Physiology Cardiovascular System True/False Question Set

True/False: The second heart sound differs from the first heart sound in that it is occasionally split.

False - Both may be split due to asynchronous valve closure.

True/False: Peripheral differs from central circulatory failure in that it leads to underperfusion of the tissues.

False - Both types of failure lead to underperfusion of the tissues.

True/False: In the brachial artery pulse pressures have a smaller amplitude than aortic pulse pressures.

False - Brachial arterial pulse pressures are greater due to the superimposition of waves reflected

True/False: Arterioles offer more resistance to flow than other vessels since they have richer sympathetic innervation.

False - But it suggests that the resistance they offer may be varied by change in nerve activity.

True/False: Vascular resistance increases by 50 per cent when the vascular radius is halved.

False - By more than 90 per cent; resistance is related to the fourth power of the radius.

True/False: Respiratory failure (low arterial PO2; raised arterial PCO2) leads to decreased cerebral blood flow.

False - CO2 dilates cerebral blood vessels.

True/False: The strength of contraction of left ventricular muscle increases when blood calcium levels fall.

False - Calcium channel blockers decrease cardiac contractility.

True/False: Arterioles offer more resistance to flow than other vessels since they have smaller internal diameters.

False - Capillaries have even smaller internal diameters.

True/False: The pressure drop across the vascular bed in the foot is greater when a subject is in the vertical than when he is in the horizontal position.

False - Changing from the horizontal to the vertical position increases arterial and venous pressures equally.

True/False: Pain due to poor coronary blood flow (angina) may be relieved by providing the patient with a cold environment.

False - Cold vasoconstriction raises arterial pressure and so increases myocardial work.

True/False: In the estimation of cardiac output by an indicator dilution technique, the indicator must mix evenly with the entire blood volume.

False - Complete mixing with the blood is required for estimation of blood volume.

True/False: Hardening of the arterial walls tends to raise arterial compliance.

False - Compliance, the change of arterial volume per unit pressure change, decreases.

True/False: When the heart suddenly stops beating (cardiac asystole) consciousness is lost after 1-2 minutes.

False - Consciousness is lost within about five seconds.

True/False: Factors ensuring that ventricular muscle has an adequate oxygen supply include the good functional anastomoses that exist between adjacent coronary arteries.

False - Coronary arteries are functional 'end arteries' and have few anastomotic connections; sudden occlusion of an artery usually leads to local muscle death.

True/False: Factors ensuring that ventricular muscle has an adequate oxygen supply include the structural arrangements that prevent vascular compression during systole.

False - Coronary vessels are compressed by the contracting myocardium in systole.

True/False: In the heart atrial and ventricular muscle contracts simultaneously in systole.

False - Delay of excitation in the AV bundle makes atrial precede ventricular contraction.

True/False: Ventricular filling begins during isometric ventricular relaxation.

False - During this phase the AV valves are closed and ventricular volume is constant.

True/False: In the heart excitation spreads directly from atrial muscle cells to ventricular muscle cells.

False - Excitation can only pass from atria to ventricles via specialized conducting tissue in the AV bundle.

True/False: Pulmonary embolism (blood clots impacting in lung blood vessels) usually decreases ventilation to perfusion ratios in the affected lung.

False - It rises since pulmonary capillary perfusion falls.

True/False: In the brachial artery pulse pressure falls with decreasing elasticity of the wall.

False - It rises; arterial elasticity normally damps the pulse pressure.

True/False: Systemic hypertension may be caused by the rapid cardiac action of ventricular fibrillation.

False - This ineffective pumping in ventricular fibrillation causes severe hypotension.

True/False: Systemic hypertension may be caused by myocardial thickening (hypertrophy) of the left ventricle.

False - This is a consequence of hypertension, not a cause.

True/False: Arterial pulse contours that have greatly increased pulse pressures are seen in patients with mitral incompetence.

False - This is typical of aortic incompetence.

True/False: In the denervated heart, left ventricular stroke work increases when blood volume falls.

False - This reduces cardiac filling pressure and hence end-diastolic fibre length.

True/False: When the heart suddenly stops beating (cardiac asystole) electric shocks across the thorax should be applied.

False - This treatment (applied with a defibrillator) is given for ventricular fibrillation.

True/False: Isometric (static) exercise differs from isotonic (dynamic) exercise in that it causes a greater increase in pressure in the veins draining the exercising muscle.

True - In dynamic exercise, the muscle pump increases venous return and so decreases venous pressure in dependent veins.

True/False: Veins contain most of the blood volume.

True - Around three-quarters; veins are referred to as 'capacitance' vessels.

True/False: Arterial pulse contours that have sharp peaks indicate rapid left ventricular ejection.

True - As seen in strenuous exercise.

True/False: The strength of contraction of left ventricular muscle increases when end-diastolic ventricular filling pressure rises.

True - As seen in the Frank-Starling left ventricular function curve.

True/False: In the denervated heart, left ventricular stroke work increases when the end-diastolic length of the ventricular fibres increases.

True - As stated in the Frank-Starling Law.

True/False: In atrial fibrillation ventricular rate is lower than atrial rate.

True - Atrial rate is higher than ventricular rate as some impulses are filtered out by the atrioventricular node.

True/False: The velocity of blood flow is greater towards the centre of large blood vessels than at the periphery.

True - Axial flow occurs in large vessels; near the walls, flow velocity is zero.

True/False: Vasovagal fainting or syncope is more likely to occur when standing than when lying down.

True - Because of gravity, pressure in cerebral arteries is lower when standing than when lying down.

True/False: Sympathetic drive to the heart is increased in exercise.

True - Beta-adrenergic blocking drugs reduce exercise tachycardia.

True/False: Intravenous infusions of adrenaline and noradrenaline have similar effects on skin blood flow.

True - Both cause cutaneous vasoconstriction.

True/False: Intravenous infusions of adrenaline and noradrenaline have similar effects on renal blood flow.

True - Both decrease renal blood flow.

True/False: Pain due to poor coronary blood flow (angina) may be relieved by drugs causing peripheral vasodilation.

True - By reducing arterial pressure, vasodilator drugs such as nitrates reduce myocar- dial work.

