Quiz
Cardiovascular System- Physiology PMU- 2nd Year 2nd Sem
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Questions in this quiz (146)
1The pacemaker of the heart is normally the:
- Asino-atrial node
- Batrio-ventricular node
- Cbundle of Hiss
- Dmitral valve
- Eleft ventricle
2In electrocardiogram (ECG) the QRS complex represents:
- Adepolarisation of the atria
- Brepolarization of the atria
- Cdepolarisation of the ventricles
- Drepolarization of the ventricles
- Edelay at the AV node
3An ECG would be useful for determining a patient's:
- Aheart murmur
- Bstroke volume
- Ccardiac output
- Dblockage of conduction of electrical signals between the atria and the ventricles
- Enone of the above
4Cardiac output (C.O.) is the:
- Avolume of blood pumped per minute by both ventricles
- Bvolume of blood flowing through the systemic circulation each minute
- Cproduct of the number of heartbeats per minute and the volume pumped per beat
- Da and c
- Eb and c
5According to the Frank-Starling mechanism of the heart
- Awith each systole the left ventricle ejects a larger volume of blood then the right ventricle
- Bthe intrinsic rate of the heart's pacemaker is 100 beats per minute
- Ccardiac output increases with increased heart rate
- Dstroke volume increases with increased venous return
- Eboth ventricles contact simultaneously
6Distinguishing characteristics of the veins include the following
- Aall veins carry deoxygenated blood
- Ball veins carry blood towards the heart
- Call veins have thick elastic walls
- Da and b
- Eb and c
7During exercise, there is an increased flow of blood to
- Athe brain
- Bthe kidneys
- Cthe muscles
- Db and c
- Ea, b and c
8Which of the following does not contribute to the increased stroke volume (SV) during exercise
- Aincreased contractility of the cardiac muscle
- Bincreased venous return
- Cincreased length of filling time during diastole
- Dincreased sympathetic stimulation of the ventricular muscle
- Eincreased end-diastolic volume
9The aortic valve
- Aprevents the backflow of blood into the aorta during ventricular diastole
- Bprevents the backflow of blood into the left ventricle during ventricular diastole
- Cprevents the backflow of blood into the left ventricle during ventricular ejection
- Dprevents backflow of blood into the aorta during injection
- Ecloses when the first heart sound is heard
10In humans, blood loss causes
- Avenous constriction
- Bdecreased blood flow to the skin
- Ca fall in the cardiac output
- Dsplenic contraction
- Ea, b and c
11Angiotensin ll:
- Aas an octapeptide
- Bis produced mainly in the lungs
- Ccauses thirst
- Dstimulates the secretion of the antidiuretic hormone (ADH)
- Eall of the above
12Which of the following organs has the greatest blood flow per 100 g of tissue?
- Abrain
- Bheart muscle
- Cskin
- Dliver
- Ekidney
13If the heart rate is 70 beats/min, then cardiac output is closer to:
- A3.45 l.min-1
- B4.55 l.min-1
- C5.25 l.min-1
- D8.0 l.min-1
- E9.85 l.min-1
14The ventricles are completely depolarized during which portion of the ECG?
- APQ interval
- BQRS complex
- CQT interval
- DST segment
- ET wave
15Cardiac output (CO) of the right heart is what percentage of that of the left?
- A25%
- B50%
- C75%
- D100%
- E125%
16The action potential corresponds to which portion of the ECG?
- AP wave
- BPQ interval
- CQRS complex
- DST segment
- EQT interval
17Which effects are caused by sympathetic stimulation?
- Aincreased force of heart contraction
- Bincreased heart metabolism
- Cincreased heart conductibility
- Ddecreased excitability
- Ea, b, and c
18Which are the peculiarities of the action potential in cardiac muscle?
- Along duration (0.3 s)
- Bshort duration (0.01 s)
- Chigh amplitude
- Dplateau
- Ea, and d
19Excitation from SA node to AV node is conducted by:
- ANodal fibers
- BInternodal fibers
- CAtrial cardiac cells
- DHis bundle
- Eb, and c
20When are all four valves closed?
