Cardiovascular System MCQs

The primary pacemaker of the heart at physiological conditions is:

a) sino-atrial node

b) atrio-ventricular node

c) bundle of His

d) mitral valve

e) left ventricle

a) sino-atrial node

Currents caused by opening of which of the following channels contribute to the repolarization phase of the ventricular cardyomocytes action potential:

a) Na+ channels

b) Cl- channels

c) Ca2+ channel

d) K+ channels

e) HCO3- channels

d) K+ channels

In second degree atrio ventricular block:

a) the ventricular rate is lower than the atrial rate

b) the ventricular ECG complexes are distorted

c) there is a high incidence of ventricular tachycardia

d) stroke volume is decreased

e) cardiacoutput is increased.

a) the ventricular rate is lower than the atrial rate

On the electrocardiogram (ECG), the QRS complex reflects:

a) depolarization of the atria

b) repolarization of the atria

c) depolarization of the ventricles

d) repolarization of the ventricles

e) delay at the AV node

c) depolarization of the ventricles

An ECG would be useful for determining a patient's:

a) heart murmur

b) stroke volume

c) cardiac output

d) blockage of electrical impulses conduction from atria to ventricles

e) end diastolic volume

d) blockage of electrical impulses conduction from atria to ventricles

According to the Frank-Starling mechanism:

a) with each systole the left ventricle ejects a larger volume of blood then the right ventricle

b) the intrinsic rate ofthe heart's pacemaker is 100 beats perminute

c) cardiac output increases with increased heart rate

d) stroke volume increases in directly proportional manner to the increase of the venous return

e) both ventricles contract simultaneously

d) stroke volume increases in directly proportional manner to the increase of the venous return

Within protodiastole of the ventricles:

a) A-V valves are opened, S-L valves closed

b) A-V and S-L valves are closed

c) A-V and S-L valves are opened

d) A-V valves are closed, S-L valves are closing

e) none of the upper mentioned is correct

d) A-V valves are closed, S-L valves are closing

The heart:

a) has no genetic mechanisms for self excitation

b) is an organ characterized by automaticity

c) has no intrinsic mechanisms for adaptation to the changing demands of the organism

d) has stroke volume directly proportional to the afterload e) has stroke volume inversely proportional to the preload

b) is an organ characterized by automaticity

During isovolumetric contraction:

a) A-V valves are opened, S-L valves are opened

b) A-V valves are closed, S-L valves are opened

c) A-V valves are opened, S-L valves are closed

d) A-V valves are closed, S-L valves are closed

e) sometimes A-V valves are opened, sometimes closed, depending on the end-diastolic volume (EDV)

d) A-V valves are closed, S-L valves are closed

The aortic valve:

a) prevents the backflow of blood into the aorta during ventricular diastole

b) prevents the backflow of blood to the left ventricle during the ventricular diastole

c) prevents the backflow of blood into the left ventricle during ventricular ejection

d) prevents the backflow of blood into the aorta during ejection

e) closes when the first heart sound is heard

b) prevents the backflow of blood to the left ventricle during the ventricular diastole

The cardiac index:

a)is 5,25L per 1m^2 body surface area

b) doesn't depend on the body surface area

c) is 3,5L per 1m^2 body surface area

d) doesn't depend on the height of the individual

e) doesn't depend on the body mass of the individual

c) is 3,5L per 1m^2 body surface area

The heart sounds:

a) express the arterial wall fluctuations synchronous with the cardiac performance

b) register the cardyomyocytes bielectrical activity during the cardiac cycle

c) reflect the volume of blood, which the heart ejects in the large and small circle per minute

d) are registered and analyzed via auscultation and phonocardiography

e) are registered via phlebography

d) are registered and analyzed via auscultation and phonocardiography

Which of the following organs has the greatest blood flow per 100 g of tissue?