True/False: In the brachial artery pressure falls when the arm is raised above head level.

True - By the hydrostatic equivalent of the column of blood between it and the heart.from the end of the arterial tree.

True/False: Respiratory failure (low arterial PO2; raised arterial PCO2) leads to warm hands and feet.

True - CO2 is a vasodilator and 'cor pulmonale' is a 'high output' failure.

True/False: The net loss of fluid from capillaries in the legs is increased by leg exercise.

True - Capillary pressure rises during the exercise hyperaemia.

True/False: Narrowing of the lumen of major arteries supplying the leg is associated with delayed healing of cuts in leg skin.

True - Cuts and ulcers are slow to heal because the supply of nutrients is impaired.

True/False: The Purkinje tissue cells in the heart are responsible for the configuration of the qrs complex.

True - Damage to the cells (as in bundle-branch block) changes the pattern of spread of ventricular depolarization, and hence the shape of the QRS complex.

True/False: The absolute refractory period in the ventricles corresponds to the period of ventricular depolarization.

True - Depolarized cells cannot be excited.

True/False: Aortic valve incompetence may cause increase in arterial pulse pressure.

True - Diastolic pressure is abnormally low due to regurgitation of aortic blood into the left ventricle in diastole.

True/False: With increasing distance from the heart, arterial pulse pressure tends to increase slightly.

True - Distal arterial pulse pressure is increased by the superimposition of waves reflected back from the end of the arterial tree.

True/False: Vasovagal fainting or syncope causes loss of consciousness.

True - Due to cerebral ischaemia caused by the abrupt fall in arterial pressure.

True/False: The electrocardiogram shows an irregular saw-tooth appearance in ventricular fibrillation.

True - Due to chaotic electrical activity in the ventricles.

True/False: Severe systemic hypertension may result in impaired vision.

True - Due to damage to retinal blood vessels.

True/False: Ventricular filling is most rapid in the first half of diastole.

True - Due to entry of blood accumulated in the atria during ventricular systole.

True/False: Left ventricular failure tends to cause an increase in left atrial pressure.

True - Due to inadequate emptying of the left ventricle in systole.

True/False: Severe systemic hypertension may result in increased coronary blood flow.

True - Due to increased left ventricular work.

True/False: The strength of contraction of left ventricular muscle increases when strenuous exercise is undertaken.

True - Due to increased sympathetic drive to the ventricles and increased venous return.

True/False: Severe systemic hypertension may result in pulmonary oedema.

True - Due to left ventricular failure.

True/False: When the AV bundle is completely interrupted, as in complete heart block, the ventricular filling shows beat-to-beat variability.

True - Due to loss of the normal sequence of the atrial and ventricular contractions.

True/False: Arterial pulse contours that have slowly rising systolic phases are seen in patients with aortic stenosis.

True - Due to slow expulsion of blood from the ventricle past the stenosed valve.

True/False: Pulmonary embolism (blood clots impacting in lung blood vessels) usually decreases left atrial pressure.

True - Due to the fall in pulmonary blood flow, atrial pressure tends to fall.

True/False: In the electrocardiogram, the r-r interval normally varies during the respiratory cycle.

True - Due to the heart rate changes associated with respiratory sinus arrhythmia.

True/False: Increased sympathetic drive to the heart increases the ejection fraction of the left ventricle.

True - Due to the increased force of contraction.

True/False: In atrial fibrillation the ventricular rate is irregular.

True - Due to the irregularity of the impulses passing through the AV node.

True/False: Severe systemic hypertension may result in increased qrs voltage in certain leads.

True - Due to the left ventricular hypertrophy.

True/False: In the estimation of cardiac output by an indicator dilution technique, the duration of the dilution curve shortens as cardiac output rises.

True - Due to the more rapid passage of indicator past the sampling site.

True/False: In the heart the contracting ventricles shorten from apex to base.

True - Due to the spiral arrangement of some muscle fibres; circular fibres reduce ven- tricular circumference.

True/False: During isometric ventricular contraction the entry and exit valves of the ventricle are closed.

True - Hence no blood leaves the ventricles.

True/False: The net loss of fluid from capillaries in the legs is increased by plasma albumin depletion.

True - Hypoproteinaemia decreases the transmural colloid osmotic pressure gradient.

True/False: Respiratory failure (low arterial PO2; raised arterial PCO2) leads to raised pulmonary artery pressure (pulmonary hypertension).

True - Hypoxia causes generalized pulmonary vasoconstriction.

True/False: The 'A' wave of venous pulsation in the neck is exaggerated periodically in complete heart block.

True - If the atrial and ventricular systoles coincide, the A and C waves merge to give a giant wave.

True/False: Ventricular extrasystoles from the same focus have similar qrs complexes.

True - If the focus is the same, the pathway for ventricular excitation will be the same.

True/False: Ventricular extrasystoles may fail to produce a pulse at the wrist.

True - If they occur early in diastole, poor ventricular filling results in weak contrac- tions and small pulses.

True/False: Sinuatrial node cells are able to generate impulses because their membrane potential is unstable.

True - Impulse generation is due to spontaneous diastolic depolarization of the ce

True/False: Pain due to poor coronary blood flow (angina) may be relieved by correcting anaemia if present.

True - In anaemia, the capacity of the blood to deliver oxygen is decreased but cardiac work increases due to the rise in cardiac output.

True/False: The tendency for blood flow to be turbulent increases when there is a decrease in blood haemoglobin level.

True - In anaemia, the increase in velocity and decrease in viscosity of blood in the hyperdynamic circulation promote turbulence; bruits may be heard over peripheral arteries.

True/False: When the heart suddenly stops beating (cardiac asystole) the physical signs are similar to those of ventricular fibrillation.

True - In both cases there is no useful cardiac output.

True/False: When the AV bundle is completely interrupted, as in complete heart block, the pr interval shows beat-to-beat variability.

True - In complete block, atria and ventricles beat independently at different rates.

True/False: In heart failure the resting cardiac output may be higher than normal.

True - In high output failures; however, the ability to raise cardiac output in exercise is impaired in all types of failure.

True/False: The net loss of fluid from capillaries in the legs is increased by change from the recumbent to the standing position.