- Aduring isovolumetric ventricular contraction
- Bduring isovolumetric ventricular relaxation
- Cduring ventricular systole
- Dduring atrial diastole
- Ea, and b
21Effects of hypokalaemia:
- Ashort PQ interval
- Bventricular extrasystoles
- Celevated ST segments
- Dlong QRS interval
- Elong QT interval
22Hyperkalaemia:
- Acauses a prolonged QT interval
- Bprolongs the QRS
- Ccauses ST segment elevation
- Dpotentiates digoxin toxicity
- Ecauses loss of P wave
23Left ventricular end-diastolic volume is:
- A10 - 30 ml
- B30 - 50 ml
- C50 - 70 ml
- D70 - 100 ml
- E100 - 130 ml
24Local metabolic control is most important in determining flow to the:
- Askin
- Blungs
- Cskeletal muscles
- Dkidneys
- Eliver
25The atrial component of ventricular filling is:
- A5%
- B10%
- C30%
- D50%
- E80%
26The lowest intrinsic discharge activity resides in the:
- ASA node
- BAV node
- CBundle branches
- DPurkinje fibers
- EVentricular fibers
27Slowest conduction (velocity) occurs in the:
- AAtrium
- BAV node
- CBundle of His
- DPurkinje fibers
- EVentricular muscle
28Which one of the following causes vasodilatation:
- ATXA2
- BSerotonin (5-HT)
- CEndothelin
- DNeuropeptide Y
- EVIP
29The highest oxygen extraction is found in the:
- Acarotid body
- Bheart
- Ckidneys
- Dbrain
- Elungs
30The fastest conduction velocity is found in the:
- ASA node
- BAtrial muscle
- CAV-node
- DBundle of His
- EVentricular conduction system (Purkinje system)
31Oxygen consumption at rest is the highest in the:
- Abrain
- Bheart
- Cliver
- Dkidneys
- Eskeletal muscles
32Coronary blood flow is:
- Adominant in the left coronary artery in 60% of people
- Bbetter supply to subendocardium during systole
- Cbetter supply to subendocardium during diastole
- Dbetter supply to left ventricle during systole
- Eleft > right during systole
33The velocity of blood flow is greatest in:
- Acapillaries
- Bpulmonary vein during diastole
- Csmall arteries
- Dinferior vena cava
- Ethe aorta
34Arterial baroreceptor afferents:
- Areach the spinal cord via sympathetic nerves
- Butilize glycine as a neurotransmitter
- Cprimary synapse in C1 area of the medulla
- Dactivate GABA inhibitory interneurons
- Eexcite autonomic efferents in the anterolateral horn
35Isovolumetric contraction is associated with:
- Aimmediate increase in heart rate due to cardiac sympathetics
- Bcardiac output increased/unchanged
- Cincreased systolic blood pressure and decreased diastolic blood pressure
- Ddoes not work
- Edecrease stroke volume
36Baroreceptors are not located in:
- Acarotid sinus
- Bcarotid body
- Cright atrium
- Daortic arch
- Elarge veins
37The volume of blood is the greatest in the:
- Asystemic capillaries
- Blarge veins
- Csmall arteries
- Dthe liver
- Ethe lungs
38The standard ECG setting is:
- Aspeed 50 mm.s-1 50 mm/mv
- Bspeed so mm.s-1 25 mm/mV
- Cspeed 25 mm.s-1 25 mm/mV
- Dspeed 25 mm.s-1 50 mm/mV
- Enone of the above
39Long term control of tissue blood flow includes:
- Aadenosine
- Bnitric oxide
- Cchange in tissue vascularity
- Doxygen tension at the precapillary sphincter
- Ealdosterone
40Turbulence is more likely with:
- Asmall tube diameter
- Bhigh density fluid
- Cincreased tube length
- Dincreased viscosity
- Enone of the above
41The following would directly increase heart rate
- Asympathetic stimulation
- Bparasympathetic stimulation
- Cdecreased blood pressure
- Db, and c
- Enone of the above
42At any given time the largest amount of blood in the body is carried by:
- Aveins
- Bcapillary beds
- Carterioles
- Daorta
- Evena cava
43The pacemaker of the heart is:
- AAV node
- BPurkinje fibers
- CAV bundle
- DSA node
- ENone of the above
44The T wave in an ECG indicates:
- AResting potential
- BAtrial depolarization
- CSA node excitation
- DVentricle repolarization
- EPurkinje excitation
45End diastolic volume in human is about
- A140 ml
- B50 ml
- C70 ml
- D100ml
- E200ml
46Major functions of the lymphatic system are?
