Top 80+ Solved Cardiovascular MCQ Questions Answer

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

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

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

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

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

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

a. ventricular contractility

b. arterial pressure

c. end diastolic volume of ventricle

d. blood viscosity

e. right ventricle compared to left

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

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

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

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

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

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

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

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