a) brain

b) heart muscle

c) skin

d) liver

e) kidney

e) kidney

If the heart rate is 70 bpm the cardiac output is closer to:

a) 3.45 l/min

b) 4.55 l/min

c) 5.25 l/min

d) 8.0 l/min

e) 9.85 l/min

c) 5.25 l/min

Which of ECG elements reflects the so called conduction time?

a) PQ interval

b) ORS complex

c) QT interval

d) ST segment

e) T wave

a) PQ interval

What percentage is the Cardiac Output (C.O.) of the right heart of that of the left? a) 25 %

b) 50 %

c) 75%

d) 100%

e) 125 %

d) 100%

During the ventricular filling:

a) A-V valves are opened, S-L valves are opened

b) A-V valves are closed,S-L valves are opened

c) A-V valves are opened, S-L valves are closed

d) A-V valves are closed, S-L valves are closed

e) there is no correct answer

c) A-V valves are opened, S-L valves are closed

In complete atrioventricular block:

a) fainting may occur because the atria are unable to pump blood into the ventricles

b) ventricular fibrillation is common

c) the atrial rate is lower than the ventricular rate

d) the atrial rate is the same as the ventricular rate

e) fainting may occur because of the low ventricular rate (20-40 bpm)

e) fainting may occur because of the low ventricular rate (20-40 bpm)

The left ventricular performance is substantially greater then that performed by the right ventricle because:

a) the contraction is slower

b) the afterload is greater

c)the stroke volume (SV) is greater

d) the preload is greater

e) the wall is thicker

b) the afterload is greater

The ejection fraction (EF):

a) reflects stroke volume of the right ventricle end diastolic volume ratio and is expressed in percents

b) reflects stroke volume end diastolic volume ratio of the left ventricle and is expressed in percents

c) is about 40%

d) is about 70ml

e) is about 200ml

b) reflects stroke volume end diastolic volume ratio of the left ventricle and is expressed in percents

Which effect/s is/are causedby sympathetic stimulation?

a) decreased cardiac conductibility

b) decreased cardiac metabolism

c) increased strength of cardiac contraction

d) decreased excitability

e) the heart is resistant to sympathetic stimulation

c) increased strength of cardiac contraction

Which are the peculiarities of the cardiomiocytes' action potential?

a) slow waves

b) type plateau and short duration (0.01 s)

c) type spyke and short absolute refractory period

d) type plateau and prolonged duration (0.3 s)

e) lack of after potentials

d) type plateau and prolonged duration (0.3 s)

The integral of arterial pressure values during one cardiac cycle is defined as:

a) pulse pressure

b) mean arterial blood pressure

c) diastolic blood pressure

d) systolic arterial pressure

e) closer in value to the systolic blood pressure

b) mean arterial blood pressure

The duration of the cardiac cycle depends on:

a) the stroke volume

b) the time needed one systole to occur

c) the time needed one diastole to occur

d) the heart rate

e) the cardiac pause.

d) the heart rate

Hypokalaemia causes:

a) short PQ interval

b) ventricular extrasystoles

c) elevated ST segment

d) prolonged QRS interval

e) prolonged QT interval

b) ventricular extrasystoles

Hyperkalaemia:

a) causes a prolonged QT interval

b) prolongs the QRS complex

c) causes ST segment elevation

d) potentiates digoxin toxicity

e) causes lack of P wave

b) prolongs the QRS complex

The End-Systolic volume(ESV) is:

a) the volume of blood in the ventricles at the end of their diastoli

b) the volume of blood in the ventricles at the end of their systoli

c) about 130 ml at physiologic rest

d) about 70 ml at physiologic rest

e) the volume of blood each of the ventricles eject during their systoli

b) the volume of blood in the ventricles at the end of their systoli

The automatic heart rate of 20-40 imp./min is typical for the:

a) bundle of His

b) A-V node

c) sino-atrial node

d) Purkinje cells

e) left and right ventricular branches

d) Purkinje cells

The End-Diastolic volume (EDV):

a) depends on the stoke volume

b) is directly proportional to the venous return to the heart

c) doesn't depend on length and strength, developed by the ventricular myocardium

