8347547
Descripción
Test por Med Student , actualizado hace más de 1 año
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Creado por Med Student
hace alrededor de 7 años
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Pregunta 1
Pregunta
The pacemaker of the heart is normally the:
Respuesta
-
sino-atrial node
-
atrio-ventricular node
-
bundle of Hiss
-
mitral valve
-
left ventricle
Pregunta 2
Pregunta
In electrocardiogram (ECG) the QRS complex represents:
Respuesta
-
depolarisation of the atria
-
repolarization of the atria
-
depolarisation of the ventricles
-
repolarization of the ventricles
-
delay at the AV node
Pregunta 3
Pregunta
An ECG would be useful for determining a patient's:
Respuesta
-
heart murmur
-
stroke volume
-
cardiac output
-
blockage of conduction of electrical signals between the atria and the ventricles
-
none of the above
Pregunta 4
Pregunta
Cardiac output (C.O.) is the:
Respuesta
-
volume of blood pumped per minute by both ventricles
-
volume of blood flowing through the systemic circulation each minute
-
product of the number of heartbeats per minute and the volume pumped per beat
-
a and c
-
b and c
Pregunta 5
Pregunta
According to the Frank-Starling mechanism of the heart
Respuesta
-
with each systole the left ventricle ejects a larger volume of blood then the right ventricle
-
the intrinsic rate of the heart's pacemaker is 100 beats per minute
-
cardiac output increases with increased heart rate
-
stroke volume increases with increased venous return
-
both ventricles contact simultaneously
Pregunta 6
Pregunta
Distinguishing characteristics of the veins include the following
Respuesta
-
all veins carry deoxygenated blood
-
all veins carry blood towards the heart
-
all veins have thick elastic walls
-
a and b
-
b and c
Pregunta 7
Pregunta
During exercise, there is an increased flow of blood to
Respuesta
-
the brain
-
the kidneys
-
the muscles
-
b and c
-
a, b and c
Pregunta 8
Pregunta
Which of the following does not contribute to the increased stroke volume (SV) during exercise
Respuesta
-
increased contractility of the cardiac muscle
-
increased venous return
-
increased length of filling time during diastole
-
increased sympathetic stimulation of the ventricular muscle
-
increased end-diastolic volume
Pregunta 9
Pregunta
The aortic valve
Respuesta
-
prevents the backflow of blood into the aorta during ventricular diastole
-
prevents the backflow of blood into the left ventricle during ventricular diastole
-
prevents the backflow of blood into the left ventricle during ventricular ejection
-
prevents backflow of blood into the aorta during injection
-
closes when the first heart sound is heard
Pregunta 10
Pregunta
In humans, blood loss causes
Respuesta
-
venous constriction
-
decreased blood flow to the skin
-
a fall in the cardiac output
-
splenic contraction
-
a, b and c
Pregunta 11
Pregunta
Angiotensin ll:
Respuesta
-
as an octapeptide
-
is produced mainly in the lungs
-
causes thirst
-
stimulates the secretion of the antidiuretic hormone (ADH)
-
all of the above
Pregunta 12
Pregunta
Which of the following organs has the greatest blood flow per 100 g of tissue?
Respuesta
-
brain
-
heart muscle
-
skin
-
liver
-
kidney
Pregunta 13
Pregunta
If the heart rate is 70 beats/min, then cardiac output is closer to:
Respuesta
-
3.45 l.min-1
-
4.55 l.min-1
-
5.25 l.min-1
-
8.0 l.min-1
-
9.85 l.min-1
Pregunta 14
Pregunta
The ventricles are completely depolarized during which portion of the ECG?
Respuesta
-
PQ interval
-
QRS complex
-
QT interval
-
ST segment
-
T wave
Pregunta 15
Pregunta
Cardiac output (CO) of the right heart is what percentage of that of the left?
Respuesta
-
25%
-
50%
-
75%
-
100%
-
125%
Pregunta 16
Pregunta
The action potential corresponds to which portion of the ECG?
Respuesta
-
P wave
-
PQ interval
-
QRS complex
-
ST segment
-
QT interval
Pregunta 17
Pregunta
Which effects are caused by sympathetic stimulation?
Respuesta
-
increased force of heart contraction
-
increased heart metabolism
-
increased heart conductibility
-
decreased excitability
-
a, b, and c
Pregunta 18
Pregunta
Which are the peculiarities of the action potential in cardiac muscle?
Respuesta
-
long duration (0.3 s)
-
short duration (0.01 s)
-
high amplitude
-
plateau
-
a, and d
Pregunta 19
Pregunta
Excitation from SA node to AV node is conducted by:
Respuesta
-
Nodal fibers
-
Internodal fibers
-
Atrial cardiac cells
-
His bundle
-
b, and c
Pregunta 20
Pregunta
When are all four valves closed?
