Feb 09 Physio Test

Sessional assessment Masters in anaesthesiology (part 1)

PHYSIOLOGY & CLINICAL MEASUREMENT Part A. SHORT ANSWER QUESTIONS (SAQ) Part B. MULTIPLE CHOICE QUESTION (MCQ)

Wednesday,11 February 2009

0730 – 08:30 hrs

INSTRUCTIONS TO CANDIDATES There are two (2) short answer questions in part A of the paper. Each question carries 10 marks. There are thirty (30) questions in this paper. Each question consists of a stem followed by five possible responses, identified as A, B, C, D, E, which are either true or false. One mark is given for a correct answer and one minus mark for a wrong answer, but a minimum mark for each question is zero. There is no restriction on the number of true or false items in a question. It is possible for all the items in a question to be true, or for all to be false. Mark the answer with a 2B pencil by shading the spaces provided in the answer sheet. You are advised to attempt all the questions. Candidates are not allowed to take away the question papers from the Examination Hall. All papers are to be returned.

Part A Short answer questions:

Question 1. A) Briefly describe the structure of skeletal muscle cell. (3) B) Describe the processes of excitation and contraction within smooth muscle cells. (7)

Question 2. Briefly outline the differences between the pulmonary circulation and the systemic circulation. (10)

Part B

Multiple choice questions 1. The following are examples of buffer systems in the body a. haemoglobin b. glycine c. protein d. phosphate e. bicarbonate 2. The following equation(s) is/are true: a. O2 content = ( [ 0.003mls O2/dl blood per mmHg ] x P O2) + (SO2 x Hb x 1.31ml/dl blood) b. flow = resistance/ pressure gradient c. Bohr equation: VD/VT= PACO2-PECO2/ PACO2 d. total compliance ( lung and chest wall ) = lung compliance + chest wall compliance e. Qs/Qt = CcO2-CaO2/ CcO2-CvO2 3. All the following statements related to respiration and its control is correct a. involuntary breathing is controlled by the brain stem b. the control level of PaCO2 is set around 40 mmHg c .the central chemoreceptors are the principal site of CO2 determined regulation of respiration d. afferent impulses from the thoracic mechanoreceptors run to the brain via vagus nerve e. Pa O2 is more important than Pa CO2 in the control of respiration 4. Pressure volume loop can be used to measure: a. compliance b. functional residual capacity c. work of breathing d. airway resistance e. closing volume 5. Functional Residual Capacity (FRC): a. is less than 1.5 litres in a male b. decreases when supine c. is increased by using PEEP d. is increased in an obese patient e. In the measurement of the FRC, the figure obtained is higher if one uses the helium dilution method compared to body plethysmography

6. Diffusion capacity for oxygen of the respiratory membrane: a. refers to volume of the a gas that will diffuse through the membrane each second for a partial pressure difference of 1 mmHg b. diffusing capacity for oxygen under resting condition averages about 21 ml/min/mmHg c. about 230 mls of oxygen diffuses through the respiratory membrane each min. d. can be increased to five times the resting diffusing capacity under strenuous exercise e. can be affected by the thickness of the respiratory membrane 7. Ventilation/perfusion ratio of less than 1.0 is associated with a. pneumonia b. hypovolaemic shock c. pulmonary oedema d. pulmonary embolus e. pulmonary contusion 8. Factor(s) that increase(s) the P50 of oxygen dissociation curve: a. hypothermia b. CO poisoning c. Acidosis d. decreased 2,3 DPG level in the circulation e. methaemoglobinaemia 9. Concerning carbon dioxide transport in blood: a. carbonic anhydrase is present in plasma b. 25 % of carbon dioxide is dissolved c. 50 % is carried as bicarbonate d. transport of carbon dioxide is facilitated by deoxygenated haemoglobin e. some of the carbon dioxide reacts with haemoglobin to form carbamino compounds 10. The following ion channels can be found in the heart: a. voltage gated Ca channel b. delayed rectifying K channel c. inwardly rectifying K channel d. transient inward K channel e. voltage gated Na- channel

11. The QRS on the ECG a. Caused by ventricular myocardial repolarisation b. Will normally contain Q wave up to the half the length of R wave c. Corresponds to the phase of isovolumetric contraction d. Is shortened in tricyclic poisoning e. May be used to assess rotation of the heart on its longitudinal axis 12. Regarding Cardiac Action Potentials a. Phase 0 is due to the opening of fast sodium channels b. Ventricular cell resting membrane potential is – 90 mV c. Ventricular muscle action potential lasts 150 mseconds d. During plateau phase, calcium ion flows through T type calcium channel e. The slow calcium channel is activated at membrane potential of –30 to -40mV