True - In the standing position, capillary pressure increases by the hydrostatic equiva- lent of the column of blood below the heart.

True/False: The jugular venous pulse has greater amplitude in patients with tricuspid incompetence.

True - Systolic regurgitation of right ventricular blood can cause giant waves.

True/False: In the denervated heart, left ventricular stroke work increases when right ventricular output increases.

True - This tends to increase left ventricular filling pressure and end-diastolic fibre length.

True/False: Vasovagal fainting or syncope is associated with skeletal muscle vasodilation.

True - This vasodilation reduces peripheral resistance.

True/False: Hyperaemia in skeletal muscle during exercise is normally associated with an increase in cardiac output.

True - This, together with the reflex constriction above, compensate for the fall in mus- cular vascular resistance and thus prevent arterial pressure falling during exer- cise.

True/False: Aortic valve incompetence may cause systolic murmurs in the aortic valve area.

False - Blood regurgitating in diastole causes diastolic turbulence.

True/False: Pulmonary embolism (blood clots impacting in lung blood vessels) usually decreases po2 in pulmonary venous blood.

False - Blood that traverses pulmonary capillaries is adequately oxygenated; cyanosis in patients with pulmonary embolism is usually peripheral cyanosis due to low car- diac output.

True/False: When the heart suddenly stops beating (cardiac asystole) cardiac compression should be applied at a rate of 10-15 per minute.

False - 60-80 compressions/minute are needed to maintain flow to the brain.

True/False: Intravenous infusions of adrenaline and noradrenaline have similar effects on heart rate.

False - Adrenaline increases heart rate; noradrenaline raises mean arterial pressure and causes reflex cardiac slowing.

True/False: Intravenous infusions of adrenaline and noradrenaline have similar effects on skeletal muscle blood flow.

False - Adrenaline increases, and noradrenaline reduces skeletal muscle blood flow.

True/False: Hyperaemia in skeletal muscle during exercise is normally associated with a fall in arterial pressure.

False - Arterial pressure usually rises.

True/False: Local metabolic activity is the chief factor determining the rate of blood flow to the kidney.

False - As in skin, renal blood flow (about one quarter of total cardiac output) greatly exceeds local metabolic needs. The blood is sent to the kidneys for processing.

True/False: Ventricular filling depends mainly on atrial contraction.

False - Atrial contraction accounts for only about 20 per cent of filling at rest.

True/False: Respiratory failure (low arterial PO2; raised arterial PCO2) leads to low voltage p waves in the electrocardiogram.

False - Atrial hypertrophy in cor pulmonale results in prominent P waves.

True/False: The 'A' wave of venous pulsation in the neck is seen just after the carotid artery pulse.

False - Atrial systole precedes the ventricular systole that generates the carotid pulse.

True/False: In the measurement of forearm blood flow by venous occlusion plethysmography the forearm must be kept below heart level during the measurements.

False - Below heart level, the veins fill with blood and are unable to accommodate more during venous occlusion; the forearm must be above heart level.

True/False: With increasing distance from the heart, arterial po2 falls appreciably.

False - Blood cannot release its oxygen until it reaches the exchange vessels.

True/False: In the brachial artery pressure rises markedly when the artery is occluded distally.

False - Blood flows off rapidly via collaterals so that little pressure change occurs.

True/False: Hyperaemia in skeletal muscle during exercise is normally associated with release of sympathetic vasoconstrictor tone in the exercising muscles.

False - Exercise hyperaemia occurs normally in sympathectomized muscles.

True/False: Ventricular extrasystoles are usually associated with a normal qrs complex.

False - Extrasystoles are associated with a prolonged abnormal QRS complex; the impulse pathway from the ectopic focus over the myocardium is abnormal and slow.

True/False: Ventricular filling can occur only when atrial pressure is greater than atmospheric pressure.

False - Filling occurs when atrial pressure exceeds ventricular pressure.

True/False: Aortic valve incompetence may cause decreased myocardial blood flow.

False - Flow increases as ventricular work increases.

True/False: Murmurs (or bruits) may be detected by auscultation over large arteries in healthy adults.

False - Flow is laminar rather than turbulent in normal large arteries.

True/False: In otherwise healthy people, local tissue death follows obstruction of an internal carotid artery.

False - Flow through the circle of Willis normally maintains the viability of the tissue.

True/False: The strength of contraction of left ventricular muscle increases when serum potassium levels rise.

False - High K+ levels decrease cardiac contractility.

True/False: Peripheral differs from central circulatory failure in that hypovolaemia is unusual.

False - Hypovolaemia due to severe haemorrhage is a common cause of peripheral circulatory failure; blood volume may be normal in central circulatory failure.

True/False: Arterioles have a smaller wall:lumen ratio than have arteries.

False - In arterioles the ratio is much greater, at about 1:1.

True/False: The electrocardiogram shows irregular p waves in atrial flutter.

False - In atrial flutter, P waves have a high but regular frequency (about 300/minute).

True/False: Vasovagal fainting or syncope is associated with tachycardia.

False - Increased vagal activity slows the heart and reduces cardiac output.

True/False: In the heart systolic contraction normally begins in the left atrium.

False - It begins at the sinuatrial node in the right atrium.

True/False: The jugular venous pulse is not visible in normal healthy people.

False - It can be seen in healthy people when they lie almost flat.

True/False: In the electrocardiogram, the pr interval corresponds with atrial depolarization.

False - It corresponds to the interval between atrial and ventricular depolarization due to delay of the impulse in the AV bundle.

True/False: The first heart sound corresponds in time with the a wave in central venous pressure.

False - It corresponds with the C wave; the A wave is due to atrial contraction which pre- cedes the first heart sound.

True/False: The first heart sound corresponds in time with the p wave of the electrocardiogram.

False - It corresponds with the QRS complex.

True/False: In the estimation of cardiac output by an indicator dilution technique, the mean indicator concentration under the curve increases as cardiac output rises.

False - It falls as the indicator is diluted in a bigger volume.

True/False: With increasing distance from the heart, arterial mean pressure tends to rise slightly.

False - It falls slightly; blood will only flow down a pressure gradient.

True/False: Left ventricular failure tends to cause an increase in lung compliance.

