McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Biology .
Chapters
| 1. |
Regarding ECG changes, which is CORRECT? |
| A. | hypernatraemia is associated with low voltage complexes |
| B. | the first change in hyperkalaemia is prolongation of QRS |
| C. | with hypokalaemia, the resting membrane potential decreases |
| D. | in hyperkalaemia, the heart stops in systole |
| E. | in hypercalcaemia, myocardial contractility is enhanced |
| Answer» E. in hypercalcaemia, myocardial contractility is enhanced | |
| 2. |
Regarding jugular pressure waves: |
| A. | the ‘v’ wave denotes the increased atrial pressure due to the bulging of the tricuspid valve during isovolumetric ventricular contraction |
| B. | in tricuspid insufficiency, there is a giant ‘A’ wave with each ventricular systole |
| C. | atrial premature beats produce an ‘A’ wave |
| D. | the ‘v’ wave occurs during systole |
| E. | a giant ‘C’ wave (‘cannon wave’) may be seen in complete heart block |
| Answer» C. atrial premature beats produce an ‘A’ wave | |
| 3. |
What factor does not alter cardiac output? |
| A. | standing up |
| B. | sleeping |
| C. | eating |
| D. | exercising |
| E. | pregnancy |
| Answer» B. sleeping | |
| 4. |
What is the O2 consumption of a beating heart at rest? |
| A. | 2ml/100g/min |
| B. | 9ml/g/min |
| C. | 2ml/g/min |
| D. | 2L/100g/min |
| E. | 9ml/100g/min |
| Answer» E. 9ml/100g/min | |
| 5. |
Regarding percentages of blood volume in the body: |
| A. | the heart has 5% |
| B. | the pulmonary circulation has the greatest percentage |
| C. | the venous circulation has 35% |
| D. | the aorta has 2% |
| E. | capillaries have 20% |
| Answer» D. the aorta has 2% | |
| 6. |
What is a biological action of endothelin? |
| A. | dilates vascular smooth muscle |
| B. | produces bronchodilation |
| C. | increase GFR and renal blood flow |
| D. | evokes positive inotropic and chronotropic effects on myocardium |
| E. | inhibits gluconeogenesis |
| Answer» D. evokes positive inotropic and chronotropic effects on myocardium | |
| 7. |
What inhibits gene transcription for endothelin-1 secretion: |
| A. | nitric oxide |
| B. | angiotensin II |
| C. | insulin |
| D. | growth factors |
| E. | catecholamines |
| Answer» A. nitric oxide | |
| 8. |
Regarding NO synthase: |
| A. | it synthesises nitrous oxide from arginine |
| B. | there are 2 isoforms |
| C. | it is inactivated by haemoglobin |
| D. | NOS-1 is activated by cytokines |
| E. | NOS-2 is in endothelial cells |
| Answer» C. it is inactivated by haemoglobin | |
| 9. |
What factor dilates the arterioles? |
| A. | decreased local temperature |
| B. | myogenic theory of autoregulation |
| C. | angiotensin II |
| D. | increased discharge of noradrenergic vasomotor nerve |
| E. | histamine |
| Answer» E. histamine | |
| 10. |
Which is NOT a baroreceptor site? |
| A. | right atria at the entrance of SVC and IVC |
| B. | aortic arch |
| C. | left atria at the entrance of the pulmonary veins |
| D. | pulmonary circulation |
| E. | carotid body |
| Answer» E. carotid body | |
| 11. |
Regarding cerebrospinal fluid: |
| A. | the total volume of CSF is 300mL |
| B. | CSF is absorbed through the choroid plexus |
| C. | the average CSF pressure is 220m-CSF |
| D. | CSF has a higher pH than plasma |
| E. | it contains very low levels of cholesterol relative to plasma |
| Answer» E. it contains very low levels of cholesterol relative to plasma | |
| 12. |
Which substance has equal concentrations in CSF and plasma? |
| A. | Ca2+ |
| B. | K+ |
| C. | Na+ |
| D. | PCO2 |
| E. | glucose |
| Answer» C. Na+ | |
| 13. |
Which vessel has the lowest PO2? |
| A. | maternal artery |
| B. | maternal vein |
| C. | uterine vein |
| D. | umbilical vein |
| E. | umbilical artery |
| Answer» E. umbilical artery | |
| 14. |
During exercise: |
| A. | diastolic BP increases more than systolic BP |
| B. | regional blood flow to the brain doubles |
| C. | cardiac output may increase 15-fold |
| D. | after exercise, BP takes longer to return to normal than heart rate |
| E. | O2 consumption of skeletal muscle may increase 100-fold |