13. The pulse pressure a. increases with an increases in stroke volume b. increases with an increase in left ventricular end-diastolic volume c. is not directly affected by the arterial partial pressure of oxygen d. would remain unchanged with a rise in systemic vascular resistance e. would remain unchanged with a rise in blood viscosity 14. The Valsalva manoeuvre a. is associated with an initial fall in arterial pressure at the onset of straining b. is associated with bradycardia during the manoeuvre c. causes stimulation of the baroreceptors during the manoeuvre d. results in increased intracranial pressure e. heart rate changes may be absent in diabetes mellitus 15. The following statements(s) related to the endothelium and arterial tone is/are correct: a. thromboxane causes vasoconstriction b. nitric oxide causes vasodilatation c. nitric oxide causes proliferation of smooth muscles d. acetylcholine acts directly on the arteriolar smooth muscles to cause relaxation e. the artery wall consists, going outwards, of endothelium, intima, media and adventitia

16. Regarding the ventricular action potential a. The rapid phase of depolarization is due to sodium influx b. the plateau phase is due to sustained increase in membrane sodium permeability c. repolarisation is associated with an increase in membrane permeability to potassium d. The absolute refractory period last for approximately 1 millisecond e. the refractory period is almost as long as the muscle twitch which it elicits 17. Normal distribution of blood volume: a. 7-8% to the heart b. 9-10 % to the pulmonary circulation c. 15% to the arterial systemic circulation: d. 20 % to the capillary systemic circulation e. 50 % to the venous systemic circulation 18. Glomerular filtration rate (GFR) decreased with a. increase in renal blood flow b. increased capillary pressure c. hypoalbuminaemia d. moderate afferent arteriole constriction e. mesangial cells contractions 19. Renin activity is increased by: a. an increase in circulating adrenaline b. hypotension c. increased sodium ingestion d. an increase in aldosterone output e. hypovolaemia 20. Action of angiotensin II includes: a. sodium reabsorption in proximal renal tubules b. vasoconstriction of blood vessels c. increases the secretion of aldosterone d. potentiates action of nor epinephrine e. stimulates thirst centre 21. The following statement(s) is/ are true regarding the kidneys a. there are approximately 1.3 billion nephrons in each kidney b. they produce aldosterone c. in a resting state, the kidneys receive 12% of the cardiac output d. The blood flow in renal cortex is greater than that in the medulla e. Autoregulation of renal blood flow occurs

22. A person aged 48, weight 70 kg, has the following values measures in their plasma and urine. An infusion of PAH and Inulin has been given to achieve constant blood levels, 100 mls of urine was collected over 2 hours. The patient’s haematocrit is 40%. Plasma comcentration Urine concentration Creatinine 0.10 mmol/L 10.8 mmol/L Urea 4 mmol/L 240 mmol/L PAH 0.05 mmol/L 30 mmol/L Inulin 0.05 mmol/L 6 mmol/L Drug A 1 µmol/L 360 µmol/L Drug B 10 µmol/L 120 µmol/L The following statement(s) is/are true: a. clearance was 90 ml/min b. GFR is 80 ml/min c. Drug A is filtered and not secreted d. Filtration fraction is 0.2 e. Drug B could be protein bound

23. Concerning the knee jerk a. it is a monosynaptic reflex b. the stimulus arises from the tendon c. impulses travel via Ia afferent fibres d. the response is contraction of the quadriceps femoris muscle e. The Golgi tendon organ is an important component 24. Smooth muscle versus skeletal muscle a. smooth muscles have slower onset of contraction b. the maximum force of contraction is often greater in the smooth muscle than that of skeletal muscle c. smooth muscle can have prolonged contraction d. more energy is required to sustain the same tension of contraction in smooth muscle than in the skeletal muscle e. the rapidity of cycling of the myosin cross-bridges in smooth muscle is much slower in the smooth muscle

25. The following statement(s) related to skeletal muscle and its contraction is/are true a. the basic contractile unit is the sarcomere b. at each end of the sarcomere is a Z disc c. thin filaments are attached to the Z disc d. myofibrils contain myosin in the thin filament e. hydrolysis of ATP reduces affinity of myosin for actin

26. Foetal haemoglobin: a. forms approximately 80% of haemoglobin at birth b. is made up of 2 alpha and 2 delta chains c. forms approximately 20% of haemoglobin at the age of 6 months d. has a low affinity for oxygen than adult haemoglobin (HbA) e. is present in β-Thalassaemia major 27. 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 28. Respiratory physiology in the neonate, compared to the adult, shows a. lower lung compliance b. higher airway resistance c. almost entirely diaphragmatic ventilation d. higher physiological dead space e. higher respiratory rate 29. In pregnancy, the following are normal findings a. elevated urea b. elevated alkaline phosphates c. elevated ESR erythrocyte sedimentation rate d. raised white cell count e. reduced pseudocholinesterase activity 30. Bicarbonate a. when the standard bicarbonate is lower than actual bicarbonate it indicates respiratory acidosis b. in metabolic acidosis standard bicarbonate is high c. an uncompensated metabolic acidosis both actual and standard bicarbonate are high and equal d. the actual and standard bicarbonate values can vary by + 2 mEq/L e. actual and standard bicarbonate values can be derived from Siggard-Andersen normogram --------------------------------------end of paper-----------------------------------------------------

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