False - It falls; congestion of pulmonary vessels with blood makes the lungs stiffer.

True/False: Coronary blood flow to the left ventricle increases during early systole.

False - It falls; coronary vessels are compressed by the contracting myocardium.

True/False: The second heart sound differs from the first heart sound in that it is longer lasting than the first sound.

False - It is about 20 per cent shorter.

True/False: The 'A' wave of venous pulsation in the neck is exaggerated in atrial fibrillation.

False - It is absent - there is no effective atrial systole in atrial fibrillation.

True/False: In the measurement of forearm blood flow by venous occlusion plethysmography a collecting cuff is applied to the wrist.

False - It is applied to the upper arm.

True/False: The absolute refractory period in the ventricles is shorter than the corresponding period in atrial muscle.

False - It is longer, as is the duration of its depolarization.

True/False: The velocity of blood flow in capillaries is low because they offer high resistance to flow.

False - It is low because the capillary bed has a large total cross-sectional area.

True/False: Arterioles have a larger total cross-sectional area than do the capillaries.

False - It is smaller, so blood flow velocity is higher in arterioles.

True/False: The first heart sound corresponds in time with closure of the aortic and pulmonary valves.

False - It is synchronous with mitral and tricuspid closure.

True/False: Peripheral differs from central circulatory failure in that cardiac output is usually normal.

False - It is usually reduced in both types of failure.

True/False: In the measurement of forearm blood flow by venous occlusion plethysmography the collecting cuff pressure should be greater than diastolic but less than systolic arterial pressure

False - It must be below diastolic so as not to interfere with arterial inflow.

True/False: During isometric ventricular contraction pressure in the atria falls.

False - It rises as ventricular pressure causes the AV valves to bulge into the atria.

True/False: The velocity of blood flow in the circulation falls as the haematocrit falls.

False - It rises due to the compensatory increase in cardiac output.

True/False: When measuring blood pressure by the auscultatory method the sounds that are heard are generated in the heart.

False - Korotkoff sounds are produced locally by the turbulence of blood being forced past the narrow segment of a partially occluded artery.

True/False: In an adult subject standing quietly at rest, venous pressure in the hand is subatmospheric when the hand is raised above the head.

False - Limb veins collapse above heart level. Negative pressure cannot be transmitted along a collapsed tube so venous pressure is atmospheric in the raised hand.

True/False: The net loss of fluid from capillaries in the legs is increased by lymphatic obstruction.

False - Lymphatic obstruction allows tissue fluid to accumulate; the rise in interstitial pressure reduces the capillary transmural hydrostatic pressure gradient.

True/False: Intravenous infusions of adrenaline and noradrenaline have similar effects on diastolic arterial pressure.

False - Noradrenaline raises diastolic pressure; adrenaline lowers it.

True/False: In otherwise healthy people, local tissue death follows obstruction of a femoral artery.

False - Normally there is adequate collateral circulation. However, if there is advanced arterial disease, sudden obstruction may cause gangrene.

True/False: Sympathetic drive to the heart is increased during a vasovagal attack.

False - Parasympathetic drive slows the heart during a vasovagal attack; sympathetic drive may stimulate the heart during recovery.

True/False: Hardening of the arterial walls tends to raise diastolic arterial pressure.

False - Poor elastic recoil in diastole allows diastolic pressure to fall further.

True/False: During isometric ventricular contraction pressure in the aorta rises.

False - Pressure in the aorta falls as run-off of blood to the tissues continues.

True/False: Pulmonary vascular resistance is regulated reflexly by sympathetic vasoconstrictor nerves.

False - Pulmonary vascular resistance is controlled by local rather than by nervous mechanisms.

True/False: In the estimation of cardiac output using the Fick principle pulmonary venous blood is sampled to measure the oxygen in arterial blood.

False - Pulmonary veins are difficult to catheterize. Blood from any artery may be used since the O2 content of peripheral arterial blood is the same as that in the pulmo- nary vein.

True/False: In the brachial artery pulse waves travel at the same velocity as blood.

False - Pulse waves travel at about ten times the blood velocity.

True/False: The Purkinje tissue cells in the heart lead to contraction of the base before the apex of the heart.

False - Purkinje fibres travel to the apex before proceeding to the base of the heart.

True/False: Sinuatrial node cells are connected to the av node by fine bundles of purkinje tissue.

False - Purkinje tissue is confined to the ventricles; atrial fibres conduct impulses from the SA to the AV node.

True/False: In atrial fibrillation the qrs complexes have an abnormal configuration.

False - QRS complexes are normal since the pattern of ventricular depolarization is normal.

True/False: Factors ensuring that ventricular muscle has an adequate oxygen supply include the sympathetic vasodilator nerve supply to ventricular muscle.

False - Reflex vasodilatation is not important in regulating coronary blood flow.

True/False: In atrial fibrillation respiratory sinus arrhythmia can usually be seen.

False - Sinus arrhythmia indicates normal sinus rhythm.

True/False: Local metabolic activity is the chief factor determining the rate of blood flow to the skin.

False - Skin blood flow is geared mainly to thermoregulation and normally exceeds that needed for skin's modest metabolic requirements.

True/False: In atrial fibrillation the electrocardiogram shows no evidence of atrial activity.

False - Small rapid waves indicate the atrial fibrillation.

True/False: Hardening of the arterial walls tends to raise peripheral resistance.

False - Stiffness of the wall is not a factor determining vascular resistance.

True/False: Left ventricular failure tends to cause an increase in left ventricular ejection fraction.

False - Stroke volume falls; end-diastolic volume rises.

True/False: When measuring blood pressure by the auscultatory method the cuff pressure at which the loudest sounds are heard indicate diastolic pressure.

False - Sudden muffling (Phase 4) or disappearance (Phase 5) of the sounds indicate the diastolic pressure point.

True/False: In the estimation of cardiac output using the Fick principle the po2 of arterial and mixed venous blood are measured.

False - The O2 content of arterial and mixed venous blood are measured.

True/False: Sinuatrial node cells are unable to generate impulses when completely denervated.

False - The SA node has intrinsic rhythmicity and can generate impulses independently.

True/False: Sinuatrial node cells are found in both atria.

False - The SA node is in the right atrium near its junction with the superior vena cava.