Respuesta
-
during isovolumetric ventricular contraction
-
during isovolumetric ventricular relaxation
-
during ventricular systole
-
during atrial diastole
-
a, and b
Pregunta 21
Pregunta
Effects of hypokalaemia:
Respuesta
-
short PQ interval
-
ventricular extrasystoles
-
elevated ST segments
-
long QRS interval
-
long QT interval
Pregunta 22
Pregunta
Hyperkalaemia:
Respuesta
-
causes a prolonged QT interval
-
prolongs the QRS
-
causes ST segment elevation
-
potentiates digoxin toxicity
-
causes loss of P wave
Pregunta 23
Pregunta
Left ventricular end-diastolic volume is:
Respuesta
-
10 - 30 ml
-
30 - 50 ml
-
50 - 70 ml
-
70 - 100 ml
-
100 - 130 ml
Pregunta 24
Pregunta
Local metabolic control is most important in determining flow to the:
Respuesta
-
skin
-
lungs
-
skeletal muscles
-
kidneys
-
liver
Pregunta 25
Pregunta
The atrial component of ventricular filling is:
Respuesta
-
5%
-
10%
-
30%
-
50%
-
80%
Pregunta 26
Pregunta
The lowest intrinsic discharge activity resides in the:
Respuesta
-
SA node
-
AV node
-
Bundle branches
-
Purkinje fibers
-
Ventricular fibers
Pregunta 27
Pregunta
Slowest conduction (velocity) occurs in the:
Respuesta
-
Atrium
-
AV node
-
Bundle of His
-
Purkinje fibers
-
Ventricular muscle
Pregunta 28
Pregunta
Which one of the following causes vasodilatation:
Respuesta
-
TXA2
-
Serotonin (5-HT)
-
Endothelin
-
Neuropeptide Y
-
VIP
Pregunta 29
Pregunta
The highest oxygen extraction is found in the:
Respuesta
-
carotid body
-
heart
-
kidneys
-
brain
-
lungs
Pregunta 30
Pregunta
The fastest conduction velocity is found in the:
Respuesta
-
SA node
-
Atrial muscle
-
AV-node
-
Bundle of His
-
Ventricular conduction system (Purkinje system)
Pregunta 31
Pregunta
Oxygen consumption at rest is the highest in the:
Respuesta
-
brain
-
heart
-
liver
-
kidneys
-
skeletal muscles
Pregunta 32
Pregunta
Coronary blood flow is:
Respuesta
-
dominant in the left coronary artery in 60% of people
-
better supply to subendocardium during systole
-
better supply to subendocardium during diastole
-
better supply to left ventricle during systole
-
left > right during systole
Pregunta 33
Pregunta
The velocity of blood flow is greatest in:
Respuesta
-
capillaries
-
pulmonary vein during diastole
-
small arteries
-
inferior vena cava
-
the aorta
Pregunta 34
Pregunta
Arterial baroreceptor afferents:
Respuesta
-
reach the spinal cord via sympathetic nerves
-
utilize glycine as a neurotransmitter
-
primary synapse in C1 area of the medulla
-
activate GABA inhibitory interneurons
-
excite autonomic efferents in the anterolateral horn
Pregunta 35
Pregunta
Isovolumetric contraction is associated with:
Respuesta
-
immediate increase in heart rate due to cardiac sympathetics
-
cardiac output increased/unchanged
-
increased systolic blood pressure and decreased diastolic blood pressure
-
does not work
-
decrease stroke volume
Pregunta 36
Pregunta
Baroreceptors are not located in:
Respuesta
-
carotid sinus
-
carotid body
-
right atrium
-
aortic arch
-
large veins
Pregunta 37
Pregunta
The volume of blood is the greatest in the:
Respuesta
-
systemic capillaries
-
large veins
-
small arteries
-
the liver
-
the lungs
Pregunta 38
Pregunta
The standard ECG setting is:
Respuesta
-
speed 50 mm.s-1 50 mm/mv
-
speed so mm.s-1 25 mm/mV
-
speed 25 mm.s-1 25 mm/mV
-
speed 25 mm.s-1 50 mm/mV
-
none of the above
Pregunta 39
Pregunta
Long term control of tissue blood flow includes:
Respuesta
-
adenosine
-
nitric oxide
-
change in tissue vascularity
-
oxygen tension at the precapillary sphincter
-
aldosterone
Pregunta 40
Pregunta
Turbulence is more likely with:
Respuesta
-
small tube diameter
-
high density fluid
-
increased tube length
-
increased viscosity
-
none of the above
Pregunta 41
Pregunta
The following would directly increase heart rate
Respuesta
-
sympathetic stimulation
-
parasympathetic stimulation
-
decreased blood pressure
-
b, and c
-
none of the above
Pregunta 42
Pregunta
At any given time the largest amount of blood in the body is carried by:
Respuesta
-
veins
-
capillary beds
-
arterioles
-
aorta
-
vena cava
Pregunta 43
Pregunta
The pacemaker of the heart is:
Respuesta
-
AV node
-
Purkinje fibers
-
AV bundle
-
SA node
-
None of the above
Pregunta 44
Pregunta
The T wave in an ECG indicates:
Respuesta
-
Resting potential
-
Atrial depolarization
-
SA node excitation
-
Ventricle repolarization
-
Purkinje excitation
Pregunta 45
Pregunta
End diastolic volume in human is about
Respuesta
-
140 ml
-
50 ml
-
70 ml
-
100ml
-
200ml
Pregunta 46
Pregunta
Major functions of the lymphatic system are?