- Aprovide route for return of extracellular fluid
- Bact as drain off for inflammatory response
- Crender surveillance, recognition , and protection against foreign materials via lymphocytes, phagocytes, and antibodies
- Da, and c
- Ea, b, and c
47Blood pressure is the measure of:
- Apressure exerted by the blood on the walls of the blood vessels
- Bpressure exerted by the blood on the arteries
- Cpressure exerted by the blood on the veins
- Dpressure exerted by the blood on the aorta
- Enone of the above
48Systolic Pressure is:
- Aan average of 120 mm Hg
- Blowers steadily during ventricle systole
- Cthe highest when blood is being pumped out of the left ventricle into the aorta
- Dan average of 80 mm Hg
- Ea, and c
49The working myocardium:
- Ais a functional syncitium
- Bis comprised of cells whose cytoplasm communicates
- Cplays the role of pacemaker of the heart
- Dis comprised of cells, connected by structures that impede the ion flow
- Ereacts to threshold irritants with different number of excited fibers
50The heart rate at rest is:
- A100 - 140 beats.min-1
- B40 - 60 beats.min-1
- Capproximately 50 beats.min-1
- D60-90 beats.min-1
- E20-40 beats.min-1
51The full compensatory pause is typical of:
- Athe atrial extrasystoles only
- Bboth the atrial and the ventricular extrasystoles
- Cthe ventricular extrasystoles only
- Dextrasystoles during atrial fibrillation
- Eextrasystoles during atrial flutter
52The duration of the cardiac cycle depends on:
- Astroke volume
- Bthe time one systole to occur
- Cthe time one diastole to occur
- Dthe heart rate
- Ethe cardiac paused
53The rhythm of the heart is determined by:
- Athe bundle of His
- Bthe atrioventricular node
- Cthe sinus node
- Dthe Purkinje fibers
- Ethe Ieft and right bundle branches
54The increased heart rate is called:
- Atachipnoe
- Bbradycardia
- Catrial fibrillation
- Datrial flutter
- Etachycardia
55When the rhythm is determined by the AV node, the heart rate is:
- A60-90 beats.min-1
- B20-40 beats.min-1
- Capproximately 75 beats.min-1
- D40-60 beats.min-1
- E8-120 beats.min-1
56Automaticity is characteristic of:
- Athe cardiac muscle only
- Bthe striated muscles
- Csome neurons and smooth muscle cells
- Dall excitable tissues
- Ethe smooth muscle cells only
57The action potential of the cardiomyocytes passes through:
- Aslow depolarization and quick repolarization
- Brapid depolarization and slow repolarlzation
- Cquick de- and repolarizations
- Dslow de- and repolarizations
- Eperiod of current electrical activity, expressed as slow waves and spike potentials
58P wave of the electrocardiogram reflects:
- Arepolarization of the atria
- Bdepolarization of the ventricles
- Cdepolarization of the atria
- Dhyperpolarization of the atria
- Ethe time necessary for the impulse originating in SA. node to reach the Purkinje fibers
59Asynchronic contraction of the ventricles:
- Ais a phase of the ventricular systole
- Bis a phase of the ventricular diastole
- Cbegins with closing the S.L. valves
- Dbegins with opening the S.L. valves
- Ebegins with opening the A.V. valves
60In the complete atriovenrticular block:
- Athe conductivity at the bundle of His is fully interrupted
- Bthere is a complete independence of the atrial and ventricular ECG stages
- Cthe atrial waves indicate normal heart rate, but the rate of ventricular ones is 20-40 beats.min-1
- Dthe duration of PQ interval is 0.12-0.20 s
- Ea, b, and c
61The stroke volume of the heart at rest is:
- A60 - 90 beats.min-1
- Bapproximately 70 ml
- C5.2 l
- D0.500 I
- E100-140 mmHg
62The electrical axes of the heart is determined by:
- Athe vectorial sum of QRS complexes in the standard leads
- Bthe vectorial sum of QRS complexes in the precordial leads
- Cthe vector's direction of the electrical forces of the ventricular muscle tissue
- Dthe supine or straight position of the body
- Ethe vector's direction of the electrical forces of the atrial muscle tissue
63The augmented unipolar leads are
- A1st, 2nd and 3rd
- BaVR, aVL and aVF
- Canswers a, and b
- DV1, V2, V3, V4, V5 and V6
- Eb, and d
64The auscultation of the mitral valve is performed at:
- A2nd sternal intercostal space, right of the sternum
