Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medicine 1 (Year 1) > Cardiovascular > Flashcards

Cardiovascular Flashcards

1
Q

The superior and inferior vena cava drains blood into (chamber of the heart)

A

A. RIGHT ATRIUM The superior and inferior vena cava drains blood into (chamber of the heart) Right atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The (systemic/pulmonary) _____ circulation face greater resistance.

A

A. SYSTEMIC The SYSTEMIC circulation face greater resistance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The ____ collects blood from coronary vessels returning from the myocardium

A

A. CORONARY SINUS The CORONARY SINUS collects blood from coronary vessels returning from the myocardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The ____ is the muscular middle layer of the heart and forms the bulk of the heart tissue

A

A. MYOCARDIUM The MYOCARDIUM is the muscular middle layer of the heart and forms the bulk of the heart tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The ___ are tendons that attach to the atrioventricular valves and prevent regurgitation of blood back into the atrium

A

A. CHORDAE TENDINAE The CHORDAE TENDINAE are tendons that attach to the atrioventricular valves and prevent regurgitation of blood back into the atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The four ____ carry oxygenated blood from the lungs to the left atrium

A

A. PULMONARY VEINS The four PULMONARY VEINS carry oxygenated blood from the lungs to the left atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The _____ is the innermost layer of the heart and is made of a thin layer of endothelium

A

A. ENOCARDIUM The ENDOCARDIUM is the innermost layer of the heart and is made of a thin layer of endothelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The mitral valve has (two/three)___ leaflets

A

A. TWO The mitral valve has TWO leaflets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The _____ carry deoxygenated blood from the heart to the lungs

A

A. PULMONARY ARTERIES The PULMONARY ARTERIES carry deoxygenated blood from the heart to the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The _____ layer of the pericardium sticks to the heart itself forming the epicardium

A

A. VISCERAL The VISCERAL layer of the pericardium sticks to the heart itself forming the epicardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The heart sound typically heard in pulmonic stenosis is a (diastolic/systolic) ____ ejection murmur

A

A. SYSTOLIC The heart sound typically heard in pulmonic stenosis is a (diastolic/systolic) SYSTOLIC ejection murmur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The most common symptom of infective endocarditis is ____ which is very nonspecific

A

A. FEVER The most common symptom of infective endocarditis is FEVER which is very nonspecific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Milroy disease causes (primary/secondary) ____ lymphedema.

A

A. PRIMARY Milroy disease causes PRIMARY lymphedema.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The mainstay of management of tricuspid insufficiency is _____

A

A. treatment of the underlying cause. The mainstay of management of tricuspid insufficiency is TREATMENT OF THE UNDERLYING CAUSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A membrane potential of -85 millivolts means that the (interior/exterior) ____ of the cell is negative.

A

A. INTERIOR A membrane potential of -85 millivolts means that the (interior) of the cell is negative.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A(n) (early/late) ____ complication of rheumatic fever is mitral valve regurgitation.

A

A. EARLY A(n) (early/late) ____ complication of eheumatic fever is mitral valve regurgitation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The greater the amount of elastic tissue within a blood vessel, the (Higher/Lower) ___ the elastance

A

A.HIGHER The greater the amount of elastic tissue within a blood vessel, the (Higher/Lower) ___ the elastance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Conduction Velocity in the heart is slowest at the _____ node

A

A. ATRIOVENTRICULAR Conduction Velocity in the heart is slowest at the ATRIOVENTRICULAR node.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

____ due to decreased blood supply in the myocardium is characterized by inverted T waves on the electrocardiogram.

A

A. ISCHEMIA ___ due to decreased blood supply in the myocardium is characterized by inverted T waves on the electrocardiogram.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

An ECG usually ST segment (Elevation/Depression) _____ in a transmural myocardial infarction.

A

A. ELEVATION An ECG usually ST segment (Elevation/Depression) _____ in a transmural myocardial infarction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The anterior inferior cerebellar artery is a branch of the ____ artery

A

A. BASILAR The anterior inferior cerebellar artery is a branch of the ____ artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

____ describes the formation of sterile skin pustules after minor trauma and is characteristically found in Behcet disease.

A

A. PATHERGY describes the formation of sterile skin pustules after minor trauma and is characteristically found in Behcet disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

____ is the most important risk factor for stroke

A

A. HYPERTENSION ____ is the most important risk factor for stroke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

a holosystolic (pansystolic) murmur at the lower left sternal border is most likely caused by ___ or tricuspid regurgitation.