Respuesta
-
provide route for return of extracellular fluid
-
act as drain off for inflammatory response
-
render surveillance, recognition , and protection against foreign materials via lymphocytes, phagocytes, and antibodies
-
a, and c
-
a, b, and c
Pregunta 47
Pregunta
Blood pressure is the measure of:
Respuesta
-
pressure exerted by the blood on the walls of the blood vessels
-
pressure exerted by the blood on the arteries
-
pressure exerted by the blood on the veins
-
pressure exerted by the blood on the aorta
-
none of the above
Pregunta 48
Pregunta
Systolic Pressure is:
Respuesta
-
an average of 120 mm Hg
-
lowers steadily during ventricle systole
-
the highest when blood is being pumped out of the left ventricle into the aorta
-
an average of 80 mm Hg
-
a, and c
Pregunta 49
Pregunta
The working myocardium:
Respuesta
-
is a functional syncitium
-
is comprised of cells whose cytoplasm communicates
-
plays the role of pacemaker of the heart
-
is comprised of cells, connected by structures that impede the ion flow
-
reacts to threshold irritants with different number of excited fibers
Pregunta 50
Pregunta
The heart rate at rest is:
Respuesta
-
100 - 140 beats.min-1
-
40 - 60 beats.min-1
-
approximately 50 beats.min-1
-
60-90 beats.min-1
-
20-40 beats.min-1
Pregunta 51
Pregunta
The full compensatory pause is typical of:
Respuesta
-
the atrial extrasystoles only
-
both the atrial and the ventricular extrasystoles
-
the ventricular extrasystoles only
-
extrasystoles during atrial fibrillation
-
extrasystoles during atrial flutter
Pregunta 52
Pregunta
The duration of the cardiac cycle depends on:
Respuesta
-
stroke volume
-
the time one systole to occur
-
the time one diastole to occur
-
the heart rate
-
the cardiac paused
Pregunta 53
Pregunta
The rhythm of the heart is determined by:
Respuesta
-
the bundle of His
-
the atrioventricular node
-
the sinus node
-
the Purkinje fibers
-
the Ieft and right bundle branches
Pregunta 54
Pregunta
The increased heart rate is called:
Respuesta
-
tachipnoe
-
bradycardia
-
atrial fibrillation
-
atrial flutter
-
tachycardia
Pregunta 55
Pregunta
When the rhythm is determined by the AV node, the heart rate is:
Respuesta
-
60-90 beats.min-1
-
20-40 beats.min-1
-
approximately 75 beats.min-1
-
40-60 beats.min-1
-
8-120 beats.min-1
Pregunta 56
Pregunta
Automaticity is characteristic of:
Respuesta
-
the cardiac muscle only
-
the striated muscles
-
some neurons and smooth muscle cells
-
all excitable tissues
-
the smooth muscle cells only
Pregunta 57
Pregunta
The action potential of the cardiomyocytes passes through:
Respuesta
-
slow depolarization and quick repolarization
-
rapid depolarization and slow repolarlzation
-
quick de- and repolarizations
-
slow de- and repolarizations
-
period of current electrical activity, expressed as slow waves and spike potentials
Pregunta 58
Pregunta
P wave of the electrocardiogram reflects:
Respuesta
-
repolarization of the atria
-
depolarization of the ventricles
-
depolarization of the atria
-
hyperpolarization of the atria
-
the time necessary for the impulse originating in SA. node to reach the Purkinje fibers
Pregunta 59
Pregunta
Asynchronic contraction of the ventricles:
Respuesta
-
is a phase of the ventricular systole
-
is a phase of the ventricular diastole
-
begins with closing the S.L. valves
-
begins with opening the S.L. valves
-
begins with opening the A.V. valves
Pregunta 60
Pregunta
In the complete atriovenrticular block:
Respuesta
-
the conductivity at the bundle of His is fully interrupted
-
there is a complete independence of the atrial and ventricular ECG stages
-
the atrial waves indicate normal heart rate, but the rate of ventricular ones is 20-40 beats.min-1
-
the duration of PQ interval is 0.12-0.20 s
-
a, b, and c
Pregunta 61
Pregunta
The stroke volume of the heart at rest is:
Respuesta
-
60 - 90 beats.min-1
-
approximately 70 ml
-
5.2 l
-
0.500 I
-
100-140 mmHg
Pregunta 62
Pregunta
The electrical axes of the heart is determined by:
Respuesta
-
the vectorial sum of QRS complexes in the standard leads
-
the vectorial sum of QRS complexes in the precordial leads
-
the vector's direction of the electrical forces of the ventricular muscle tissue
-
the supine or straight position of the body
-
the vector's direction of the electrical forces of the atrial muscle tissue