- B5th intercostal space, 2 cm inside of the medioclavicular line
- C4th sternal intercostal space, right of the sternum
- D2nd sternal intercostal space, left of the sternum
- E3rd sternal intercostal space, left of the sternum
65The phase 'plateau' of the cardiomyocytes action potentials is due to:
- Aoutflow of K+ from the cells
- Binflow of Na+ into the cells
- Cinflow of K+ into the cells
- Dslow inflow of Ca2+ into the cells
- Einflow of Na+ into the cells and outflow of K+ from the cells
66The extrasystoles are:
- Aincreased heart rate of 250-230 imp-min-1
- Bdisturbances in conductivity
- Cdisturbances in excitability
- Dextraordinary, only currently interrupting the cardiac rhythm, contractions of the cardiac muscle
- Ec, and d
67The electrical axes of the heart is of the indifferent type when the angle with the isoelectric line is:
- A+60 to +90 degrees
- B+30 to +60 degrees
- Cfrom -90 degrees upward
- D+30 to -30 degrees
- Efrom -30 degrees downwards
68Which of the following is not a vasoconstrictor:
- Anorepinephrine
- Bepinephrine
- Cserotonin
- Dangioitensin II
- Ekinins
69At rest the diastolic arterial pressure is:
- A90-95 mmHg
- B140-160 mmHg
- C60-90 mmHg
- D100-140 mmHg
- E75 mmHg
70Which of the following doesn't affect blood pressure:
- Acardiac output (C.O.)
- Bminute respiratory volume
- Cviscosity of blood
- Dtotal peripheral vessel resistance
- Ethe volume of blood
71Throughout the isovolumetrtc relaxation of the ventricles:
- AA.V. valves are opened, S.L. valves - opened
- BA.V. valves are closed, S.L. valves - opened
- CA.V. valves are opened, S.L. valves - closed
- DA.V. valves are closed, S.L. valves - closed
- ENone of the above
72The first heart sound is:
- Asystolic, result of the ventricular contractions
- Bsystolic, result of the A.V. valves closing
- Csystolic, result of the S.L valves closing
- Ddiastolic, result of the A.V. valves closing
- Ea, and b
73Cardiac output (C.O.) depends on:
- Avital capacity (VC)
- Bstroke volume (SV)
- Cheart rate (HR)
- Dthe preload and afterload
- Eb, c and d
74The intracardial regulation of the heart is carried out by:
- Aintegrated reflexes
- Bneural regulatory mechanisms
- Chumoral factors
- Dadaptation to changes in venous return or resistance in the aorta
- Ethe automaticlty
75The heart stops in diastole because of:
- Aincreased level of Ca2+ in the extracellular fluid
- Bincreased levels of catecholamines
- Cincreased levels of glucocorticoids
- Dincreased concentration of K+ the extracellular fluid
- Eincreased secretion of T3 and T4
76The peripheral chemoreceptors trigger:
- Apressor and depressor reflexes
- Bpressor reflexes only
- Cthe quick regulation of arterial blood pressure
- Ddepressor reflexes only
- EHering-Breuer reflex
77The pulse pressure is:
- Acloser in value to the systolic than to the diastolic pressure
- Bmean arithmetic of systolic and diastolic pressures
- Ccloser in value to the diastolic than to the systolic pressure
- Dthe difference between systolic and diastolic pressure
- Eone third of the mean arterial pressure
78The cardiovascular center is situated in:
- Ahypothalamus
- Bmesencephalon
- Cthe cortex
- Dmedulla oblongata
- EC8 - Th1-2 spinal cord segments
79In the pulmonary circulation blood leaves the:
- Aright ventricle and goes directly to the aorta
- Bright ventricle and moves to the lungs
- Cright atrium and goes directly to the left ventricle
- Dright atrium and goes directly to the lungs
- Eleft ventricle and moves to the lungs
80In the systemic circulation, blood leaves the:
- Aleft ventricle and goes directly to the aorta
- Bright ventricle and goes directly to the aorta
- Cright ventricle and moves to the lungs
- Dlungs and moves to the left atrium
- Eright atrium and goes directly to the lungs
81The cardiac cycle includes all of the following events except:
- Athe movement of impulses from the SA node to all regions of the heart wall
- Bthe closing and opening of the heart valves during each heart beat
- Cthe number of times the heart beats in one minute
- Dthe changes in pressure gradients in all chambers of the heart
- Ethe changes in blood volume in all chambers of the heart
82Which of the following chemicals does not regulate blood pressure?