True/False: Arterioles offer more resistance to flow than other vessels since they have a smaller total cross-sectional area.

False - The aorta has a much smaller total cross-sectional area.

True/False: When the AV bundle is completely interrupted, as in complete heart block, the atrial beat becomes irregular.

False - The atria continue to beat regularly at normal sinus rate.

True/False: Severe systemic hypertension may result in an increase in the number of myocardial cells in the left ventricle.

False - The cells increase in size (hypertrophy), not in number (hyperplasia).

True/False: Auscultation of the heart can provide evidence of aortic stenosis, if there is a loud pre-systolic murmur in the aortic valve area.

False - The characteristic murmur is a systolic murmur conducted to the neck vessels.

True/False: Left ventricular failure tends to cause an increase in pulmonary oedema when the patient stands up.

False - The decrease in venous return on standing up may relieve pulmonary congestion and hence dyspnoea.

True/False: The pressure drop across the hepatic portal bed is similar to that across the splenic vascular bed.

False - The drop across the splenic vascular bed (about 60 mmHg) is much larger; the hepatic portal bed offers little resistance to flow.

True/False: In the electrocardiogram, the qrs complex follows the onset of ventricular contraction.

False - The electrical event precedes the mechanical event.

True/False: Local metabolic activity is the chief factor determining the rate of blood flow to the lung.

False - The entire cardiac output must pass through the lungs regardless of the local metabolic needs of the pulmonary tissues. It is greatly in excess of the lungs' metabolic needs.

True/False: Coronary blood flow to the left ventricle increases during hypothermia.

False - The fall in metabolic rate and cardiac output in hypothermia reduce cardiac work and lead to a reduction in coronary blood flow.

True/False: During isometric ventricular contraction the rate of rise in pressure is greater in the right than in the left ventricle.

False - The greater force of contraction in the left ventricle gives a greater rate of rise of pressure.

True/False: Isometric (static) exercise differs from isotonic (dynamic) exercise in that it causes a greater increase in muscle blood flow.

False - The increase is less since inflow is obstructed by the sustained compression exerted by the contracting muscle.

True/False: In otherwise healthy people, local tissue death follows obstruction of the hepatic portal vein.

False - The liver has a dual blood supply; the hepatic artery flow can maintain viability.

True/False: Auscultation of the heart can provide evidence of ventricular septal defect, if a loud diastolic murmur is heard.

False - The murmur occurs during ventricular contraction and is therefore systolic.

True/False: Isometric (static) exercise differs from isotonic (dynamic) exercise in that it causes a greater increase in venous return.

False - The muscle pump is more effective in dynamic than in static exercise.

True/False: Pulmonary embolism (blood clots impacting in lung blood vessels) usually decreases right atrial pressure.

False - The obstruction tends to dam back blood in the right heart.

True/False: Cardiac output does not increase in exercise following dener

False - The output does increase due to changes in the filling pressure, level of circulat- ing hormones, etc.

True/False: Pulmonary vascular resistance is decreased when alveolar oxygen pressure falls.

False - The reverse is true; low alveolar PO2 may cause pulmonary hypertension.

True/False: Vasovagal fainting or syncope is more likely to occur in a cold than in a hot environment.

False - The skin vasoconstriction in cold environments raises peripheral resistance.

True/False: The tendency for blood flow to be turbulent increases when there is a decrease in blood density.

False - The tendency is directly proportional to fluid density.

True/False: The tendency for blood flow to be turbulent increases when there is a decrease in blood flow velocity.

False - The tendency is directly proportional to velocity.

True/False: The tendency for blood flow to be turbulent increases when there is a decrease in blood vessel diameter.

False - The tendency is directly proportional to vessel diameter.

True/False: Sympathetic drive to the heart is increased when parasympathetic drive is decreased.

False - The two systems can function independently.

True/False: Veins receive nutrition from vasa vasorum arising from their lumen.

False - Their vasa arise from neighbouring arteries.

True/False: In the heart the left atrial wall is about three times thicker than the right atrial wall.

False - Their wall thickness is similar since the workload of the two atria is similar.

True/False: When the AV bundle is completely interrupted, as in complete heart block, the qrs complex shows beat-to-beat variability.

False - There is usually a single ventricular pacemaker giving an abnormal but regular QRS complex.

True/False: Pulmonary vascular resistance is expressed in units of volume flow per unit time per unit pressure gradient.

False - These are conductance units, the reciprocal of resistance units.

True/False: Pain due to poor coronary blood flow (angina) may be relieved by -adrenoceptor stimulating drugs.

False - These increase heart rate and force and so increase myocardial work

True/False: Ventricular extrasystoles usually occur following a compensatory pause.

False - They are followed by a compensatory pause; the next normal beat may reach the ventricles when they are refractory - a beat is lost.

True/False: When measuring blood pressure by the auscultatory method systolic pressure estimations tend to be lower than those made by the palpatory method.

False - They are usually higher since palpation may fail to detect the first tiny pulses.

True/False: Ventricular extrasystoles indicate serious heart disease.

False - They occur occasionally in many normal hearts.

True/False: Arterial pulse contours that have rapid run-offs and low diastolic pressure suggest high peripheral resistance.

False - They suggest a low peripheral resistance.

True/False: The second heart sound differs from the first heart sound in that it is related to turbulence set up by valve closure.

False - This applies to both heart sounds.

True/False: Systemic hypertension may be caused by hypoxia due to chronic respiratory failure.

False - This constricts blood vessels in the lungs causing pulmonary hypertension but dilates systemic vessels.

True/False: Narrowing of the lumen of major arteries supplying the leg is associated with reduction in the duration of reactive hyperaemias in the calf.

False - Though the hyperaemias have smaller peak values, their durations are longer.

True/False: In the estimation of cardiac output using the Fick principle oxygen uptake is estimated from alveolar po2 measurements.

False - To measure O2 consumption, the subject breathes from a spirometer filled with oxygen with a CO2 absorber in the circuit; an open circuit method may also be used.

True/False: Vascular resistance is greater in the capillary bed than in the arteriolar bed.

False - Total arteriolar resistance exceeds total capillary resistance though the reverse is true for single vessels.