Pregunta 63
Pregunta
The augmented unipolar leads are
Respuesta
-
1st, 2nd and 3rd
-
aVR, aVL and aVF
-
answers a, and b
-
V1, V2, V3, V4, V5 and V6
-
b, and d
Pregunta 64
Pregunta
The auscultation of the mitral valve is performed at:
Respuesta
-
2nd sternal intercostal space, right of the sternum
-
5th intercostal space, 2 cm inside of the medioclavicular line
-
4th sternal intercostal space, right of the sternum
-
2nd sternal intercostal space, left of the sternum
-
3rd sternal intercostal space, left of the sternum
Pregunta 65
Pregunta
The phase 'plateau' of the cardiomyocytes action potentials is due to:
Respuesta
-
outflow of K+ from the cells
-
inflow of Na+ into the cells
-
inflow of K+ into the cells
-
slow inflow of Ca2+ into the cells
-
inflow of Na+ into the cells and outflow of K+ from the cells
Pregunta 66
Pregunta
The extrasystoles are:
Respuesta
-
increased heart rate of 250-230 imp-min-1
-
disturbances in conductivity
-
disturbances in excitability
-
extraordinary, only currently interrupting the cardiac rhythm, contractions of the cardiac muscle
-
c, and d
Pregunta 67
Pregunta
The electrical axes of the heart is of the indifferent type when the angle with the isoelectric line is:
Respuesta
-
+60 to +90 degrees
-
+30 to +60 degrees
-
from -90 degrees upward
-
+30 to -30 degrees
-
from -30 degrees downwards
Pregunta 68
Pregunta
Which of the following is not a vasoconstrictor:
Respuesta
-
norepinephrine
-
epinephrine
-
serotonin
-
angioitensin II
-
kinins
Pregunta 69
Pregunta
At rest the diastolic arterial pressure is:
Respuesta
-
90-95 mmHg
-
140-160 mmHg
-
60-90 mmHg
-
100-140 mmHg
-
75 mmHg
Pregunta 70
Pregunta
Which of the following doesn't affect blood pressure:
Respuesta
-
cardiac output (C.O.)
-
minute respiratory volume
-
viscosity of blood
-
total peripheral vessel resistance
-
the volume of blood
Pregunta 71
Pregunta
Throughout the isovolumetrtc relaxation of the ventricles:
Respuesta
-
A.V. valves are opened, S.L. valves - opened
-
A.V. valves are closed, S.L. valves - opened
-
A.V. valves are opened, S.L. valves - closed
-
A.V. valves are closed, S.L. valves - closed
-
None of the above
Pregunta 72
Pregunta
The first heart sound is:
Respuesta
-
systolic, result of the ventricular contractions
-
systolic, result of the A.V. valves closing
-
systolic, result of the S.L valves closing
-
diastolic, result of the A.V. valves closing
-
a, and b
Pregunta 73
Pregunta
Cardiac output (C.O.) depends on:
Respuesta
-
vital capacity (VC)
-
stroke volume (SV)
-
heart rate (HR)
-
the preload and afterload
-
b, c and d
Pregunta 74
Pregunta
The intracardial regulation of the heart is carried out by:
Respuesta
-
integrated reflexes
-
neural regulatory mechanisms
-
humoral factors
-
adaptation to changes in venous return or resistance in the aorta
-
the automaticlty
Pregunta 75
Pregunta
The heart stops in diastole because of:
Respuesta
-
increased level of Ca2+ in the extracellular fluid
-
increased levels of catecholamines
-
increased levels of glucocorticoids
-
increased concentration of K+ the extracellular fluid
-
increased secretion of T3 and T4
Pregunta 76
Pregunta
The peripheral chemoreceptors trigger:
Respuesta
-
pressor and depressor reflexes
-
pressor reflexes only
-
the quick regulation of arterial blood pressure
-
depressor reflexes only
-
Hering-Breuer reflex
Pregunta 77
Pregunta
The pulse pressure is:
Respuesta
-
closer in value to the systolic than to the diastolic pressure
-
mean arithmetic of systolic and diastolic pressures
-
closer in value to the diastolic than to the systolic pressure
-
the difference between systolic and diastolic pressure
-
one third of the mean arterial pressure
Pregunta 78
Pregunta
The cardiovascular center is situated in:
Respuesta
-
hypothalamus
-
mesencephalon
-
the cortex
-
medulla oblongata
-
C8 - Th1-2 spinal cord segments
Pregunta 79
Pregunta
In the pulmonary circulation blood leaves the:
Respuesta
-
right ventricle and goes directly to the aorta
-
right ventricle and moves to the lungs
-
right atrium and goes directly to the left ventricle
-
right atrium and goes directly to the lungs
-
left ventricle and moves to the lungs
Pregunta 80
Pregunta
In the systemic circulation, blood leaves the:
Respuesta
-
left ventricle and goes directly to the aorta
-
right ventricle and goes directly to the aorta
-