- AADH
- BAtrial natriuretic peptide
- CAngiotensin II
- DNitric acid
- EEpinephrine
83Exchange of nutrients and gases between the blood and tissue cells is the main function of:
- Aarterioles
- Barteries
- Cveins
- Dcapillaries
- Evenules
84Arterial blood pressure increases in response to all but which of the following?
- Aincreasing stroke volume
- Bincreasing heart rate
- Crising blood volume
- Dfalling blood volume
- Eall of the above
85The inferior vena cava brings blood from the lower regions of the body empties into the:
- Aleft atrium
- Bright atrium
- Caorta
- Dleft ventricle
- Eright ventricle
86The pacemaker of the heart is the;
- APurkinje fibers
- BThe bundle branches
- CBundle of His
- DAV node
- ESA node
87The tricuspid valve is located between the:
- Aright and left atria
- Bright and left ventricles
- Cright atrium and right ventricle
- Dleft atrium and left ventricle
- Eright ventricle and the aorta
88When the mitral valve closes, it prevents the backflow of blood from the:
- Aleft atrium into the left ventricle
- Bleft ventricle into the left atrium
- Cright atrium into the right ventricle
- Dleft ventricle into the aorta
- Eright ventricle into the pulmonary trunk
89The vessels that carry oxygen to the myocardial cells are called:
- Aaortic arteries
- Bpulmonary arteries
- Cpulmonary veins
- Dcoronary veins
- Ecoronary arteries
90The myocardium functions as a functional syncytium due to:
- Athe presence of striations in the myocardium
- Bbranching of myocardlal cells
- Cthe presence of gap junctions
- Dthe presence of desmosomes
- Ehigher concentration of Ca2+
91Autorhythmic cardiac cells are found In all the following location except the:
- ASA node
- BInteratrial septum
- CPurkinje cells
- DAV node
- EHis bundle
92Coronary blood flow to the left ventricle increases during:
- Aearly systole
- Bmyocardial hypoxia
- Chypothermia
- Dstimulation of parasympathetic nerves in the heart
- EAV block
93Local metabolic activity is the chief factor determining the rate of blood flow to the:
- Aheart
- Bskin
- Cglands
- Dlung
- Ekidney
94The pressure:
- Adrop along large veins is similar to that along large arteries
- Bdrop across the hepatic penal bed is similar to that across the splenic vascular bed
- Cin the hepatic portal vein exceeds that in the inferior vena cava
- Ddrop across the vascular bed in the foot is greater when a subject is in the vertical than when he is in the horizontal position
- Ein foot veins is higher when walking than when standing still
95The second heart sound differs from the first heart sound in that it is
- Arelated to turbelence set up by valve closure
- Blonger lasting than the first sound
- Chigher in frequency
- Doccasionally in split
- Eheard when the ventricles are contracting
96Pulmonary vascular resistance is
- Ais equal to that offered by the systemic circuit
- Bdecreased when alveolar oxygen pressure fails
- Cexpressed in units of volume flow per unit time per unit pressure gradients
- Ddecreased during exercise
- Eregulated reflexvely by sympathetic vasoconstrictor nerves
97Veins:
- Acontain most of the blood volume
- Bhave a histaminergic vasodilator innervation
- Creceive nutrition from vas vasorum arising from their lumen
- Drespond to distension by dilation of their smooth muscle
- Edo not contain valves
98In the heart:
- Athe left atrial wall is about three times thicker than the right atrial wall
- Bsystolic contraction normally begins in the left atrium
- Cexcitation spreads directly from atrial muscle cells to ventricular muscle cells
- Datrial and ventricular muscle contracts simultaneously in systole
- Ethe contracting ventricles shorten from apex to base
99When measuring blood pressure by the auscultatory method:
- Athe sounds that are heard are generated in the heart