d) increases when the blood pressure in aorta increases

e) doesn't depend on atrial systole and diastole

b) is directly proportional to the venous return to the heart

In the cardiac muscle, the number of excited muscle fibers generating action potentials:

a) varies

b) is always maximal

c) depends on subtreshold stimuli

d) doesn't depend on the membrane ion permeability

e) doesn't depend on the activity of Na+/K+ pump

b) is always maximal

The slowest conduction velocity is characteristic for:

a) atria

b) Purkinje fibers

c) bundle of His

d) AV node

e) ventricular muscle

d) AV node

Effect on a- and B-adrenergic receptors has:

a) noradrenaline (norepinephrine)

b) adrenaline (epinephrine)

c) atropine

d) angiotensin II

e) serotonin

b) adrenaline (epinephrine)

The absolute refractory period of cardiomyocytes:

a) is the time the cells are refractory to stimuli never mind their strength or characteristics

b) is the time the cells are tetanized

c) is the time stimulus of superthreshold manner can trigger new action potential

d) has continuity of 30 to 50 ms

e) coresponds to their depolarization

a) is the time the cells are refractory to stimuli never mind their strength or characteristics

Nitric oxide:

a) is a vasoconstrictor

b) increases arterial pressure

c) decreases the capillary wall permeability

d) increases heartrate

e) is a local vasodilator

e) is a local vasodilator

Oxygen consumption at rest is the highest in the:

a) brain

b) heart

c) liver

d) kidneys

e) skeletal muscles

b) heart

The coronary blood flow is:

a) dominant in the left coronary artery in 60% of people

b) not decreased during systole in the left ventricle better delivered to subendocardium during systole

c) not suspended during systole in the right coronary artery

d) better delivered to left ventricle during systole

e) suspended during systole in the right coronary artery

c) not suspended during systole in the right coronary artery

The second heart sound is:

a) prolonged of low frequency and strong in intensity

b) strong, of low frequency and weak

c) short,of high frequency and weak

d) prolonged of high frequency and strong

e) short, of high frequency and strong in intensity

c) short,of high frequency and weak

If on ECG, P wave is missing, but QRS complex and T wave are normal, the actual pacemaker of the heart is:

a) SA node

b) bundle of His

c) AV node

d) Purkinje fibers

e) ventricular muscles

c) AV node

The isovolumetric contraction is:

a) a part of the ejection phase of ventricular contraction

b) a part of the ventricular contraction phase

c) part of ventricular diastole d) the rapid filling phase of ventricular diastole

e) the slow filling phase of ventricular diastole

b) a part of the ventricular contraction phase

The baroreceptors in arcus aortae and carotid artery detect changes in:

a) the systolic blood pressure

b) the diastolic blood pressure

c) the mean arterial blood pressure (MAP)

d) pCO2 in blood

e) pO2 in blood

c) the mean arterial blood pressure (MAP)

The asynchronous contraction is:

a) a phase of the ventricular systole

b) a phase of the ventricular diastole

c) starts with S-L valves closure

d) ends with S-L valves opening

e) starts with A-V valves opening

a) a phase of the ventricular systole

The standard ECG bipolar leads are:

a) aVR, aVL and aVF

b) I, II and IlI

c) V1 to V6

d) II and V2

e) all ECG leads are bipolar

b) I, II and IlI

The gradient of Gaskel:

a) states that going away from the sino-atrial node the rate of spontaneously generated impulses increases

b) determines the sino-atrial node as the potential pacemaker of the heart

c) states that the number of excited muscle fibers generating action potential is maximal

d) states that going away from the sino-atrial node the rate of spontaneously generated impulses decreases

e) is the base of the intrinsic mechanisms of the heart via which it adapts to the demands of the organism

d) states that going away from the sino-atrial node the rate of spontaneously generated impulses decreases