| Answer» E. O2 consumption of skeletal muscle may increase 100-fold | |
| 15. |
Atrial systole: |
| A. | causes a decrease in atrial pressure |
| B. | causes the ‘A’ wave of the jugular pulse |
| C. | causes the ‘C’ wave of the jugular pulse |
| D. | causes the ‘V’ wave of the jugular pulse |
| E. | causes the dicrotic notch of the aortic pulse |
| Answer» B. causes the ‘A’ wave of the jugular pulse | |
| 16. |
The depolarisation of cardiac muscle cells is characterised by: |
| A. | a slow depolarisation, a plateau then a rapid repolarisation |
| B. | initial depolarisation due to a slow Na+ influx |
| C. | repolarisation due to K+ efflux through two types of K+ channels |
| D. | a plateau phase due to slowly opening Na+ channels |
| E. | calcium efflux during the plateau phase |
| Answer» D. a plateau phase due to slowly opening Na+ channels | |
| 17. |
Regarding cardiac electrical properties: |
| A. | all cardiac cells have the same resting membrane potential |
| B. | cholinergic fibres act predominantly by blocking tonic sympathetic input |
| C. | discharge rates of pacemaker tissue does not change significantly with temperature |
| D. | the bundle of HIS is not the most rapidly conducting part of the conducting system |
| E. | the last parts of myocardium to depolarise normally do not include the septum |
| Answer» D. the bundle of HIS is not the most rapidly conducting part of the conducting system | |
| 18. |
Abnormalities causing ECG changes in myocardial infarction include: |
| A. | delayed repolarisation early on |
| B. | delayed depolarisation |
| C. | increased resting membrane potential |
| D. | TQ segment elevation |
| E. | current flow away from the infarct |
| Answer» B. delayed depolarisation | |
| 19. |
Features of the venous system include all of the following EXCEPT: |
| A. | total volume is approximately 55% of the total vascular volume |
| B. | compliance approximately 25 times the arterial side |
| C. | total volume of venules is twice the total capillary volume |
| D. | valves in the cerebral circulation |
| E. | substantial venoconstriction in response to noradrenaline |
| Answer» D. valves in the cerebral circulation | |
| 20. |
Arteriolar constriction is caused by: |
| A. | serotonin |
| B. | ANP |
| C. | NO |
| D. | K+ |
| E. | histamine |
| Answer» A. serotonin | |
| 21. |
Regarding the inputs into the vasomotor centre: |
| A. | baroreceptors causes stimulation |
| B. | chemoreceptors cause inhibition |
| C. | baroreceptors provide significant input below 70mmhg mean arterial pressure |
| D. | atrial stretch receptors inhibit the vasomotor centre |
| E. | direct inputs include pO2 |
| Answer» D. atrial stretch receptors inhibit the vasomotor centre | |
| 22. |
CSF: |
| A. | volume is about 600ml |
| B. | normal pressure is 5-10cm CSF |
| C. | has a higher concentration of creatinine than plasma |
| D. | has a higher concentration of urea than plasma |
| E. | is formed solely in the choroid plexus |
| Answer» C. has a higher concentration of creatinine than plasma | |
| 23. |
Regarding the conduction system of the heart: |
| A. | the right bundle branch (of HIS) divides into anterior and posterior fasicles |
| B. | the AV node contains P cells |
| C. | myocardial fibres have a resting membrane potential of -60mV |
| D. | action potential in the SA and AV nodes are largely due to Na+ influx |
| E. | there are two types of K+ channels in pacemaker tissue – transient and long acting |
| Answer» B. the AV node contains P cells | |
| 24. |
During systole: |
| A. | the peak left ventricular pressure is 160mmHg |
| B. | contraction of the atria propels 70% of the ventricular filling |
| C. | the period of isovolumetric ventricular contraction is 0.5sec???? |
| D. | the end systolic ventricular volume is about 50mL |
| E. | coronary blood flow to subendocardial portions of the left ventricle occur only in systole |
| Answer» D. the end systolic ventricular volume is about 50mL | |
| 25. |
Regarding cardiac output: |
| A. | “energy of contraction is proportional to the initial length of the cardiac muscle fibre” is Fick’s Law of the heart |