True/False: Hyperaemia in skeletal muscle during exercise is normally associated with capillary dilation due to relaxation of capillary smooth muscle.

False - True capillaries have no smooth muscle; they dilate passively with the rise in capillary pressure due to active arteriolar dilation.

True/False: Pulmonary embolism (blood clots impacting in lung blood vessels) usually decreases pulmonary vascular resistance.

False - Vascular obstruction tends to increase pulmonary vascular resistance and cause pulmonary hypertension.

True/False: Vascular resistance is related to the thickness of the wall of the vessel.

False - Vascular resistance is not related to wall thickness.

True/False: The electrocardiogram shows regular qrs complexes in atrial fibrillation.

False - Ventricular beats are irregular in rate and strength since impulses pass through the AV node in a random fashion.

True/False: Arterioles offer more resistance to flow than other vessels since they have thicker muscular walls.

False - Wall thickness is not a factor determining resistance.

True/False: In heart failure pulmonary oedema occurs when pulmonary capillary pressure doubles.

False - When pulmonary capillary pressure (about 5 mmHg) doubles, it is still less than plasma oncotic pressure (25 mmHg) so fluid does not accumulate in the alveoli.

True/False: In heart failure the arteriovenous oxygen difference during exercise is less than in normal people.

False - With inadequate output, desaturation of blood in the tissues increases.

True/False: With increasing distance from the heart, arterial flow has a greater tendency to be turbulent.

False - With the decreasing vessel diameter and flow velocity, the tendency decreases.

True/False: In an adult subject standing quietly at rest, venous pressure in the superior vena cava is an index of cardiac filling pressure.

True - A central venous pressure line is usually placed here.

True/False: Coronary blood flow to the left ventricle increases during myocardial hypoxia.

True - A fall in PO2 has a potent vasodilator effect on coronary vessels. Adenosine released from hypoxic myocardium is also a potent vasodilator.

True/False: Aortic valve incompetence may cause left ventricular failure.

True - A persistent increase in ventricular workload can lead to ventricular failure.

True/False: Sympathetic drive to the heart is increased in hypotension.

True - A reflex response to decreased stretch of arterial baroreceptors.

True/False: The pressure drop along large veins is similar to that along large arteries.

True - About 10 mmHg or less; both offer little resistance to flow.

True/False: The second heart sound differs from the first heart sound in that it is higher in frequency.

True - About 50 Hz compared with 35 Hz for the first sound.

True/False: Veins undergo smooth muscle hypertrophy when exposed to high pressure through an arteriovenous fistula.

True - Another functional adaptation to resist distension.

True/False: The strength of contraction of left ventricular muscle increases when peripheral resistance is increased as in hypertension.

True - Initially by increased ventricular filling: later by ventricular hypertrophy.

True/False: Cardiac output may not increase when heart rate rises.

True - It depends on what happens to stroke volume.

True/False: In an adult subject standing quietly at rest, venous pressure in the foot is approximately equal to arterial pressure at heart level.

True - It is about 90 mmHg, due to the column of blood (about 1 metre) between the heart and the foot.

True/False: Vascular resistance is related to the vessel's length.

True - It is directly proportional to length.

True/False: Peripheral differs from central circulatory failure in that central venous pressure is low.

True - It is usually raised in central circulatory failure.

True/False: Local metabolic activity is the chief factor determining the rate of blood flow to the skeletal muscle.

True - Local blood flow is largely determined by the vasoactive metabolites such as rising PCO2, H+ concentration and falling PO2. The changes produced by vaso- motornerves are small compared with those produced by metabolites.

True/False: Arterioles play a major role in regulating local blood flow.

True - Local flow varies directly with the fourth power of their radii.

True/False: Cardiac output usually rises when a person lies down.

True - Lying down normally increases the filling pressure of the heart.

True/False: Auscultation of the heart can provide evidence of mitral stenosis, if an early diastolic and pre-systolic murmurs are heard.

True - Mitral flow is greatest in early diastole but rises again during atrial systole.

True/False: Coronary blood flow to the left ventricle increases during arterial hypertension.

True - Myocardial work and metabolism are increased in hypertension.

True/False: The pressure in the hepatic portal vein exceeds that in the inferior vena cava.

True - Otherwise blood would not flow through the portal bed.

True/False: When measuring blood pressure by the auscultatory method wider cuffs are required for larger arms.

True - Otherwise the full cuff pressure may not be transmitted to the artery.

True/False: Pain due to poor coronary blood flow (angina) may be relieved by cutting the sympathetic nerve trunks supplying the heart.

True - Pain sensory fibres from the heart travel with the sympathetic nerves.

True/False: The jugular venous pulse can vary widely in amplitude in patients with complete heart block.

True - Periodic giant waves are seen when atrial and ventricular systoles coincide.

True/False: In the measurement of forearm blood flow by venous occlusion plethysmography a continuous record is made of forearm volume.

True - Plethysmography means volume measurement.

True/False: In the estimation of cardiac output by an indicator dilution technique, the injection and monitoring devices may be placed in the pulmonary artery.

True - Pulmonary artery blood flow equals cardiac output.

True/False: In the estimation of cardiac output using the Fick principle pulmonary blood flow is measured.

True - Pulmonary blood flow=right ventricular output=cardiac output.

True/False: Respiratory failure (low arterial PO2; raised arterial PCO2) leads to right ventricular failure.

True - Pulmonary hypertension can lead to right ventricular failure ('cor pulmonale').

True/False: Narrowing of the lumen of major arteries supplying the leg is associated with reduced arterial pulse amplitude at the ankle.

True - Pulses may be absent with severe narrowing.

True/False: In the electrocardiogram, the rt interval is related to ventricular action potential duration.

True - R indicates the beginning, and T the end, of the ventricular action potential.

True/False: Increased sympathetic drive to the heart increases the rate of conduction in purkinje tissue.

True - Rapid spread of excitation in the ventricles results in more forceful contractions as the ventricular fibres are activated nearly simultaneously.

True/False: Murmurs (or bruits) may be detected by auscultation over the heart in healthy young adults in early diastole.

True - Rapid ventricular filling in early diastole can cause turbulence in healthy young adults and generate a sound (the third heart sound).

