2006 Physio

PHYSIOLOGY & CLINICAL MEASUREMENT MULTIPLE CHOICE QUESTION(MCQ)

Sunday 1,October,2006

08:00 – 9:30 hrs

INSTRUCTIONS TO CANDIDATES There are sixty (60) questions in this paper. Each question consists of a stem followed b y 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. Candidates are not allowed to take away the question papers from the Examination Hall. All papers are to be returned.

1. Statements regarding intracranial pressure: a. b. c. d. e.

2.

Regarding EEG patterns: a. b. c. d. e.

3.

Hypocarbia may cause seizure foci and increase in EEG activity Hypocarbia slows EEG activity Extreme hypercarbia will cause burst suppression Hypoxia slows EEG pattern Severe hypotension is needed before significant changes are seen

The substantia gelatinosa: a. b. c. d. e.

4.

Normal ICP is between 10 to 15 mmH2O ICP increase will cause no change in cerebral perfusion pressure Plateau waves are decreases in ICP seen after mannitol diuresis Increased cerebral venous pressure will increase ICP Supine position will not increase ICP.

Control muscle co-ordination Is not influence by TENS Modulates pain transmission Contains kappa receptors Is a site of action of substance P

Sympathetic nerve fibers to the head: a. b. c. d. e.

Arise from the upper 3 thoracic spinal cord segments Synapse in the stellate ganglionid Travel with carotid and vertebral arteries Constrict the pupilsies Does not possess cholinergic fibres

5.

The cerebro-spinal fluid (CSF): a. b. c. d. e.

6.

The knee jerk reflex: a. b. c. d. e.

7.

Is mediated via L1-2 Is mediated via afferent impulses from receptors in the patellar tendon Is mediated via efferent impulses from receptors in the quadriceps muscle Is a monosynaptic reflex Does not disappear under deep general anaesthesia

Regarding blood transfusion: a. b. c. d. e.

8.

Has a pressure that varies with arterial pulse Has a pressure that varies with venous pressure Has a pressure that influences intraocular pressure Is a transudate Protein content rises in spinal analgesia

citrate toxicity is a direct effect of citrate on the vascular smooth muscle with resultant hypotension. citrate toxicity is aggravated by hypotension citrate toxicity is aggravated by hypothermia. it is appropriate to give cryoprecipitate from a type AB donor to a type A recipient. it is appropriate to give FFP from a type B donor to a type AB recipient.

Platelets

a. b. c. d. e.

9.

The function of Von Willebrand’s Factor include: a. b. c. d. e.

10.

optimal activity of factor IX optimal activity of factor VIII prevention of clot lysis optimal platelet function may be improved with desmopressin administration.

Regarding plasma a. b. c. d. e.

11.

impaired platelet aggregation from deficiency of Factor VIII occurs in Sickle Cell disease. Young platelet cells are stored in the spleen for 7 days before being released in blood. Platelet cell transfusion must be given according to ABO blood type compatibility. Platelet cell transfusion carry high risk of bacterial contamination. the platelet antibodies that may be found in patients after multiple platelet transfusions are those antibodies that act against ABO antigens.

concentration of factor VIII in plasma necessary for hemostasis during major surgery is greater than 30% of normal. FFP is not considered a first line treatment for Hemophilia A. Factor VIII concentrates carry more risk of viral infection than cryoprecipitate. Elimination half-life for factor VIII is 36-48 hours. Cryoprecipitate is rich in plasma cholinesterase.

Stored whole blood: a. b. c. d. e.

P50 increases with length of time stored Plasma PH decreases with length of storage Sodium increases with length of time stored Metabolic alkalosis frequently follows massive transfusion. RBC in ADSOL storage bag will have 35 days of survival.

12.

The prothrombin time is increased in: a. b. c. d. e.

13.

GIT hormones mediate he following actions: a. b. c. d. e.