The peripheral chemoreceptors trigger:

a) pressor and depressor reflexes

b) only pressor reflexes

c) long term regulation of arterial blood pressure

d) only depressor reflexes

e) oculocardiac reflex

b) only pressor reflexes

The following would directly increase the heart rate:

a) sympathetic stimulation

b) parasympathetic stimulation

c) decreased blood pressure

d) H1-receptors stimulation

e) increased atrial natriuretic peptide (ANP) concentration

a) sympathetic stimulation

The long-term regulation of arterial pressure is

a) nerve-reflex

b) carried out by pressor and depressor baroreceptive reflexes

c) humoral and restores the volume of blood

d) carried out by depressor chemoreceptive reflexes

e) carried out by ventral medial hypothalamus

c) humoral and restores the volume of blood

The sympathetic postganglionic neurons innervate:

a) only atria

b) only ventricles

c) both atria and ventricles

d) only right atrium

e) only left ventricle

c) both atria and ventricles

The T wave in ECG indicates:

a) resting potential

b)atrial depolarization

c) SA node excitation

d) ventricular repolarization

e) Purkinje fibers excitation

d) ventricular repolarization

The End-Diastolic volume (EDV) is about:

a) 130 ml

b) 50 ml

c) 70 ml

d) 100 ml

e) 200 ml

a) 130 ml

Increased vagal tone causes:

a) hypertension

b) tachycardia

c) bradycardia

d) increase in cardiac output

e) increase in stroke volume

c) bradycardia

The dicrotic notch on the common carotid artery sphygmography curve is caused by the:

a) closure of mitral valve

b) closure of tricuspid valve

c) closure of aortic valve

d) closure of pulmonary valve

e) opening the atrioventricular valve

c) closure of aortic valve

For the peripheral vascular resistance of a definite region, of highest significance is the:

a) the viscosity of blood

b) the length of the vessel

c) the laminar blood flow

d) the radius of the vessel

e) the venous valves

d) the radius of the vessel

The working myocardium:

a) is a functional syncitium

b) is comprised of cells whose cytoplasm communicates

c) plays the role of pacemaker of the heart

d) is comprised of cells, connected by structures that impede the ion flow

e) reacts to threshold stimuli with different number of excited fibers

a) is a functional syncitium

The heart rate at physiologic rest is:

a) 100-140 bpm

b) 40-60 bpm

c) approximately 50 bpm

d) 60-90 bpm

e) 20 40 bpm

d) 60-90 bpm

The full compensatory pause is typical of:

a) the atrial extrasystoles only

b) both the atrial and the ventricular extrasystoles

c) the ventricular extrasystoles only

d) extrasystoles during atrial fibrillation

e) extrasystoles during atrial flutter

c) the ventricular extrasystoles only

The effect of sympathetic stimulation via B2-adrenergic receptors is:

a) vasodilation in splanchnicus

b) vasodilation of renal arterioles

c) decrease in vascular resistance and increase of blood flow in skin blood vessels

d) vasodilation in working striated muscles and coronary blood flow

e) decrease of vascular resistance and increase of blood flow through the systemic veins

d) vasodilation in working striated muscles and coronary blood flow

The valvular aparatus during the ventricular rapid ejection of the cardiac cycle is:

a) A-V valves open, S-L valves - open

b) A-V valves - open, S-L valves - closed

c) A-V valves - closed,S-L valves - closed

d) A-V valves closed, S-L valves - open

e) there iS no correct answer

d) A-V valves closed, S-L valves - open

The increased heart rate is called:

a) tachypnoea

b) bradycardia

c) atrial fibrillation

d) atrial flutter

e) tachycardia

e) tachycardia

When the actual pacemaker of the heart is AV node, the heart rate is:

a) 60-90 bpm

b) 20-40 bpm

c) approximately 75 bpm

d) 40-60 bpm

e) 8-120 bpm

d) 40-60 bpm

Automaticity is characteristic for:

a) the cardiac muscle only

b) the striated muscles

c) conduction system cells, some neurons and smooth muscle cells

d) all excitable tissues

e) the smooth muscle cells only

c) conduction system cells, some neurons and smooth muscle cells

The cardyomyocytes action potential is characterized by: a) slow depolarization and quick repolarization

b) rapid depolarization and slow repolarization

c) rapid de- and repolarizations

d) slow de- and repolarizations

e) period of current electrical activity, expressed as slow waves and spike potentials

b) rapid depolarization and slow repolarization

P wave on the ECG reflects:

a) repolarization of the atria b) depolarization of the ventricles

c) depolarization of the atria

d) hyperpolarization of the atria

e) the time necessary for the impulse originating in S.A. node to reach the Purkinje fibers

c) depolarization of the atria

The parasympathetic postganglionic neurons innervate:

a) only atria

b) only ventricles

c) both atria and ventricles

d) right atrium only

e) right ventricle only

a) only atria

Determining factor for the gradient of arterial pressure is:

a) the linear velocity of blood

b) the volume velocity of blood

c) the total vascular peripheral resistance

d) the venous pulse

e) the viscosity of blood

c) the total vascular peripheral resistance

The stroke volume of the heart at physiologic rest is:

a) 60-90 bpm

b) approximately 70ml

c) 5.2 l

d) 0.500 l

e) 100-140mmHg

b) approximately 70ml

The electrical axis of the heart is determined by:

a) the vectorial sum of QRS complexes in the standard leads

b) the vectorial sum of QRS complexes in the precordial leads

c) the vector's direction of the electrical forces of the ventricular muscle tissue

d) the supine or straight position of the body

e) the vector's direction of the electrical forces of the atrial muscle tissue

a) the vectorial sum of QRS complexes in the standard leads

The augmented unipolar leads are:

a) I, II and III

b) aVR, aVL, aVF

c) VI, V2 and V3

d) V4, V5 and V6

e) I, aVR and V1

b) aVR, aVL, aVF

The auscultation of the mitral valve is performed at:

a) II sternal intercostal space, right of the sternum

b) Vth left intercostal space, 2 cm medial to the midclavicular line

c) IVth sternal intercostal space, right of the sternum

d) IInd sternal intercostal space, left of the sternum

e) IlIrd sternal intercostal space, left of the sternum

b) Vth left intercostal space, 2 cm medial to the midclavicular line

The 'plateau'-phase of the cardiomyocytes' action potential is due to:

a) outflux of K+ from the cells

b) influx of Na+ into the cells

c) influx of K+ into the cells

d) slow influx of Ca2+ into the cells

e) influx of Na' into the cells and outflux of K' from the cells

d) slow influx of Ca2+ into the cells

The electrical axis of the heart is of indifferent type when a-angle is:

a) from +60 to +90 degrees

b) from +30 to +60 degrees

c) from -90 degrees upward

d) from +30 to -30 degrees

e) from -30 degrees downward

b) from +30 to +60 degrees

The secreted by postganglionic sympathetic neurons noradrenaline and adrenaline activate in myocardium:

a) B2 adrenergic receptors

b) M2 holinergic receptors

c) a2 adrenergic receptors

d) B1 adrenergic receptors

e) H1 receptors

d) B1 adrenergic receptors

At physiologic rest the diastolic arterial pressure is:

a)90 - 95 mmHg

b) 140 - 160 mmHg

c) 60 - 90 mmHg

d) 100 - 140 mmHg

e) 75 mmHg

c) 60 - 90 mmHg

The blood flow through microcirculation is controlled by:

a) hyperoxemia and hypocapnia

b) hypoxia and hypercapnia c) increased pH

d) lowered tissue metabolism

e) hyperoxemia and hypercholesterolemia

b) hypoxia and hypercapnia

Throughout the isovolumetric relaxation of the ventricles:

a) A-V valves are opened, S-L valves are opened

b) A-V valves are closed, S-L valves are opened

c) A-V valves are opened, S-L valves are closed

d) A-V valves are closed, S-L valves are closed

e) none of the above

d) A-V valves are closed, S-L valves are closed

The first heart sound is:

a) systolic, result of the ventricular contractions and A-V valves closing

b) systolic,result of the A-V valves opening

c) systolic, result of the S-L valves closing

d) diastolic, result of the A-V valves closing

e) diastolic, result of S-L valves closing

a) systolic, result of the ventricular contractions and A-V valves closing

Cardiac output(C.O.) depends on:

a) Vital Capacity (VC)

b) Stroke Volume (SV), Heart Rate (HR) and pre- and afterload

c) Heart Rate (HR) only

d) the preload and afterload only

e) Stroke Volume (SV) only

b) Stroke Volume (SV), Heart Rate (HR) and pre- and afterload

The intracardial regulation of the heart is carried out by:

a) integrated reflexes

b) neural regulatory mechanisms

c) humoral factors

d) adaptation to changes in venous return or in peripheral resistance

e) the automaticity

d) adaptation to changes in venous return or in peripheral resistance

The heart would stop in diastole because of:

a) increased level of Ca2+ in the extracellular fluid

b) increased levels of catecholamines

c) increased levels of glucocorticoids

d) increased concentration of K+ in the extracellular fluid (above 8 mmol/l)

e) increased secretion of T3 and T4

d) increased concentration of K+ in the extracellular fluid (above 8 mmol/l)

When the heart rate is 60 bpm, the duration of the cardiac cycle is:

a) 0.5 s

b) 0.8 s

c) 1 s

d) 0.2 s

e) 60 s

c) 1 s

The pulse pressure (PP) is:

a) closer in value to the systolic than to the diastolic pressure

b) mean arithmetic of systolic and diastolic pressures

c) closer in value to the diastolic than to the systolic pressure

d) the difference between the systolic and diastolic pressure

e) one third of the mean arterial pressure

d) the difference between the systolic and diastolic pressure

The cardiovascular center is situated in:

a) hypothalamus

b) mesencephalon

c) the cortex

d) medulla oblongata

e) C8-Th1-2 spinal cord segments

d) medulla oblongata

Via the reflex of Pavlov-Bainbridge:

a) the greater volume of blood in the pulmonary circulation leads to decreased heart rate and slight decrease in arterial pressure

b) the bigger venous return to the heart triggers tachycardia

c) the ventricular diastolic filling is limited

d) the distension of ventricles is followed by compensatory bradycardia and decrease in arterial pressure

e) the viscosity of blood decreases

b) the bigger venous return to the heart triggers tachycardia

The atrial Nat-uretic peptide:

a) is synthesized by right atrial cardiomyocytes and stimulates Na+- uresis via kidneys

b) decreases Na+-uresis via kidneys

c) is a vasoconstrictor

d) worsens the renal blood flow

e) stimulates reabsorption of water in kidneys

a) is synthesized by right atrial cardiomyocytes and stimulates Na+- uresis via kidneys

The short-term regulation of arterial pressure is:

a) humoral

b) neural

c) performed via depressor hemoreceptive reflexes

d) performed via renin-angiotensin II system

e) performed via body fluids control

b) neural

Vasopressin:

a) is secreted when arterial pressure is raised

b) is a potent vasoconstrictor

c) stimulates sodium uresis

d) stimulates diuresis

e) is vasodilator

b) is a potent vasoconstrictor

Exchange of nutrients and gases between the blood and tissue cells is the main function of the:

a) arterioles

b) arteries

c) veins

d) capillaries

e) venules

d) capillaries

In the heart, (within physiological limits) the strength of contraction is directly proportional to the:

a) pacemaker activity

b) A-V nodal delay

c) initial length of the cardiomyocytes

d) respiratory rate

e) ST-segment

c) initial length of the cardiomyocytes

Endothelins:

a) are vasodilators

b) are vasoconstrictors

c) depress migration of leucocytes

d) are stimulated by hyperoxemia and hypocholesterolemia

e) decrease intracellular concentration of Ca2+

b) are vasoconstrictors

The coronary blood vessels: a) have rich parasympathetic innervation

b) that belong to the epicardial plexus have mainly a1 adrenergic receptors and react via vasonstriction

c) that belong to the epicardial plexus have mainly B1 adrenergic receptors and react via vasodilation

d) that belong to the epicardial plexus have mainly M1 adrenergic receptors and react via vasodilation

e) that belong to the epicardial plexus have mainly M2 adrenergic receptors and react via vasoconstriction

b) that belong to the epicardial plexus have mainly a1 adrenergic receptors and react via vasonstriction

The brain blood flow:

a) is not a constant parameter

b) has unlimited pulse and volume changes

c) is constant when the mean arterial pressure is in the interval 80-180 mmHg

d) decreases when pCO2 is increased

e) increases when pO2 is increased

c) is constant when the mean arterial pressure is in the interval 80-180 mmHg

The pulse wave velocity:

a) is lowest in the small arteries at physiologic conditions

b) is one and the same in the different vascular regions

c) is highest in the small arteries at physiologic conditions

d) is highest in aorta

e) is lower in the small arteries compared to that in mid-size arteries at physiologic conditions

c) is highest in the small arteries at physiologic conditions

The rate of self excitation of the conduction system cells is:

a) highest of Purkinje fibers

b) lowest of sino-atrial node

c) lowest of Purkinje fibers

d) highest of atrio-ventricular node

e) higher of Purkinje fibers compared to these of atrio-ventricular node

c) lowest of Purkinje fibers

The myocardium functions as a functional syncytium due to:

a) striated muscle fibers

b) branching of myocardial cells

c) gap junctions (intercalated disks)

d) the presence of desmosomes

e) higher concentration of Ca2+

c) gap junctions (intercalated disks)

Positive bathmotropic effecton the heartis produced by:

a) stimulation of vagus nerve

b) stimulation of sympathetic nerves

c) atropin

d) cutting vagus

e) K+ application

b) stimulation of sympathetic nerves

At physiologic conditions, the pulmonary vascular resistance:

a) is equal to the systemic vascular resistance

b) decreases when the partial pressure of oxygen in alveli is lowered

c) is low, as the pulmonary blood vessels are short,wide and have high percentage of elastic fibers in their vascular wall

d) is higher compared to that in the systemic vascular resistance

e) decreases when the partial pressure of carbon dioxide in alveoli is increased

c) is low, as the pulmonary blood vessels are short,wide and have high percentage of elastic fibers in their vascular wall

The pulmonary valve is auscultated at:

a) IInd left intercostal space, at the sternal edge

b) IInd right intercostal space, close to sternum

c) IIIrd left intercostal space, at thesternal edge

d) IVth right intercostal space, at the sternal edge

e) Vth left intercostal space, 2 cm inwards midclavicular line

a) IInd left intercostal space, at the sternal edge

Which of the pointed factors plays key role for the effective filtration pressure at the microcirculatory unit:

a) hemodynamic pressure

b) intrapleural pressure

c) plasma protein colloid osmotic pressure

d) tissue pressure

e) interstitial colloid osmotic pressure

a) hemodynamic pressure

The second heart sound differs from the first heart sound in that it is:

a) related to turbulence set up by valve closure

b) longer lasting than the first sound

c) higher in frequency

d) occasionally split

e) heard when the ventricles are contracting

c) higher in frequency

Pulmonary vascular resistance is:

a) is equal to that offered by the systemic circuit

b) decreased when alveolar oxygen pressure falls

c) expressed in units of volume flow per unit time per unit pressure gradient

d) decreased during exercise

e) regulated reflexely by sympathetic vasoconstrictor nerves

d) decreased during exercise

Which of the vessels mentioned below are not under sympathetic control:

a) cerebral

b) splanchnic

c) cardiac

d) cutaneous

e) in the striated muscles

a) cerebral