| B. | cardiac index is the correlation between resting cardiac output and height |
| C. | sleep decreases cardiac output |
| D. | basal O2 consumption by the myocardium is 2ml/g/min |
| E. | standing normally decreases the length of ventricular cardiac muscle fibres |
| Answer» E. standing normally decreases the length of ventricular cardiac muscle fibres | |
| 26. |
Effects of electrolyte changes: |
| A. | PR interval increases in hyperkalaemia |
| B. | in hyperkalaemia, the heart stops in systole |
| C. | hypercalcaemia causes prolongation of the ST segments |
| D. | hypernatraemia is associated with low voltage electrocardiographic complexes |
| E. | magnesium counteracts digitalis toxicity |
| Answer» E. magnesium counteracts digitalis toxicity | |
| 27. |
Which statement is TRUE regarding cardiac muscle? |
| A. | cardiac muscle fibres are multinucleated |
| B. | they are smaller than skeletal muscle fibres |
| C. | Ca2+ release is triggered by membrane repolarisation |
| D. | the elastic ‘Titin” protein component is greater than in skeletal muscle, adding stiffness |
| E. | the amount of Ca2+ in the sarcoplasmic reticulum is decreased by catecholamine stimulation |
| Answer» B. they are smaller than skeletal muscle fibres | |
| 28. |
Which statement regarding cardiac “work” is FALSE? |
| A. | the energy applied to the blood stream is defined as kinetic plus potential |
| B. | potential energy involves consideration of energy stored in elastic arterial walls and gravity |
| C. | there is an exchange between kinetic and potential energy |
| D. | the largest drop in energy occurs at the level of the precupillary sphincters |
| E. | the higher resistance in smaller calibre vessels corresponds to greater energy losses |
| Answer» D. the largest drop in energy occurs at the level of the precupillary sphincters | |
| 29. |
Which statement about blood flow is FALSE? |
| A. | cardiac output = stroke volume x heart rate |
| B. | the volume of blood pumped through the lungs equals the volume entering the heart |
| C. | Poiseville’s Law predicts the effects of pressure and resistance on cardiac output |
| D. | the resistance of the systemic circulation is 5 to 10 times the pulmonary vascular resistance |
| E. | with constant pressure, a vessel with radius ‘2X ‘ has 16 times the flow of vessel with radius ‘X’ |
| Answer» B. the volume of blood pumped through the lungs equals the volume entering the heart | |
| 30. |
Regarding haemodynamic principles, which statement is FALSE? |
| A. | viscosity of blood with haematocrit of 40 is three times that of water |
| B. | ‘arterial’ blood volume is 10-15% total volume |
| C. | ‘elastance’ measures a vessel’s stiffness or recoil |
| D. | aging causes increased elastance and therefore decrease in resting (unstressed) arterial volume |
| E. | an increase in total peripheral resistance leads to increased arterial volume and BP |
| Answer» D. aging causes increased elastance and therefore decrease in resting (unstressed) arterial volume | |
| 31. |
Considering conduction rates in myocardial cells, which statement is TRUE? |
| A. | Perkinje fibres are subepicardial and are the largest fibres, 4-7 times the width of other fibres |
| B. | Perkinje fibres are ‘fast fibres’, and can conduct a wave of depolarisation at a speed of 4m/sec |
| C. | the duration of the action potential and refractory period in fast fibres is shorter than slow fibres |
| D. | initial depolarisation occurs in fast fibres with a rapid influx of Ca2+ ions from the sarcoplasmic reticulum |
| E. | none of the above statements are true |
| Answer» B. Perkinje fibres are ‘fast fibres’, and can conduct a wave of depolarisation at a speed of 4m/sec | |
| 32. |
With respect to splanchnic circulation: |
| A. | the liver is approximately 50% blood by volume |
| B. | zone 3 of the hepatic acinus is well oxygenated |
| C. | abdominal viscera receive at 30% cardiac output |
| D. | liver receives blood from hepatic artery (1000???ml/min) and hepatic ??? vein (500ml/min) |
| E. | muscular layer of intestinal wall has higher flow of mucosal layer |