right ventricle and moves to the lungs
-
lungs and moves to the left atrium
-
right atrium and goes directly to the lungs
Pregunta 81
Pregunta
The cardiac cycle includes all of the following events except:
Respuesta
-
the movement of impulses from the SA node to all regions of the heart wall
-
the closing and opening of the heart valves during each heart beat
-
the number of times the heart beats in one minute
-
the changes in pressure gradients in all chambers of the heart
-
the changes in blood volume in all chambers of the heart
Pregunta 82
Pregunta
Which of the following chemicals does not regulate blood pressure?
Respuesta
-
ADH
-
Atrial natriuretic peptide
-
Angiotensin II
-
Nitric acid
-
Epinephrine
Pregunta 83
Pregunta
Exchange of nutrients and gases between the blood and tissue cells is the main function of:
Respuesta
-
arterioles
-
arteries
-
veins
-
capillaries
-
venules
Pregunta 84
Pregunta
Arterial blood pressure increases in response to all but which of the following?
Respuesta
-
increasing stroke volume
-
increasing heart rate
-
rising blood volume
-
falling blood volume
-
all of the above
Pregunta 85
Pregunta
The inferior vena cava brings blood from the lower regions of the body empties into the:
Respuesta
-
left atrium
-
right atrium
-
aorta
-
left ventricle
-
right ventricle
Pregunta 86
Pregunta
The pacemaker of the heart is the;
Respuesta
-
Purkinje fibers
-
The bundle branches
-
Bundle of His
-
AV node
-
SA node
Pregunta 87
Pregunta
The tricuspid valve is located between the:
Respuesta
-
right and left atria
-
right and left ventricles
-
right atrium and right ventricle
-
left atrium and left ventricle
-
right ventricle and the aorta
Pregunta 88
Pregunta
When the mitral valve closes, it prevents the backflow of blood from the:
Respuesta
-
left atrium into the left ventricle
-
left ventricle into the left atrium
-
right atrium into the right ventricle
-
left ventricle into the aorta
-
right ventricle into the pulmonary trunk
Pregunta 89
Pregunta
The vessels that carry oxygen to the myocardial cells are called:
Respuesta
-
aortic arteries
-
pulmonary arteries
-
pulmonary veins
-
coronary veins
-
coronary arteries
Pregunta 90
Pregunta
The myocardium functions as a functional syncytium due to:
Respuesta
-
the presence of striations in the myocardium
-
branching of myocardlal cells
-
the presence of gap junctions
-
the presence of desmosomes
-
higher concentration of Ca2+
Pregunta 91
Pregunta
Autorhythmic cardiac cells are found In all the following location except the:
Respuesta
-
SA node
-
Interatrial septum
-
Purkinje cells
-
AV node
-
His bundle
Pregunta 92
Pregunta
Coronary blood flow to the left ventricle increases during:
Respuesta
-
early systole
-
myocardial hypoxia
-
hypothermia
-
stimulation of parasympathetic nerves in the heart
-
AV block
Pregunta 93
Pregunta
Local metabolic activity is the chief factor determining the rate of blood flow to the:
Respuesta
-
heart
-
skin
-
glands
-
lung
-
kidney
Pregunta 94
Pregunta
The pressure:
Respuesta
-
drop along large veins is similar to that along large arteries
-
drop across the hepatic penal bed is similar to that across the splenic vascular bed
-
in the hepatic portal vein exceeds that in the inferior vena cava
-
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
-
in foot veins is higher when walking than when standing still
Pregunta 95
Pregunta
The second heart sound differs from the first heart sound in that it is
Respuesta
-
related to turbelence set up by valve closure
-
longer lasting than the first sound
-
higher in frequency
-
occasionally in split
-
heard when the ventricles are contracting
Pregunta 96
Pregunta
Pulmonary vascular resistance is
Respuesta
-
is equal to that offered by the systemic circuit
-
decreased when alveolar oxygen pressure fails
-
expressed in units of volume flow per unit time per unit pressure gradients
-
decreased during exercise
-
regulated reflexvely by sympathetic vasoconstrictor nerves
Pregunta 97
Pregunta
Veins:
Respuesta
-
contain most of the blood volume
-
have a histaminergic vasodilator innervation
-
receive nutrition from vas vasorum arising from their lumen
-
respond to distension by dilation of their smooth muscle
-
do not contain valves
Pregunta 98
Pregunta
In the heart:
Respuesta
-
the left atrial wall is about three times thicker than the right atrial wall