- Bthe cuff pressure at which the first sounds are heard indicate systolic pressure
- Cthe cuff pressure at which the loudest sounds are heard indicate diastolic pressure
- Dsystolic pressure estimations tend to be lower than those made by the palpatory method
- Ewider cuff's are required for smaller arms
100The absolute refractory period in the ventricles:
- Ais the period when the ventricles are completely still excitable
- Bcorresponds to the period of ventricular depolarization
- Ccorresponds approximately to the period of ventricular relaxation
- Dis shorter than the corresponding period in atrial muscle
- Edecreases during parasympathetic stimulation of the heart
101Vascular resistance:
- Aincreases by 50 per cent When the vascular radius is halved
- Bis related to the thickness of the wall of the vessel
- Cis related to the vessel’s length
- Dis affected by blood Hb concentration
- Eis greater in the capillary bed than in the arteriolar bed
102Sympathetic drive to the heart is increased:
- Ain exercise
- Bin relaxed position
- Cin normotension
- Dwhen parasympathetic drive is decreased
- Eduring a vasovagal attack
103Hyperaemia in skeletal muscle during exercise is normally associated with:
- Arelease of sympathetic vasoconstrictor tone in the exercising muscles
- Bcapillary dilation due to relaxation of capillary smooth muscle
- Ca fall in arterial pressure
- Dreflex vasoconstriction in other vascular beds
- Ean increase in venous pressure
104Sinuatrial node cells are:
- Afound in both atria
- Binnervated by the somatic nerves
- Cunable to generate impulses when completely denervated
- Dconnected to the AV node by fine bundles of purkinje tissue
- Eable to generate impulses because their membrane potential is unstable
105The first heart sound corresponds in time with:
- Aclosure of the aortic and pulmonary valves
- Bthe P wave of the electrocardiogram
- Ca decline in atrial pressure
- Da rise in ventricular pressure
- Ethe A wave in central venous pressure
106The velocity of blood flow:
- Ain capillaries is low because they offer high resistance to flow
- Bin veins is greater than in venules
- Ccan fall to zero in the ascending aorta during systole
- Dis lower towards the centre of large blood vessels than at the periphery
- Ein the circulation falls as the haematocrit falls
107The strength of contraction of left ventricular muscle increases when:
- Aend-diastolic ventricular filling pressure
- Bserum potassium levels rise
- Cblood calcium levels fall
- Dblood magnesium levels fall
- Eperipheral resistance is decreased
108During isometric ventricular contraction:
- Athe entry and exit valves of the ventricle are closed
- Bpressure in the aorta rises
- Cpressure in the atria falls
- Dleft coronary blood flow is going up
- Ethe rate of rise in pressure is greater in the right than in the left ventricle
109Cardiac output:
- Ais normally expressed as the output of one ventricle in liters/minute
- Bis about 2.0 l at rest
- Cis about 10.0 l at rest
- Drises in a cold environment
- Edoes not increase in exercise following denervatlon of the heart
110In the brachial artery:
- APulse waves travel at the same velocity as blood
- BPulse pressure falls with decreasing elasticity of the wall
- CPressure rises markedly when the artery is occluded distally
- DPressure falls when the arm is raised above head level
- EPulse pressures have a smaller amplitude than aortic pulse pressures
111Arterioles offer more resistance to flow than other vessels since they have:
- Athicker muscular walls
- Bricher sympathetic innervation
- Csmaller internal diameters
- Da smaller total cross-sectional area
- Ea greater pressure drop along their length
112In the denervated heart, left ventricular stroke work increases when:
- Athe end-diastolic length of the ventricular fibres increase
- Bperipheral resistance decreases
- Cblood volume falls
- Dright ventricular output decreases
- Ethe veins dilate
113With increasing distance from the heart, arterial:
- Awalls contain relatively more smooth muscle than elastic tissue
- Bflow has a greater tendency to be turbulent
- Cmean pressure tends to decrease slightly
- Dpulse pressure tends to increase slightly
- EpO2 falls appreciably
114In the estimation of cardiac output using the Fick principle:
- Apulmonary blood flow is measured
- Bthe pO2 of arterial and mixed venous blood are measured
- Coxygen uptake is estimated from alveolar pO2 measurements
- Dpulmonary arterial blood is sampled to measure the oxygen in venous blood
- Epulmonary venous blood is sampled to measure the oxygen in arterial blood
115Systemic hypertension may be caused by:
- Ahypoxia due to chronic respiratory failure
- Bexcessive secretion of aldosterone
- Cexcessive secretion of insulin
- Dmyocardial thickening (hypertrophy) of the left ventricle
- Ethe rapid cardiac action of ventricular fibrillation
116Peripheral differs from central circulatory failure in that:
- Ahypovolaemia is unusual
- Bit leads to underperfusion of the tissues
- Ccardiac output is usually normal
- Dcentral venous pressure is high
- Eventricular function is usually normal
117In atrial fibrillation:
- Athe electrocardlagram shows no evidence of atrial activity
- Bventricular rate is lower than atrial rate
- Crespiratory sinus arrhythmia can usually be seen
- Dthe ventricular rate is higher than atrial rate
- Ethe QRS complexes have an abnormal configuration
118Pain due to poor coronary blood flow (angina) may be relieved by:
- ACutting the parasympathetic nerve trunks supplying the heart
- BInfecting CaCl2
- CProviding the patient with a cold environment
- Dβ-adrenoceptor stimulating drugs
- EDrugs causing peripheral vasodilation
119Aortic valve incompetence may cause:
- Aincrease in arterial pulse pressure
- Bsystolic murmurs in the aortic valve area
- Chypertrophy of right ventricular muscle
- Ddecreased myocardial blood flow
- Eright ventricular failure
120Ventricular extrasystoles:
- Aare usually associated with a normal QRS complex
- Bfrom the same focus have similar QRS complexes
- Cusually occur following a compensatory pause
- Dcan‘t be detected by ECG
- Eindicate serious heart disease
121Pulmonary embolism (blood clots impacting in lung blood vessels) usually decreases:
- Apulmonary vascular resistance
- Bleft atrial pressure
- Cright atrial pressure
- Dventilation to perfusion ratios in the affected lung
- EpO2 in pulmonary venous blood
122Hardening of the arterial walls tends to raise:
- AArterial compliance
- BSystolic arterial pressure
- CDiastolic arterial pressure
- DPeripheral resistance
- EThe frequency of breathing
123Left ventricular failure tends to cause an increase in:
- Aright atrial pressure
- BIeft ventricular ejection fraction
- Cpulmonary capillary pressure
- Dlung compliance
- Epulmonary oedema when the patient stands up
124In otherwise healthy people, local tissue death follows obstruction of:
- Aan internal carotid artery
- Ba renal artery
- Ca femoral artery
- Da brachial artery
- Ethe hepatic portal vein
125The part of the circulation pumping blood to and from the lungs is known as the _____ circulation.
- Asystemic
- Bpulmonary
- Ccoronary
- Drespiratory
- Ehepatic
126The plateau phase of the action potential in contractile myocardiocytes is due to:
- Athe slow movement of Na+ across the cell membrane
- Bthe influx of Ca2+
- Cthe increased membrane permeability to K+
- Dthe increased membrane permeability to Na+
- Ea decrease in Ca2+ diffusing across membrane
127The valve between the right ventricle and the vessel that leaves it is the _____ valve.