14.

gastrin increases gastric motor activity gastric inhibitory polypeptide inhibits insulin secretion pancreatic polypeptide stimulates pancreatic bicarbonate secretion. Enteroglucagon decreases small bowel transit Secretin maintains mucosal growth.

Regarding the liver a. b. c. d. e.

15.

Warfarin therapy Christmas disease Haemophilia A Liver failure. Von willebrand Disease

45% of the blood flow is from hepatic artery. Oxygen consumption is 35% in normal condition Normal portal pressure is 7-10 mHg When hepatic artery blood flow is decrease, the portal venous blood flow will increase accordingly Hepatic venous compliance is mainly mediated via alphaadrenergic receptors

In the foetal circulation before birth: a.

the PO2 is higher in the ductus venosus than in the ductus arteriosus

b. c. d. e.

16.

Carbonic anhydrase is found at high concentration in: a. b. c. d. e.

17.

total body vitamin C HCI in the stomach An intact colonic mucosa Total body iron Erythropoietin levels in the blood

Ingested lipid: a. b. c. d. e.

19.

plasma red blood cells renal tubular cells gastric parietal cells cardiac muscle cells

Iron absorption is dependent on: a. b. c. d. e.

18.

blood can go from the right atrium to the aorta without passing through the left atrium and ventricle the PO2 in the aortic arch is higher than in the descending aorta blood flowing through the foramen ovale comes principally from the superior vena cava blood passes through the ductus arteriosus because of the high pulmonary vascular resistance.

is important in prostaglandin synthesis increases in the faeces with a decrease in bile secretion is absorbed via the intestinal lymphatics is mainly in the form of triglycerides can be used as a source of ATP production

Transferrin is: a. b.

involved in iron uptake by the gut mucosa involved in iron transport across the gut mucosa

c. d. e.

20.

Bile: a. b. c. d. e.

21

saits contribute to the solubility of cholesterol in the bile contains bilirubin mainly in the unconjugated form contributes more than pancreatic secretion to the neutralization of acid from the stomach becomes more alkaline following concentration in the gall bladder is produced at a rate of approximately 2000 ml/day

Regarding Insulin and or glucagon a b c d e

22

involved in iron transport to muscle involved in iron transport to storage sites normally only 35% saturated with iron

both are produced by the islet cells of the pancreas glucagon is a 70 amino acid polypeptide 80% of insulin released is degraded by the liver The insulin/glucagons ratio is approximately 30 all the time Insulin has a molecular weight of 5734 Da

Anti Diuretic hormone a. has a half life of 20 minutes b. is a decapeptide c. stimulation of V1 receptors mediate vasoconstriction d released by the anterior pituitary gland e. stimulated by hyperosmolality

23.

Aldosterone

a. is a C21 corticosteroid b. has a half life of > 1 hour c. tetrahydroaldosterone is a metabolite d. acts via G-protein

e.

conjugated with glucuronide and excreted by the kidney

24

Thyroid hormones

a. thyroxine is secreted as a majority b. reversed T3 is biologically active c. T3 is 5X more active than T4 d. thyroxine reduces BMR e. T4 has a longer halflife than T3 25

in

Regarding control of ventilation a. peripheral chemoreceptors are more important than central chemoreceptors regulation of PaCO2 b. minute ventilation is increased by 5L/min for 1 mmHg rise in PaCO2 c. low arterial PO2 amplifies ventilatory response to CO2 d. prolonged hypoxia, stimulates ventilation e. increase in ventilation, produced by low PaO2 is greatest when PaO2<60mmHg

26 A rise in arterial hydrogen ion concentration a. b. c. d. e.

27.

stimulate carotid bodies to increase ventilation stimulate aortic bodies to increase ventilation do not pass easily through the blood-brain barrier inhibit central chemoreceptors may be caused by chronic hypoxia

During normal aerobic exercise a b. c. d. e.

PaO2 falls PaO2 does not change pH does not change systemic venous PCO2 falls venous PO2 rises

28.