True/False: Peripheral differs from central circulatory failure in that ventricular function is usually normal.

True - Reduced ventricular function is the cause of central circulatory failure.

True/False: Vascular resistance is affected by blood viscosity.

True - Resistance is related to Viscosity=Length/Radius4.

True/False: The 'A' wave of venous pulsation in the neck is exaggerated in tricuspid stenosis.

True - Right atrial contraction is more forceful to overcome valvular resistance.

True/False: Systemic hypertension may be caused by excessive secretion of aldosterone.

True - Salt and water retention by the kidneys expands ECF and hence blood volume and cardiac output.

True/False: The absolute refractory period in the ventricles decreases during sympathetic stimulation of the heart.

True - Shortening the refractory period permits higher heart rates.

True/False: Coronary blood flow to the left ventricle increases during stimulation of sympathetic nerves to the heart.

True - Sympathetic stimulation increases the rate and force of contraction; the resulting increase in the rate of production of vasodilator metabolites dilates coronary vessels.

True/False: Hardening of the arterial walls tends to raise systolic arterial pressure.

True - Systolic ejection causes greater pressure rise when arteries are less distensible.

True/False: In heart failure oedema occurs in dependent parts of the body.

True - The back pressure in veins raises capillary hydrostatic pressure and results in oedema in dependent parts where venous pressure is already raised due to grav- ity.

True/False: The electrocardiogram shows regular qrs complexes in complete heart block.

True - The beats generated by ventricular pacemakers have slow but regular frequency.

True/False: During isometric ventricular contraction left coronary blood flow falls.

True - The blood vessels are squeezed by the contracting myocardium.

True/False: In otherwise healthy people, local tissue death follows obstruction of a retinal artery.

True - The collateral circulation is not good enough to prevent this.

True/False: Auscultation of the heart can provide evidence of the direction of turbulent flow causing a murmur.

True - The direction in which the murmur is conducted indicates the direction of flow.

True/False: Arterioles offer more resistance to flow than capillaries.

True - The drop in pressure across arterioles is greater than that across capillaries.

True/False: Factors ensuring that ventricular muscle has an adequate oxygen supply include the high oxygen extraction rate from blood circulating through the myocardium.

True - The extraction rate is about 75 per cent.

True/False: The second heart sound differs from the first heart sound in that it is heard when the ventricles are relaxing.

True - The first sound is due to ventricular systole; the second occurs during ventricu- lar relaxation when the aortic valves snap shut as ventricular pressure falls below aortic.

True/False: Aortic valve incompetence may cause hypertrophy of left ventricular muscle.

True - The greater stroke volume needed to compensate for regurgitating blood increases ventricular workload.

True/False: Increased sympathetic drive to the heart increases the coronary blood flow.

True - The increase in myocardial metabolism generates vasodilator metabolites.

True/False: The electrocardiogram shows high voltage r waves over the right ventricle in right ventricular hypertrophy.

True - The increased muscle bulk generates enhanced voltages during depolarization.

True/False: The jugular venous pressure is commonly raised in patients with mediastinal tumours.

True - The jugular veins are distended due to venous obstruction but there is little or no pulsation.

True/False: The first heart sound corresponds in time with a rise in atrial pressure.

True - The mitral and tricuspid valves bulge back into the atria.

True/False: The pressure in foot veins is lower when walking than when standing still.

True - The muscle pump in the leg decreases venous pressure.

True/False: In an adult subject standing quietly at rest, venous pressure in the thorax decreases when the subject inhales.

True - The negative intrathoracic pressure during inhalation is transmitted to the veins.

True/False: Cardiac output is normally expressed as the output of one ventricle in litres/minute.

True - The output from the left and right ventricle is the same.

True/False: Arterioles offer more resistance to flow than other vessels since they have a greater pressure drop along their length.

True - The pressure drop across the arteriolar bed is larger than in other beds indicating that arterioles are responsible for most of the circulation's vascular resistance.

True/False: Pulmonary vascular resistance is less than one-third that offered by the systemic circuit.

True - The pressure head needed to drive cardiac output through the pulmonary circuit (about 15 mmHg) is much less than that needed in the systemic circuit (about 90 mmHg).

True/False: The 'A' wave of venous pulsation in the neck is caused by atrial systole.

True - The pressure wave due to atrial contraction passes up freely into the neck.

True/False: In the estimation of cardiac output using the Fick principle pulmonary arterial blood is sampled to measure the oxygen in mixed venous blood.

True - The pulmonary artery is relatively easy to catheterize and the venous blood it contains is thoroughly mixed.

True/False: With increasing distance from the heart, arterial walls contain relatively more smooth muscle than elastic tissue.

True - The relative amount of smooth muscle increases but that of elastic tissue falls.

True/False: Systemic hypertension may be caused by excessive secretion of adrenocorticotrophic hormone (acth).

True - The resulting secretion of cortisol also causes salt and water retention.

True/False: Isometric (static) exercise differs from isotonic (dynamic) exercise in that it causes a greater increase in cardiac work for the same increase in cardiac output.

True - The rise in arterial pressure with static exercise increases cardiac work since car- diac output has to be ejected against a higher aortic pressure.

True/False: Factors ensuring that ventricular muscle has an adequate oxygen supply include the fall in coronary vascular resistance during exercise.

True - The rise in metabolic activity in the exercising heart provides the vasodilator metabolites which adapt coronary flow to supply myocardial oxygen needs.

True/False: Left ventricular failure tends to cause an increase in pulmonary capillary pressure.

True - The rise may cause pulmonary oedema if pressure exceeds the colloid osmotic pressure of the plasma proteins.

True/False: In the estimation of cardiac output by an indicator dilution technique, the primary dilution curve may be followed by a secondary rise in indicator concentration.

True - The secondary peak is due to recirculation of indicator.

True/False: When measuring blood pressure by the auscultatory method the cuff pressure at which the first sounds are heard indicate systolic pressure.

True - The sharp taps of Phase 1 are generated as the systolic pressure peaks force blood under the cuff.

True/False: In an adult subject standing quietly at rest, venous pressure in the venous sinuses of the skull are subatmospheric.

True - The sinuses are held open by their meningeal attachments and cannot collapse.