| Answer» C. abdominal viscera receive at 30% cardiac output | |
| 33. |
Blood pressure: |
| A. | the sounds of Korotkoff when taking blood pressure are caused by laminar flow |
| B. | the diastolic pressure in resting adults correlates to the muffling of Korotkoff sound |
| C. | pressures obtained by palpation of auscultation methods are usually 2-5mmHg higher |
| D. | if cuff is inflated for some time, it can give falsely low BP readings |
| E. | sounds of Korotkoff occur when velocity of flow through constriction exceeds critical velocity |
| Answer» E. sounds of Korotkoff occur when velocity of flow through constriction exceeds critical velocity | |
| 34. |
Coronary circulation: |
| A. | left coronary artery has greater flow in 50% of people |
| B. | thebesian veins connect arterioles to the heart chambers |
| C. | cusps of the aortic valve occlude orifices of coronary arteries during LV ejection |
| D. | coronary flow at rest is 250ml/min |
| E. | at rest, heart extracts 50% O2 / unit of blood delivered |
| Answer» D. coronary flow at rest is 250ml/min | |
| 35. |
Which statement is FALSE regarding CVS? |
| A. | the primary function of the CVS uses convection |
| B. | secondary function involves heat control |
| C. | the heart is two pumps operating in parallel |
| D. | the same volume of blood passes through each semilunar valve over time |
| E. | the Frank Starling mechanism is used in balancing the output of both ventricles |
| Answer» C. the heart is two pumps operating in parallel | |
| 36. |
Regarding the heart, which is TRUE? |
| A. | the right and left ventricles perform the same amount of work, because the same volume of blood is pumped by each |
| B. | the cross sectional shape of both ventricles is approximately cylindrical |
| C. | the right ventricle pumps by a bellows type mechanism |
| D. | the left ventricle pump action is via reducing cross-sectional area, as a function of radius cubed |
| E. | in pulmonary disease the right ventricle hypertrophies and assumes a crescented shape in cross section |
| Answer» C. the right ventricle pumps by a bellows type mechanism | |
| 37. |
Which is FALSE? Stroke Volume varies with changes in: |
| A. | ventricular contractility |
| B. | arterial pressure |
| C. | end diastolic volume of ventricle |
| D. | blood viscosity |
| E. | right ventricle compared to left |
| Answer» E. right ventricle compared to left | |
| 38. |
Regarding pressure in circulation, which is FALSE? |
| A. | kinetic energy = M.V2(mass x velocity2)2 |
| B. | hydrostatic (gravitational) pressure = potential energy |
| C. | the pressure in a foot vein may be 150 cm??? greater than at aortic root (in upright posture) |
| D. | the same pressure differential applies in arterial system, (in upright posture) |
| E. | the greatest pressure drop occurs in the capillaries |
| Answer» E. the greatest pressure drop occurs in the capillaries | |
| 39. |
Regarding volumes in each compartment, which is FALSE? |
| A. | 3% in LV and aorta |
| B. | 15% in arterial system |
| C. | 7% in capillaries |
| D. | 50% in venous system (systemic) |
| E. | 40% in pulmonary circulation |
| Answer» E. 40% in pulmonary circulation | |
| 40. |
Regarding pressures, which is FALSE? |
| A. | lateral (static) pressure is reduced but prolonged by elastic arteries |
| B. | static pressure increases with gravitation (hydrostatic) pressure increases |
| C. | static pressure does not include kinetic energy |
| D. | greater resistance to flow through a segment of circulation leads to greater loss of energy through that segment |
| E. | kinetic energy becomes more significant in a narrowed segment and converts back to potential energy when the tube widens |
| Answer» B. static pressure increases with gravitation (hydrostatic) pressure increases | |
| 41. |
Regarding flow, which is FALSE? |
| A. | flow is proportional to pressure gradient |
| B. | flow is inversely proportional to resistance |
| C. | Poiseville’s Law relates flow to pressure gradient and factors that influence resistance |
| D. | Poiseville’ Law demonstrates that resistance to flow is largely determined by viscosity and length of tube and radius x 4 |