-
systolic contraction normally begins in the left atrium
-
excitation spreads directly from atrial muscle cells to ventricular muscle cells
-
atrial and ventricular muscle contracts simultaneously in systole
-
the contracting ventricles shorten from apex to base
Pregunta 99
Pregunta
When measuring blood pressure by the auscultatory method:
Respuesta
-
the sounds that are heard are generated in the heart
-
the cuff pressure at which the first sounds are heard indicate systolic pressure
-
the cuff pressure at which the loudest sounds are heard indicate diastolic pressure
-
systolic pressure estimations tend to be lower than those made by the palpatory method
-
wider cuff's are required for smaller arms
Pregunta 100
Pregunta
The absolute refractory period in the ventricles:
Respuesta
-
is the period when the ventricles are completely still excitable
-
corresponds to the period of ventricular depolarization
-
corresponds approximately to the period of ventricular relaxation
-
is shorter than the corresponding period in atrial muscle
-
decreases during parasympathetic stimulation of the heart
Pregunta 101
Pregunta
Vascular resistance:
Respuesta
-
increases by 50 per cent When the vascular radius is halved
-
is related to the thickness of the wall of the vessel
-
is related to the vessel’s length
-
is affected by blood Hb concentration
-
is greater in the capillary bed than in the arteriolar bed
Pregunta 102
Pregunta
Sympathetic drive to the heart is increased:
Respuesta
-
in exercise
-
in relaxed position
-
in normotension
-
when parasympathetic drive is decreased
-
during a vasovagal attack
Pregunta 103
Pregunta
Hyperaemia in skeletal muscle during exercise is normally associated with:
Respuesta
-
release of sympathetic vasoconstrictor tone in the exercising muscles
-
capillary dilation due to relaxation of capillary smooth muscle
-
a fall in arterial pressure
-
reflex vasoconstriction in other vascular beds
-
an increase in venous pressure
Pregunta 104
Pregunta
Sinuatrial node cells are:
Respuesta
-
found in both atria
-
innervated by the somatic nerves
-
unable to generate impulses when completely denervated
-
connected to the AV node by fine bundles of purkinje tissue
-
able to generate impulses because their membrane potential is unstable
Pregunta 105
Pregunta
The first heart sound corresponds in time with:
Respuesta
-
closure of the aortic and pulmonary valves
-
the P wave of the electrocardiogram
-
a decline in atrial pressure
-
a rise in ventricular pressure
-
the A wave in central venous pressure
Pregunta 106
Pregunta
The velocity of blood flow:
Respuesta
-
in capillaries is low because they offer high resistance to flow
-
in veins is greater than in venules
-
can fall to zero in the ascending aorta during systole
-
is lower towards the centre of large blood vessels than at the periphery
-
in the circulation falls as the haematocrit falls
Pregunta 107
Pregunta
The strength of contraction of left ventricular muscle increases when:
Respuesta
-
end-diastolic ventricular filling pressure
-
serum potassium levels rise
-
blood calcium levels fall
-
blood magnesium levels fall
-
peripheral resistance is decreased
Pregunta 108
Pregunta
During isometric ventricular contraction:
Respuesta
-
the entry and exit valves of the ventricle are closed
-
pressure in the aorta rises
-
pressure in the atria falls
-
left coronary blood flow is going up
-
the rate of rise in pressure is greater in the right than in the left ventricle
Pregunta 109
Pregunta
Cardiac output:
Respuesta
-
is normally expressed as the output of one ventricle in liters/minute
-
is about 2.0 l at rest
-
is about 10.0 l at rest
-
rises in a cold environment
-
does not increase in exercise following denervatlon of the heart
Pregunta 110
Pregunta
In the brachial artery:
Respuesta
-
Pulse waves travel at the same velocity as blood
-
Pulse pressure falls with decreasing elasticity of the wall
-
Pressure rises markedly when the artery is occluded distally
-
Pressure falls when the arm is raised above head level
-
Pulse pressures have a smaller amplitude than aortic pulse pressures
Pregunta 111
Pregunta
Arterioles offer more resistance to flow than other vessels since they have:
Respuesta
-
thicker muscular walls
-
richer sympathetic innervation
-
smaller internal diameters
-