Regarding O2 transport a. b. c. d. e.

29

c

30

O2 flux a. is approximately 250ml/min b depends on cardiac output dissolved O2 follows Henry’s Law d dissolved O2 contributes the larger form compared with biochemical form e is the same as O2 content

On the O2 dissociation curve a. b c d e

31

Dry room air has a PO2 of 149mmHg Saturated room air has a PO2 of 159mmHg Mitochondrial PO2 may be < 5mmHg Venous admixture contributes to the A-a gradient PaO2 can be calculated from the Alveolar Gas Equation

acidosis shift the ODC to the left P50 for adult Hb is 26mmHg methemoglobin shifts the ODC to the right increasing 2,3 DPG shifts the ODC to the right temperature has no effect on ODC

These variables affect tissue oxygenation a b c d e

Hb concentration O2 saturation Cardiac output O2 consumption P50

32

Regarding P50 a b c d e

33

HbA has a P50 of 18mmHg HbF has a P50 of 26.6mmHg Myoglobin has a higher P50 than HbF The more the value, the lesser it binds to O2 CarboxyHb causes the ODC to shift to the left Regarding carbon monoxide

a b c d e 34

Has a 250X more affinity for Hb than O2 the O2 dissociation curve in the presence of CO is extremely right shifted is colourless is used in the measurement of diffusing capacity COHb causes pulse oximeters to give a falsely high O2 sat reading Carbon dioxide transport

a b c d e

35

is carried in the blood in 2 forms arterial CO2 content is approximately 48ml/dl mixed venous blood contains less CO2 than arterial carbamino compounds contribute 30% to the a-v difference Improved CO2 transport from tissues is due to the Bohr effect

Carbamino compounds are formed by CO2 reaction with a b c d e

terminal groups of proteins amino groups of Arginine amino groups of lysine Hb Plasma proteins

36

CO2 dissociation curve a b c d e

37

In the erythrocyte a b c d e

38

Carbonic anhydase is present in large amount carbonic acid formation is 1000X slower than in plasma CO2 is carried in 3 forms Chloride shift maintains electrical neutrality large amount of CO2 remains in solution Venous admixture

a b c d e

39

mixed venous CO2 content is 52ml/dl pCO2 of mixed venous is approximately 40mmHg CO2 carriage in mixed venous blood is enhanced by Haldane effect DeoxyHb is 3.5X more effective in forming carbamino compounds CO2 dissociation curve is 3X steeper than ODC

produce A-a gradient is a true shunt blood from areas where V/Q is > 1 can be due to lung collapse causes a decrease in PaO2

Anatomical Shunt can be due to a Bronchial veins b Thebesian veins c Congenital heart disease with right to left shunt d pneumonia e ARDS

40.

Adenyl Cyclase

a. b. c. d. e.

41.

The a-wave of the central venous pressure waveform a. b. c. d. e.

42.

is caused by atrial contraction is not seen in atrial fibrillation is caused by atrial filling during ventricular contraction decreases with inspiration is followed by the v-wave

Central venous pressure is greater than pulmonary artery occlusion pressure in a. b. c. d. e.

43.

increases the conversion of ATP to cyclic AMP is closely linked to alpha and beta adrenergic receptors is inhibited by aminophylline release is triggered by cyclic AMP acts at a mitochondrial level

Right ventricular failure Pulmonary embolism Chronic lung disease Pulmonary hypertension Acute pulmonary regurgitation

The capnograph trace: a. plots CO2 on the X-axis versus time on the Y-axis b. elevated phase I is due to rebreathing of CO2 c. a flattened upstroke of phase II represents slow exhalation phase due to obstruction. d. Phase III shows a flat curve with a slight upstroke e. Undulations in phase III may be due to cardiac oscillations.

44.

Cardiac output may be measured by:

a. b. c. d. e.

45.

Automated blood pressure monitors: a. b. c. d. e.

