had parathyroidectomy done b. increases calcium absorption from the intestine c. increases the synthesis of 24,25-dihydroxycholecalciferol d. decreases plasma phosphate e. is increased in osteoporosis 43. The following chemical(s) is/are secreted by the anterior adenohypophysis a. oxytocin b. growth hormone c. thyrotrophic releasing hormone d. adrenocorticotrophic hormone (ACTH) e. vasopressin 44. In a consideration of human blood types: a. types A and B are Mendelian dominants b. the ABO group are classified by antigens in the membrane of red cells c. the ABO antigen system is exclusive to blood cells d. the most important reaction is of recipient plasma with donor cell e. Rh-positive means the individual will form anti-D agglutinin to D-positive cells 45. Red blood cell production: a. increases during acclimatization to altitude b. can occur in the spleen c. is dependent on normal gastric secretory activity d. is stimulated by hypercarbia e. is dependent on erythropoietin

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46. Concerning immunoglobulins a. Ig M exists as a pentamer b. Ig A is secretory c. Ig M appears in breast milk d. Ig M crosses placenta e. Ig E relates histamine and heparin from mast cells 47. During the process of haemostasis a. the extrinsic cascade is initiated by contact between factor XII and collagen fibres b. vit K is required for the formation of prothrombin c. local vasoconstriction occurs in response to serotonin released by platelets d. antithrombin III induced release of oxalate from the endothelium prevents extension of the clot e. enteral administration of antibiotics may affect clotting 48. During skeletal muscle contraction: a. the myofilaments do not change in length b. The A and the I bands do not change in length c. calcium is released from the T-tubules d. cross bridges are formed between myosin and actin e. maximal tension can be generated when the muscle is close to its normal resting length 49. The velocity of conduction of a nerve action potential: a. is inversely related to the cross-sectional area of the axon b. is faster in a myelinated fibre than in an unmyelinated one c. is decreased by cooling the nerve d. can exceed 100 m/s in humans e. is highest in pre-ganglionic autonomic fibres 50. Acetylcholine is a neurotransmitter at a. pre-ganglionic nerve endings of parasympathetic nervous system b. pre-ganglionic nerve endings of sympathetic nervous system c. postganglionic sympathetic fibres supplying the sweat glands d. post-ganglionic sympathetic nerve ending innervating the heart e. all post-ganglionic parasympathetic nerve endings

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51. Stimulation of the parasympathetic nervous system: a. increases the heart rate b. decreases the rate of gastric emptying c. dilates the pupil d. causes vasoconstriction e. causes contraction of the detrusor muscle in the bladder 52. Regarding pain: a. glutamate is the major neurotransmitter in the brain and spinal cord b. opioid μ receptors is the most important receptor implicated in the induction and maintenance of central sensitization during pain states c. according to Melzack and Wall’s gate control theory of pain, stimulation of Aδ fibres causes suppression of Aβ and C fibres activity within the spinal cord d. descending inhibitory pathway originates from the periaqueductal grey (PAG) and nucleus raphe magna (NRM) e. the axons of the second order neurons form the spinothalamic tract without crossing the midline 53. Concerning chronic pain: a. Allodynia is increase pain from a normally painful stimulus b. Hyperalgesia is pain from a stimulus that is not normally painful c. Hyperaesthesia includes allodynia and hyperalgesia d. Dysaesthesia includes allodynia and hyperalgesia e. Allodynia and hyperalgesia mean the same 54. 2,3-diphosphoglycerate concentration in red blood cells a. rises acutely following exercise b. is increased by growth hormone and thyroid hormone c. does not affect the p50 of adult haemoglobin d. is increased by a rise in blood pH e. is reduced in the presence of decreased red cell glycolysis 55. Systemic dynamic of the invasive blood pressure monitoring can be improved by: a. increasing the tubing length b. eliminating unnecessary stopcocks c. removing the air bubbles d. frequent flushing of the system e. using high compliance tubing

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56. For exponential processes: a. the rate of change of a process is proportional to the size of the process at that time b. passive exhalation is an exponential process c. the theoretical total length of time taken by an exponential process is infinite d. after 5 half-lives of exponential decay, the process will have fallen to 1% of its initial value e. the time constant is the change in the process in one second 57. The following about pulse oxymeter is (are) true: a. SpO2 may be both falsely low or high in the presence of methaemoglobinaemia b. inaccuracies may result from venous congestion c. SpO2 is low in the presence of carboxyhaemoglobin d. have been reported to cause burns e. inaccurate when the SaO2 is less than 50% 58. Concerning gas flow through a tube a. for laminar flow, halving the radius decrease the flow 8-fold b. viscosity of the gas is a major determinant in turbulent flow c. Reynold’s number greater than 2000 is more likely to result in turbulent flow d. a gas with high density is likely to increase Reynold’s number e. a gas with high viscosity is likely to increase Reynold’s number 59. Capnography: a. normal end tidal tracing has 4 phases b. dead space ventilation causes higher etCO2 compared to PaCO2 c. N2O may interfere with CO2 measurements d. CO2 absorber failure results in high FiCO2 e. superimposed regular oscillations on the capnograph tracing corresponds to the heart beat 60. On tilting a patient from supine to vertical a. reduced renin secretion occurs b. cerebral vascular resistance is reduced c. cerebral blood flow falls d. cardiac output is reduced e. the R-R interval shortens -------end of paper--------

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Answers to physiology paper April 2009 1. FTTFT 2 FTTFT 3 FTFFT 4 FTFFT 5 TTTFT 6 TFTTF 7 FFTTT 8 TTTTT 9. FTFTT 10 TTFFT 11 FTTTF 12 TFTFT 13 TFFTF 14 TTTTF 15 TFFFT 16 TFTTF 17 TFFFF 18 FTTTT 19 FFFTT 20 TTFFT 21 TTTTT 22 FFTTT 23 TTFFF 24 FTTFT 25 FTFTT 26 FTFTT 27. TFFFT 28 FTTTF 29 TTFTT 30 TFTTT

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31 FTTTF 32 TTFTT 33 FFFFT 34 TFTFT 35 TFTFF 36 TTTTT 37 TFFFT 38 TTFFT 39 TFTFT 40 TTFTT 41 TTFFT 42 FTFTF 43 FTFTF 44 TTFTF 45 TTTFT 46TTFFT 47 FTTFT 48 FFFTT 49 FTTTF 50 TTTFT 51 FFFFT 52 TFFTF 53 FFTTF 54 TTFTT 55 FTTFF 56 TTTFF 57 TTFTT 58 FFTTF 59 TFTTT 60 FTFTT

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