Free Cardiovascular Physiology MCQs with Answers

• A. Venules
• B. Capillaries
• C. Arterioles
• D. Precapillary sphinctersExplore Anatomy Models

Explanation: Arterioles provide the greatest resistance because their small radius can be actively changed by smooth muscle.

• A. "T" waveSchedule Health Screenings
• B. "Q" wave
• C. "R" wave
• D. "P" wave

Explanation: The T wave represents ventricular repolarization, when the ventricles recover electrically after depolarization.

• A. Closure of the pulmonary valve
• B. Closure of the aortic valve
• C. Rapid filling of the left ventricle
• D. Contraction of the atriaOrder DNA Kits

Explanation: The dicrotic notch is produced when the aortic valve briefly closes at the start of ventricular diastole.

• A. Pulse Pressure
• B. Peripheral vascular resistance
• C. Volume of the circulation per minute
• D. Total Capacity

Explanation: Systemic and pulmonary circuits are arranged in series, so the same volume of blood passes through each circuit per minute.

• A. More than 12 m/sec
• B. 5 to 8 m/sec
• C. 9 to 12 m/sec
• D. 1 to 4 m/sec

Explanation: Purkinje fibres conduct impulses at about 1.5–4 m/s, the fastest conduction rate in the cardiac conduction system.

• A. Reynolds number < 2000
• B. Increase in diameter of blood vessel
• C. Decrease in density of blood
• D. Decrease in velocity of blood

Explanation: Reynolds number rises with increasing blood velocity, density, and vessel diameter, making turbulent flow more likely.

• A. The loudest sound is the diastolic pressure
• B. Systolic pressure estimation tends to be lower than those make by palpatory method
• C. The first sound heard is the systolic pressure
• D. The sounds that are heard are generated in heart

Explanation: In the auscultatory method, the first Korotkoff sound appears when cuff pressure falls just below systolic pressure.

• A. Preload
• B. Myocardial contractility
• C. Heart rate
• D. After load

Explanation: Increased preload, heart rate within physiological limits, and contractility generally increase cardiac output.

• A. is capable of generating impulses
• B. Has rich sympathetic innervation
• C. Has poor cholinergic innervation
• D. Generates impulses at the highest rate

Explanation: The SA node normally sets the rhythm because its pacemaker cells have the highest rate of spontaneous depolarisation.

• A. Increases heart rate
• B. Decreases myocardial irritability
• C. Increases force of contraction
• D. Increases oxygen uptake by heart

Explanation: Adrenaline increases heart rate, myocardial contractility, and cardiac oxygen consumption through predominantly beta-1 effects.

• A. Isotonic relaxation
• B. Isovolumetric relaxation
• C. Isovolumetric contraction
• D. Isotonic contraction

Explanation: The first heart sound is caused by closure of the atrioventricular valves at the beginning of ventricular systole.

• A. Cardiac efficiency
• B. Cardiac index
• C. Mean arterial pressure
• D. Mean stroke volume

Explanation: Cardiac output is the product of heart rate and stroke volume, so dividing cardiac output by heart rate gives the mean stroke volume.

• A. 2.5
• B. 4.25
• C. 5.25
• D. 9.5

Explanation: Cardiac output equals heart rate multiplied by stroke volume and is about 5 L/min at rest; 5.25 L/min is the closest option.

• A. SA node
• B. SA node
• C. AV node
• D. Purkinje fibers

Explanation: The AV node has the slowest conduction velocity, creating a delay that allows the ventricles to fill before ventricular contraction.

• A. Lasts till cardiac contraction
• B. All of the above
• C. A phase of cardiac cycle in which heart cannot be stimulated by any amount of stimulus
• D. Corresponds with duration of action potential
• E. Longer than refractory period in skeletal muscle

Explanation: The cardiac absolute refractory period lasts through most of the action potential and contraction, is longer than in skeletal muscle, and…

• A. Hyperplasia
• B. Hypertrophy
• C. Fatty infiltration
• D. Increased amounts of fibrous connective tissue

Explanation: Increased workload enlarges existing cardiac muscle cells, producing hypertrophy.

• A. Aorta
• B. Artery
• C. Arteriole
• D. Vein

Explanation: Arterioles provide the greatest resistance because their small radius is actively regulated by smooth muscle.

• A. Explains the increase in cardiac output that occurs when venous return is increased
• B. Does not operate during exercise
• C. Does not operate in the failing heart
• D. Explains the increase in cardiac output when the sympathetic nerves supplying the heart stimulated

Explanation: The Frank-Starling law states that greater venous return stretches ventricular fibres and increases the force of contraction, thereby…

• A. Systolic ejection
• B. None of the above
• C. Isovolumetric contraction
• D. Isovolumetric relaxation

Explanation: During systole or diastole, pressure differences keep either the atrioventricular or semilunar valves closed; during isovolumetric phases…

• A. Heart rate
• B. Peripheral resistance
• C. Systolic blood pressure
• D. Venous return

Explanation: Cardiac output is calculated as heart rate multiplied by stroke volume, and venous return strongly influences stroke volume.