a smaller total cross-sectional area
-
a greater pressure drop along their length
Pregunta 112
Pregunta
In the denervated heart, left ventricular stroke work increases when:
Respuesta
-
the end-diastolic length of the ventricular fibres increase
-
peripheral resistance decreases
-
blood volume falls
-
right ventricular output decreases
-
the veins dilate
Pregunta 113
Pregunta
With increasing distance from the heart, arterial:
Respuesta
-
walls contain relatively more smooth muscle than elastic tissue
-
flow has a greater tendency to be turbulent
-
mean pressure tends to decrease slightly
-
pulse pressure tends to increase slightly
-
pO2 falls appreciably
Pregunta 114
Pregunta
In the estimation of cardiac output using the Fick principle:
Respuesta
-
pulmonary blood flow is measured
-
the pO2 of arterial and mixed venous blood are measured
-
oxygen uptake is estimated from alveolar pO2 measurements
-
pulmonary arterial blood is sampled to measure the oxygen in venous blood
-
pulmonary venous blood is sampled to measure the oxygen in arterial blood
Pregunta 115
Pregunta
Systemic hypertension may be caused by:
Respuesta
-
hypoxia due to chronic respiratory failure
-
excessive secretion of aldosterone
-
excessive secretion of insulin
-
myocardial thickening (hypertrophy) of the left ventricle
-
the rapid cardiac action of ventricular fibrillation
Pregunta 116
Pregunta
Peripheral differs from central circulatory failure in that:
Respuesta
-
hypovolaemia is unusual
-
it leads to underperfusion of the tissues
-
cardiac output is usually normal
-
central venous pressure is high
-
ventricular function is usually normal
Pregunta 117
Pregunta
In atrial fibrillation:
Respuesta
-
the electrocardlagram shows no evidence of atrial activity
-
ventricular rate is lower than atrial rate
-
respiratory sinus arrhythmia can usually be seen
-
the ventricular rate is higher than atrial rate
-
the QRS complexes have an abnormal configuration
Pregunta 118
Pregunta
Pain due to poor coronary blood flow (angina) may be relieved by:
Respuesta
-
Cutting the parasympathetic nerve trunks supplying the heart
-
Infecting CaCl2
-
Providing the patient with a cold environment
-
β-adrenoceptor stimulating drugs
-
Drugs causing peripheral vasodilation
Pregunta 119
Pregunta
Aortic valve incompetence may cause:
Respuesta
-
increase in arterial pulse pressure
-
systolic murmurs in the aortic valve area
-
hypertrophy of right ventricular muscle
-
decreased myocardial blood flow
-
right ventricular failure
Pregunta 120
Pregunta
Ventricular extrasystoles:
Respuesta
-
are usually associated with a normal QRS complex
-
from the same focus have similar QRS complexes
-
usually occur following a compensatory pause
-
can‘t be detected by ECG
-
indicate serious heart disease
Pregunta 121
Pregunta
Pulmonary embolism (blood clots impacting in lung blood vessels) usually decreases:
Respuesta
-
pulmonary vascular resistance
-
left atrial pressure
-
right atrial pressure
-
ventilation to perfusion ratios in the affected lung
-
pO2 in pulmonary venous blood
Pregunta 122
Pregunta
Hardening of the arterial walls tends to raise:
Respuesta
-
Arterial compliance
-
Systolic arterial pressure
-
Diastolic arterial pressure
-
Peripheral resistance
-
The frequency of breathing
Pregunta 123
Pregunta
Left ventricular failure tends to cause an increase in:
Respuesta
-
right atrial pressure
-
Ieft ventricular ejection fraction
-
pulmonary capillary pressure
-
lung compliance
-
pulmonary oedema when the patient stands up
Pregunta 124
Pregunta
In otherwise healthy people, local tissue death follows obstruction of:
Respuesta
-
an internal carotid artery
-
a renal artery
-
a femoral artery
-
a brachial artery
-
the hepatic portal vein
Pregunta 125
Pregunta
The part of the circulation pumping blood to and from the lungs is known as the _____ circulation.
Respuesta
-
systemic
-
pulmonary
-
coronary
-
respiratory
-
hepatic
Pregunta 126
Pregunta
The plateau phase of the action potential in contractile myocardiocytes is due to:
Respuesta
-
the slow movement of Na+ across the cell membrane
-
the influx of Ca2+
-
the increased membrane permeability to K+
-
the increased membrane permeability to Na+
-
a decrease in Ca2+ diffusing across membrane
Pregunta 127
Pregunta
The valve between the right ventricle and the vessel that leaves it is the _____ valve.