- Atricuspid AV
- Bbicuspid AV
- Cmitral
- Dpulmonary semilunar
- Eaortic semilunar
128If the connections between the parasympathetic division of the ANS and the heart were cut, then
- Aheart rate would decrease
- Bstroke volume would decrease
- Ccardiac output would decrease
- Dheart rate would increase
- Eheart activity would remain unchanged
129Fenestrated capillaries:
- Ahave pores in their walls
- Bare located in most tissue
- Cpermit only one-way exchange of materials
- Dhave a layer of smooth muscle in their walls
- Eare found in the liver and kidneys
130Absolute refractory period in the heart:
- Acorresponds to the duration of relaxation
- Blasts till half of cardiac contraction
- Cshorter than refractory period in skeletal muscle
- Dlasts till cardiac contraction
- Elast only 10 ms
131First heart sound occurs during the period of:
- Aisometric relaxation
- Bisotonic relaxation
- Cisovolumetric contraction
- Disovolumetric relaxation
132Which of these vessels does not have sympathetic control:
- Acerebral
- Bsplanchnic
- Ccardiac
- Dcutaneous
- Emuscle
133Blood brain barrier is made up of:
- Aastrocytes
- Boligodendrocytes
- Coligodendroglia
- Dmicroglia
- Eothers
134Positive bathmotropic effect on heart is produced by:
- Astimulation of vagus nerve
- Bstimulation of sympathetic nerves
- Catropin
- Dsectioning of vagus
- EK+
135Which of the following conducting systems has the slowest conducting velocity:
- ASA node
- BAtrial muscle
- CPurkinje fibres
- DAV node
- EHiss bundle
136In heart, within physiological limits the force of contraction is directly proportional to the:
- APacemaker activity
- BAV nodal delay
- CInitial length of the cardiac muscle
- DRespiratory rate
- EST-segment
137The diacrotic notch on aortic pressure curve is caused by:
- Aclosure of mitral valve
- Bclosure of tricuspid valve
- Cclosure of atrial valve
- Dclosure of pulmonary valve
- Eopening the atrial valve
138The PR interval of ECG corresponds to:
- Aventricular repolarization
- Batrial repolarization and conduction through AV node
- Crepolarization of AV node and bundle of His
- Ddepolarization of SA node
139Increased vagal tone causes:
- Ahypertension
- Btachycardia
- Cbradycardia
- Dincrease in cardiac output
- Eincrease in stroke volume
140Which of the following is not increased during exercise;
- Astroke volume
- Btotal peripheral resistance
- Csystolic BP
- Dheart rate
- Emuscle blood flow
141Which of the following takes longest time to return to normal after 1L of blood is removed from a normal individual:
- Anumber of RBC in peripheral blood
- Bplasma volume
- Crenin secretion
- Dblood pressure
- Enumber of WBC in peripheral blood
142In a patient with mitral stenosis one would expect to hear:
- Acontinuous murmur
- Ba systolic murmur loudest over the base of heart
- Ca diastolic murmur loudest over the apex of heart
- Da diastolic murmur loudest over the base of heart
- Esystolic murmur over the apex of heart
143The ‘S' wave in ECG is below isoelectric line because of:
- Arepolarization of ventricles
- Bchange in direction of the impulse when the base of the ventricles are getting depolarised
- Cdepolarisation of apex of heart
- Drepolarisation of apex of heart
- Edepolarisation of atria
144Lymph flow from the foot is:
- Aincreased when an individual rises from the supine to standing position
- Bincreased by massaging the foot
- Cincreased when capillary permeability is decreased
- Ddecreased by exercise
- Edecreased by massaging the foot
145The "T" wave in ECG is above the isoelectric line because of:
- Adepolarisation of ventricles
- Bdepolarisation of bundle of His
- Cchange in the direction of repolarisation from the wave of depolarization of the ventricles
- Drepolarisation of purkinje fibres
- Edepolarisation of atria
146Restoration of the blood volume after haemorrhage is aided by:
- Acontraction of venous reservoirs
- Ba fall in capillary pressure in certain vascular beds
- Carteriolar vasodilation
- Dmobilization of intracellular fluid into the circulation
- Ein increase in the osmotic pressure of the plasma proteins
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- Cardiovascular System- Physiology PMU- 2nd Year 2nd Sem
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