46.

under-reads at high pressure T over-reads at low pressure T need a cuff width 20% greater than diameter of the arm T extrapolate diastolic pressure T tend to be inaccurate with atrial fibrillation. T

Cerebral blood flow is increased by a. b. c. d. e.

47.

Thermodilution T electromagnetic flowmeter T Doppler ultrasound T Limb pletysmography F Ballistocardiography T

Increased level of CO2 in blood 1 MAC of halothane Moderate hypothermia Etomidate Ketamine

Regarding Cardiac Action Potentials a. b. c. d.

Phase 0 is due to the opening of fast sodium channels Ventricular cell resting membrane potential is – 90 mV Ventricular muscle action potential lasts 150 mseconds 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

48.

The QRS on the ECG

a. b. c. d. e.

49.

Characteristic features of the ECG in hypothermia a. b. c. d. e.

50.

Is a determinant of cardiac output Unaffected by preload Related normally to afterload Is determined normally by heart rate Is independent of myocardial contractility

Systemic arterial pressure is increased a. b. c. d. e.

52.

J wave Long PR interval Wide QRS Nodal bradycardia Long QT interval

Stroke Volume a. b. c. d. e.

51.

Caused by ventricular myocardial repolarisation Will normally contain Q wave up to the half the length of R wave Corresponds to the phase of isovolumetric contraction Is shortened in tricyclic poisoning May be used to assess rotation of the heart on its longtitudinal axis

On assumption of erect from the supine position On sudden exposure to cold Always when heart rate increases By carotid sinus hypoxia In response to stimulation by peripheral chemoreceptors

With respect to circulation in a healthy adult

a. The major proportion of blood volume is accommodated in the low pressure venous circulation b. Decrease of up to 15% blood volume is compensated by increase in vasomotor tone c. A 10% decrease in blood volume results in decrease in cardiac output d. Arterial blood pressure is not a good index of blood loss e. CVP decreases in response to a 10% reduction in circulating blood volume

53.

The Frank Starling mechanism a. b. c. d. e.

54.

The following values for water distribution are correct for a 70 kg person a. b. c. d. e.

55

Relates force of contraction to fibre length Does not operate in human heart Operates only in denervated heart Is abolished by changes in contractility Is unaffected by afterload

TBW 49 Litres ICF 28 Litres ECF 21 Litres Plasma 3.5 Litres Interstitial fluid 3.5 Litres

Serum osmolality of 360 mosmol/kg is compatible a. b. c. d. e.

Excess secretion of ADH Normal serum Uraemia Freshwater drowning Uncontrolled Diabetes Mellitus

56.

The following are true regarding fluid balances a. Fluid requirement of 15 kg child is 3.5 ml/kg/hour b. Insensible losses for 70 kg man in normal environment is more than 1200 mls per day c. Obligatory daily urine production for 70 kg man is 800 mls d. TBW for infants is 80% of body weight e. TBW of infant is 80 mls per kilogram body weight

57

In comparison to ICF, the ECF has a. b. c. d. e.

58

In the kidney a. b. c. d. e.

59.

Greater volume Greater K+ ion concentration Lower HCO3 ion concentration Greater CL ion concentration Greater osmolality

Most sodium is absorbed at proximal tubule Glucose is not excreted if serum glucose concentration is normal Tubular cells secrete ammonia Acetazolamide acts on tubular production of HCO3 ions Aldosterone is secreted by juxtaglomerular apparatus

Na-K pump at the cell membrane a. b. c. d. e.

Requires ATP Inhibited by digoxin Maintains low intracellular chloride concentration Is responsible for active transport of Sodium ions into the cell Is responsible for generation of action potentials

60

Renal Blood Flow a. b. c. d. e.

Subject to autoregulation Greater in cortex than medulla Maybe measured by Fick principle Is approximately 10% of cardiac output Is unaffected in haemorrhagic shock

Mock Exam Answers Physiology 2006

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