A

A. ventricular septal defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Thrombophlebitis secondary to peritonitis most commonly occurs in the ____

A

A. portal vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

____ is the most common risk factor for atrial fibrillation.

A

A. hypertension. is the most common risk factor for atrial fibrillation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Severe pericardial effusion can lead to the clinical triad of _______ _________ and _____

A

A. hypotension, distended neck veins, and muffled heart sounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Renal disease in adults having Henoch-Schonlein purpura is (more/less) severe than that of the children affected by the same disease

A

A. more severe.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

The best initial test to diagnose atherosclerosis of the vessels of the lower limb is the_____

A

A. ankle-brachial index.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

A consequence of increased (preload/afterload) ___ is that less blood is ejected from the ventricle during systole

A

A. Afterload

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Hypoplastic left heart syndrome is the most common cause of death from cardiac defects in the (time period) ___ of life

A

A. First month.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

(endovascular/open surgical) ____ procedures for treating subclavian steal syndrome have fewer complications.

A

A. endovascular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is not content of mediastinum: heart, lung thoracic duct oesophagus. primary bronchi

A

lung

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what is lateral relationship of the heart? a phrenic nerve b pleura c pleura and phrenic nerve d. vagus nerve e. pleura and vagus nerve

A

Pleura and phrenic nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

heart lies anterior to which vertebrae a. t1-t4 bt2-t5 ct4-t7 et5-t8

A

t5 - t8 vertabrae recomband (laying down) t5-t8 4 thoracit vertabrae. when standing lung drops slightly. lays behind costal cartilage 4-7 but vertabrae t5 - t8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Anterior suface of heart is formed by a. rv b ra +rv c ra - rv -lv d ra rv la lv e rv la lv

A

Ra + rv and LV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the location of apex of heart a) 5th l intercostal space midaxillary line b) 5th intercostal space parasternal line c) 5th intercostal space midclavicular line d) 4th left intercostal space midclavicular line e) 4th left intercostal space midaxillary line

A

5th intercostal space, midclavicular line. REMEMBER LEFT.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

phrenic nerve supplies a- visceral pericardium b- parietial pericardium fibrous pericardiam fibroud paratiel pericardium partietal and visceral pericardium

A

fibrous and patietal pericardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

which correct sympathetic innervation a decrease hr b increase rt and force contraction c root value t1 - t6 d innervate parietal layer of the pericardium e relax the heart muscle

A

increases heart rate and force of contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

which following correct a) coronary sulcus grow between the right atrium and right ventricle b) circumflex artery branch of right coronary artery c) anterior descending artery is a branch of left coronary artery d) coronary artery arise from coronary sinuses e) posterior descending artery is a branch of the left coronary artery

A

A. C a- no right and left atrium and ventricle B- no circumflex is branch left coronary artery c) CORRECT d) Not coronary sinuses artery arise, aortic sinuses rise. e) branch of the RIGHT coronary artery.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

anterior descending artery supplied which areas of heart ventricle a) ra + rv b rv + lv c) rv +lv + la d) rv + lv + IVS

A

d) rv + lv + IVS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

coronary sinus drains into a) left atrium b) right atrium c) azygos vein d) superior vena cava e) interatrial septa

A

b) Right atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Vacsulogenesis _______ Angiogenesis _________

A

Vasculogenesis: The NEW formation of a primitive vascular network Angiogenesis: The growth of new vessels from PRE-EXISTING blood vessels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Which electrolyte maintains the resting potential of ventricular myocytes?

A

Potassium maintains the resting potential of cardiac myocytes, with depolarization triggered by a rapid influx of sodium ions, and repolarization due to the efflux of potassium. A slow influx of calcium is responsible for the longer duration of a cardiac action potential compared with skeletal muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Hearing a noise after the lub and before the dub can be what?

A

it is a systolic mumur - can be caused by stenosis of aortic /pulmonary valve or regurgitation through mitral/tricuspid valces

46
Q

what is the “lub” noise?

A

mitral and tricuspid valve closing

(aortic/pulmonary valves are open)

47
Q

what is the “dub” noise?

A

the aortic and pulmonary valves closing (mitral and tricuspid valves closing)

48
Q

if you have a murmur after dub (diastole) what is this?

A

diastolic murmur - could be due to stenosis of mitral/tricuspid valves or regurgitation through aortic/pulmonary valves.

49
Q

what could cause a continuous murmur?