Respuesta
-
tricuspid AV
-
bicuspid AV
-
mitral
-
pulmonary semilunar
-
aortic semilunar
Pregunta 128
Pregunta
If the connections between the parasympathetic division of the ANS and the heart were cut, then
Respuesta
-
heart rate would decrease
-
stroke volume would decrease
-
cardiac output would decrease
-
heart rate would increase
-
heart activity would remain unchanged
Pregunta 129
Pregunta
Fenestrated capillaries:
Respuesta
-
have pores in their walls
-
are located in most tissue
-
permit only one-way exchange of materials
-
have a layer of smooth muscle in their walls
-
are found in the liver and kidneys
Pregunta 130
Pregunta
Absolute refractory period in the heart:
Respuesta
-
corresponds to the duration of relaxation
-
lasts till half of cardiac contraction
-
shorter than refractory period in skeletal muscle
-
lasts till cardiac contraction
-
last only 10 ms
Pregunta 131
Pregunta
First heart sound occurs during the period of:
Respuesta
-
isometric relaxation
-
isotonic relaxation
-
isovolumetric contraction
-
isovolumetric relaxation
Pregunta 132
Pregunta
Which of these vessels does not have sympathetic control:
Respuesta
-
cerebral
-
splanchnic
-
cardiac
-
cutaneous
-
muscle
Pregunta 133
Pregunta
Blood brain barrier is made up of:
Respuesta
-
astrocytes
-
oligodendrocytes
-
oligodendroglia
-
microglia
-
others
Pregunta 134
Pregunta
Positive bathmotropic effect on heart is produced by:
Respuesta
-
stimulation of vagus nerve
-
stimulation of sympathetic nerves
-
atropin
-
sectioning of vagus
-
K+
Pregunta 135
Pregunta
Which of the following conducting systems has the slowest conducting velocity:
Respuesta
-
SA node
-
Atrial muscle
-
Purkinje fibres
-
AV node
-
Hiss bundle
Pregunta 136
Pregunta
In heart, within physiological limits the force of contraction is directly proportional to the:
Respuesta
-
Pacemaker activity
-
AV nodal delay
-
Initial length of the cardiac muscle
-
Respiratory rate
-
ST-segment
Pregunta 137
Pregunta
The diacrotic notch on aortic pressure curve is caused by:
Respuesta
-
closure of mitral valve
-
closure of tricuspid valve
-
closure of atrial valve
-
closure of pulmonary valve
-
opening the atrial valve
Pregunta 138
Pregunta
The PR interval of ECG corresponds to:
Respuesta
-
ventricular repolarization
-
atrial repolarization and conduction through AV node
-
repolarization of AV node and bundle of His
-
depolarization of SA node
Pregunta 139
Pregunta
Increased vagal tone causes:
Respuesta
-
hypertension
-
tachycardia
-
bradycardia
-
increase in cardiac output
-
increase in stroke volume
Pregunta 140
Pregunta
Which of the following is not increased during exercise;
Respuesta
-
stroke volume
-
total peripheral resistance
-
systolic BP
-
heart rate
-
muscle blood flow
Pregunta 141
Pregunta
Which of the following takes longest time to return to normal after 1L of blood is removed from a normal individual:
Respuesta
-
number of RBC in peripheral blood
-
plasma volume
-
renin secretion
-
blood pressure
-
number of WBC in peripheral blood
Pregunta 142
Pregunta
In a patient with mitral stenosis one would expect to hear:
Respuesta
-
continuous murmur
-
a systolic murmur loudest over the base of heart
-
a diastolic murmur loudest over the apex of heart
-
a diastolic murmur loudest over the base of heart
-
systolic murmur over the apex of heart
Pregunta 143
Pregunta
The ‘S' wave in ECG is below isoelectric line because of:
Respuesta
-
repolarization of ventricles
-
change in direction of the impulse when the base of the ventricles are getting depolarised
-
depolarisation of apex of heart
-
repolarisation of apex of heart
-
depolarisation of atria
Pregunta 144
Pregunta
Lymph flow from the foot is:
Respuesta
-
increased when an individual rises from the supine to standing position
-
increased by massaging the foot
-
increased when capillary permeability is decreased
-
decreased by exercise
-
decreased by massaging the foot
Pregunta 145
Pregunta
The "T" wave in ECG is above the isoelectric line because of:
Respuesta
-
depolarisation of ventricles
-
depolarisation of bundle of His
-
change in the direction of repolarisation from the wave of depolarization of the ventricles
-
repolarisation of purkinje fibres
-
depolarisation of atria
Pregunta 146
Pregunta
Restoration of the blood volume after haemorrhage is aided by:
Respuesta
-
contraction of venous reservoirs
-
a fall in capillary pressure in certain vascular beds
-
arteriolar vasodilation
-
mobilization of intracellular fluid into the circulation
-
in increase in the osmotic pressure of the plasma proteins
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