| E. | if radius of a vessel is halved, the flow may be reduced to 1/16th of previous flow |
| Answer» D. Poiseville’ Law demonstrates that resistance to flow is largely determined by viscosity and length of tube and radius x 4 | |
| 42. |
Which statement about factors affecting blood pressure is FALSE? Factors that increase blood pressure are: |
| A. | increased heart rate |
| B. | increased blood volume |
| C. | pressure rises in increased cardiac output until the amount entering the arterial system equals the amount leaving |
| D. | increased total peripheral resistance |
| E. | increased end systolic volume |
| Answer» E. increased end systolic volume | |
| 43. |
Regarding blood pressure, which is TRUE? |
| A. | M.A.P. = pulse pressure / 2 + diastolic pressure |
| B. | elastance increases progressively with age |
| C. | increase in arterial blood pressure causes a subsequent increase in stroke volume |
| D. | increased sympathetic stimulation may sometimes lead to decreased cardiac output |
| E. | pulse pressure increases with age because of decreased arterial elastance |
| Answer» B. elastance increases progressively with age | |
| 44. |
Regarding red blood cells, all are true EXCEPT: |
| A. | erythropoiesis is stimulated by anaemia and hypoxia |
| B. | after splenectomy, malaria has a higher mortality |
| C. | normal adult haemoglobin is designated α2 β2 |
| D. | about 5% of adult haemoglobin is haemoglobin A2 (α2 δ2) |
| E. | G6PD deficiency increases red cell susceptibility to lysis by drugs and infection |
| Answer» D. about 5% of adult haemoglobin is haemoglobin A2 (α2 δ2) | |
| 45. |
Regarding the function of the heart: |
| A. | at increased heart rates, diastole is shortened more than systole |
| B. | the pericardial sac normally contains about 50ml of fluid |
| C. | during the cardiac cycle, left ventricular ejection begins before right ventricular ejection |
| D. | during expiration, the aortic valve closes before the pulmonary valve |
| E. | the end—diastolic ventricular volume is about 170ml |
| Answer» A. at increased heart rates, diastole is shortened more than systole | |
| 46. |
Regarding flow in vessels: |
| A. | velocity is greatest closest to blood vessel walls |
| B. | turbulence is almost always present at a Reynold’s number greater than 2,000 |
| C. | probability of turbulence in a vessel is directly related to twice the radius |
| D. | flow in vessels is directly related to the fourth power of the ????? |
| E. | turbulence is related to increasing radius |
| Answer» C. probability of turbulence in a vessel is directly related to twice the radius | |
| 47. |
Which of the following does not increase the length of ventricular cardiac muscle fibres? |
| A. | increased total blood volume |
| B. | increased venous tone |
| C. | increased pumping action of skeletal muscle |
| D. | increased negative intrathoracic pressure |
| E. | increased intrapericardial pressure |
| Answer» E. increased intrapericardial pressure | |
| 48. |
Which of the following does not cause a systolic murmur? |
| A. | aortic stenosis |
| B. | anaemia |
| C. | mitral insufficiency |
| D. | tricuspid stenosis |
| E. | normal flow in children |
| Answer» D. tricuspid stenosis | |
| 49. |
Timing of events in the cardiac cycle: |
| A. | right atrial systole begins after left atrial systole |
| B. | the pulmonary closes after the aortic in inspiration |
| C. | right ventricular ejection starts after left ventricular ejection |
| D. | right ventricular systole starts after left ventricular systole |
| E. | right and left atrial systole are synchronous |
| Answer» B. the pulmonary closes after the aortic in inspiration | |
| 50. |
Starling’s Law of the heart: |
| A. | is an example of hetermeric regulation |
| B. | is an example of homomeric regulation |
| C. | is explained by troponin / tropomyosin overlap |
| D. | relates stroke volume to cardiac output |
| E. | bears little relation to in vivo regulation of the heart |
| Answer» A. is an example of hetermeric regulation | |
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