A

hole in the septum

left side heart building up to higher pressure than right. pressure L side higher throughout whole cardiac cycle than R. sp hole heart (septal defect) cause a continuous murmur

50
Q

Regulation of heart rate sympathetic

A
  • nerves release noradrenaline

circulating adrenaline from the adrenal medulla

both act on b1-receptors on sinoatrial node

increases slope of pacemaker potential

increases heart rate = tachycardia.

51
Q

regulation of heart rate parasympathetic

A

rest and digest vagus nerve (craniosacral outflow) releases acetylcholine from head to heart

acting on muscarinic cells on the sinoatrial node - hyper polarises decreases slope of pacemaker potential

threshold later interval

decreases HR bradycardia.

52
Q

regulate stroke volume - preload

A

preload starling law - energy contraction proportional to the initial length of cardiac muscle fibre.

53
Q

in vivo what is preload affected by

A

end-diastolic volume

end-diastolic volume - amount blood left in left ventricle before contraction

Preload or left ventricular end-diastolic pressure (LVEDP),- the initial stretching of the cardiac myocytes prior to contraction/the amount of ventricular stretch at the end of diastole

* so amount of LV stretch before contraction is affected by how much blood is in the LV*

54
Q

for stroke volume and preload what does an increase in end-diastolic volume cause?

A

larger the end diastolic volume, the bigger stretch on the cardiac muscle and therefore larger stroke volume.

stroke volume = volume of blood pumped from the left ventricle per beat.

end-diastolic volume - amount blood left in left ventricle before contraction.
Preload or left ventricular end-diastolic pressure (LVEDP),- the initial stretching of the cardiac myocytes prior to contraction/the amount of ventricular stretch at the end of diastole

55
Q

what is increased venous return

A

increased end-diastolic volume (vol blood in lv after diastole) and therefore

increased stroke volume (volume blood pumped from the LV per beat)

56
Q

Decreased venous return =

A

reduces end-diastolic volume (volume in lv after diastole) therefore

decreased stroke volume - (volume blood pumped from the LV per beat)

57
Q

what’s the purpose of increased/decreased venous return

A

to ensure self-regulation. make sure both ventricles pump roughly the same amount of blood

58
Q

afterload =

A

Afterload is the pressure that the heart must work against to eject blood during systole. Afterload is proportional to the average arterial pressure

59
Q

if cardiac muscle is trying to shorten what does it try to do?

A

push the mitral valve shut

what is stopping it from getting shorter is aortic valve being shut.

60
Q

what is aortic pressure?

what will it be affected by?

A

the aortic valve shutting

it will be affected by how easy it is for blood to get out the arterioles = the total peripheral resistance (TPR)

61
Q

stroke volume with the sympathetic nervous system

A

bigger stroke volume

sympathetic nerves releasing noradrenaline + circulating adrenaline and adrenal medulla.
both act on b1- receptors on the myocytes.

increases contractility (inotropic effect)

gives stronger but shorter contraction

*more excitation-contraction coupling, more Ca+ more cross-bridges stronger contraction but shorter at Ca+ taken up quicker =more time diastole*
bigger stroke volume

62
Q

stroke volume with parasympathetic effect

A

little effect - because the vagus does not innervate the ventricular muscle.

innervates top of heart, atria and sinoatrial node.

63
Q

if you get increase HR in exercise what happens to cardiac output?

A

CARDIAC OUTPUT INCREASES :

HR increases - via decreased vagal tone (vagus nerve releasing acetylcholine) increased sympathetic tone

contractility increases - increased sympathetic tone alters inotropic state and shortens systole (act b1 receptors)

venous return increases - via vasoconstriction +skeletal/respiratory pumps maintains preload *constriction returns more blood to heart = increase end-diastolic volume*

total peripheral resistance falls. - due to arteriolar dilation in muscle, skin and heart reduces afterload. (dilate arterioles)

64
Q

pressure waves are affected by

A

stroke volume

velocity of ejection

elasticity of arteries

total peripheral resistance

65
Q

normal blood pressure

A

120/80

but can range with age etc

66
Q

pressure flor through arteries and veins

through vasular tree

A

small drop 95mmHg to 90mmHg as low resistance condiut

67
Q

pressure flor through arteries and veins

arterioles

A

large drop 90mmHg-40mmHg as resistance vessels

68
Q

pressure flor through arteries and veins capillaries

A

already low and this is good because they are thin-walled (1 cell thick)

69
Q

pressure flor through arteries and veins leaving back through veins

A

leaves small pressure difference from 20mmHg to 5mmHg

70
Q

pressure flor through arteries and veins pulmonary circulation pressure

A

1.5 of systemic

71
Q

velocity when relating to cross section

A

fastest in aorta and vena cava

slowest in capillaries

72
Q

pressure and flow in veins

end diastolic volume when standing and laying

A

when standing a smaller end-diastolic volume - smaller preload - reduce stroke volume

co is less and MAP less.

cause distention of blood in legs

when laying - larger end-diastolic volume

73
Q

if you have a reduced mean arterial pressure

A

insufficient profusion to body

the brain notices most = faint.

postural hypotension.