True/False: Sympathetic drive to the heart is increased in excitement.

True - The tachycardia during excitement is also reduced by Beta-blocking drugs.

True/False: The tendency for blood flow to be turbulent increases when there is a decrease in blood viscosity.

True - The tendency is inversely proportional to viscosity.

True/False: Arterial pulse contours that have varying beat-to-beat amplitude is seen in patients with atrial fibrillation.

True - The variable filling of the ventricle results in variable stroke output.

True/False: The velocity of blood flow in veins is greater than in venules.

True - The venous bed has a smaller total cross-sectional area than the venular bed.

True/False: When the AV bundle is completely interrupted, as in complete heart block, the ventricular rate falls below 50 beats/minute.

True - The ventricular intrinsic rate of beating is 30-40/minute.

True/False: The velocity of blood flow can fall to zero in the ascending aorta during diastole.

True - There is a brief period of retrograde flow as the aortic valve closes.

True/False: Local metabolic activity is the chief factor determining the rate of blood flow to the heart.

True - There is a close relationship between the work of the heart and coronary flow.

True/False: In otherwise healthy people, local tissue death follows obstruction of a renal artery.

True - There is no significant collateral circulation.

True/False: Isometric (static) exercise differs from isotonic (dynamic) exercise in that it causes a greater increase in mean arterial pressure.

True - There is relatively little fall in total peripheral resistance with static exercise.

True/False: Veins have a sympathetic vasoconstrictor innervation.

True - These modulate venous capacity.

True/False: The Purkinje tissue cells in the heart conduct impulses faster than some neurones.

True - They conduct at around 4 metres/second. Small diameter nerve fibres conduct impulses at about 1 metre per second.

True/False: Arterioles play a major role in regulating arterial blood pressure.

True - They provide most of the peripheral resistance.

True/False: The Purkinje tissue cells in the heart are responsible for the short duration of the qrs complex.

True - They spread depolarization rapidly over the entire ventricular myocardium.

True/False: Veins respond to distension by contraction of their smooth muscle.

True - This 'myogenic' response helps to limit the degree of distension.

True/False: In the denervated heart, left ventricular stroke work increases when the veins constrict.

True - This also raises cardiac filling pressure.

True/False: The first heart sound corresponds in time with a rise in ventricular pressure.

True - This closes the mitral and tricuspid valves.

True/False: In the electrocardiogram, the t wave is due to repolarization of the ventricles.

True - This electrical event corresponds with ventricular relaxation.

True/False: Increased sympathetic drive to the heart increases the slope of the frank-starling (work versus stretch) curve of the heart.

True - This enhances the force of contraction at any given filling pressure.

True/False: The Purkinje tissue cells in the heart are larger than ventricular myocardial cells.

True - This facilitates rapid conduction.

True/False: In the denervated heart, left ventricular stroke work increases when peripheral resistance rises.

True - This impedes ventricular outflow, thus increasing end-diastolic fibre length.

True/False: The net loss of fluid from capillaries in the legs is increased by arteriolar dilation.

True - This increases capillary hydrostatic pressure.

True/False: In heart failure there is sodium retention.

True - This increases extracellular fluid and hence blood volume.

True/False: Increased sympathetic drive to the heart increases the rate of diastolic depolarization in sinuatrial node cells.

True - This increases the rate of impulse generation and hence heart rate.

True/False: Narrowing of the lumen of major arteries supplying the leg is associated with pain in the calf during exercise which is relieved by rest.

True - This is 'intermittent claudication'; pain metabolites accumulate in muscle during exercise in ischaemic limbs and stimulate local pain receptors.

True/False: The jugular venous pressure is raised in patients with right ventricular failure.

True - This is an important sign in right ventricular failure; venous pulsation is present.

True/False: When the heart suddenly stops beating (cardiac asystole) artificial ventilation of the lungs should be given.

True - This is needed to maintain oxygenation of the brain.

True/False: The absolute refractory period in the ventricles is the period when the ventricles are completely inexcitable.

True - This is the definition.

True/False: Auscultation of the heart can provide evidence of mitral incompetence, if a systolic murmur is heard in the axilla.

True - This is the direction of flow of the regurgitant blood.

True/False: Ventricular filling gives rise to a third heart sound in some healthy people.

True - This low-pitched sound is sometimes heard in early diastole.

True/False: The absolute refractory period in the ventricles corresponds approximately to the period of ventricular contraction.

True - This prevents tetanic contraction of the heart.

True/False: Pulmonary vascular resistance is decreased during exercise.

True - Thus there is little rise in pulmonary arterial pressure during exercise despite the increased flow rate. Release of nitric oxide from the pulmonary vascular endo- thelium may account for the vasodilatation.

True/False: Cardiac output rises in a hot environment.

True - To meet the needs of increased metabolism and increased skin blood flow.

True/False: Murmurs (or bruits) may be detected by auscultation over dilations (aneurysms) in arteries.

True - Turbulence is set up as blood flows into the dilated segment.

True/False: Murmurs (or bruits) may be detected by auscultation over constrictions (stenoses) in arteries.

True - Turbulence is set up as blood squirts through the constricted segment.

True/False: Murmurs (or bruits) may be detected by auscultation over vessels in which there is turbulence.

True - Turbulent vibrations generate sound waves.

True/False: Sinuatrial node cells are innervated by the vagus.

True - Vagal activity slows the rate of impulse generation and thus the heart rate.

True/False: Hyperaemia in skeletal muscle during exercise is normally associated with reflex vasoconstriction in other vascular beds.

True - Vasoconstriction in kidneys, gut and skin prevent excessive falls in total periph- eral resistance.

True/False: Hardening of the arterial walls tends to raise arterial pulse wave velocity.

True - Vibrations travel faster in stiff than in lax structures.

True/False: Narrowing of the lumen of major arteries supplying the leg is associated with growth of collateral vessels.

True - When the major arteries are obstructed, collateral vessels open up to help main- tain blood flow to the ischaemic tissues.

True/False: In the measurement of forearm blood flow by venous occlusion plethysmography it is assumed that venous outflow is arrested by the collecting cuff during measurement.

True - When this is the case, the volume increase equals arterial inflow.