74
Q

raised central venous pressure - neck

dropped venous pressure

A

The neck vein can collapse = below the clavicle.

venous pressure raises a lot - ven can be visible

75
Q

arterial baroreflex

A

sensors in aotric arche and some in carotid sinus

stretch receptors to sense stretch on wall increase fire rate to fire action potential

76
Q

what is normal MAP

what is ideal

A

70 and 100 mmHg normal

ideal - 90-95mmHg

77
Q

when receiving signal from aortic baroreceptor and caroited sinus baroreceptors what happens next

A

sensory or afferent fibres travel up to brain

aortic arch signal travels up vagus nerve (motor autonomic)

caroited sinus baroreceptor signal travel up in cranial nerve glossopharyngeal nerve.

both go to medullary cardiovascular centre

78
Q

when the signal travels up the vagus nerve and the glossopharyngeal nerve, where does this arrive?

centre?

A

both go to medullary cardiovascular centre

79
Q

the medullary cardiovascular centre can then respond by signals where?

parasympathetic

A

parasympathetic - down vagus nerve to innervate sinoatrial node (pacemaker of the heart)

-acetylcholine - muscarinic receptor, hyperpolarise pacemaker cell = slower

80
Q

the medullary cardiovascular centre can then respond by signals where?

sympathetic

A

down sympathetic nerves

sinoatrial node - noradrenaline - b1 receptors - depolarise faster = increase hr .

innervate muscle ventricle b1 - increase ca+ entering

cross-bridge constrict blood vessels adrenaline (alpha1)

venous ^ stroke vol etc

81
Q

cardiopulmonary baroreceptors

A

sense central blood volume (stretch receptors)

fire action potential relay medullary cardiovascular centre

82
Q

receptors sensing pco2 and po2

A

central chemoreceptors

increase breathing or decrease trigger bp or decrease

83
Q

receptors sensing metabolite concentration

A

chemoreceptor in muscle

84
Q

receptors sensing joint movement

A

joint receptors

85
Q

higher centres

A

hypothalamus and cerebral cortex

86
Q

what is the valsalva manoevre

A

forced expiration against a closed glottis

87
Q

what is the initial effect of the valsalva menoevre

A

stops venous return reduced preload on the heart and therefore reduces cardiac output

88
Q

why would you get someone to perform the Valsalva manoeuvre?

A

to assess the strength of someone’s baroreflex

89
Q

Concerning the vascular system: Most vascular beds are arranged in parallel.

Select one:

True

False

A

True. The significance of this being that all body regions receive fresh oxygenated blood, and that the cardiac output can be redirected between different body regions when require

90
Q

Concerning the vascular system: Most arterioles are innervated only by parasympathetic nerves.

Select one:

True

False

A

False. Most blood vessels are innervated only by sympathetic vessels. These release noradrenaline which activates alpha 1 receptors and causes vasoconstriction. Most vessels are not innervated by the parasympathetic system. The genitalia and salivary glands are the exceptions that prove the rule.

91
Q

Concerning the cardiovascular system: The circular smooth muscle of arterioles controls peripheral resistance under the influence of the sympathetic nervous systems

Select one:

True

False

A

True. The arterioles are indeed the resistance vessels. The smooth muscle surrounding them is controlled by intrinsic mechanisms, but also by central mechanisms. Notably the sympathetic nerves which innervate the arterioles and release noradrenaline, and adrenaline which is released from the adrenal medulla. Both of these activate alpha 1 receptors on the smooth muscle which causes arteriolar constriction and regulates peripheral resistance.

92
Q

Concerning the cardiac cycle: At resting heart rate, systole takes approximately twice as long as diastole.

Select one:

True

False

A

False. At resting heart rate, systole takes about 1/3rd of the cardiac cycle, ie it is half as long as diastole. At higher heart rates, most of the time is taken out of diastole and so systole takes a proportionally greater proportion of the cycle.

93
Q

Concerning the cardiac cycle: The stroke volume of the right ventricle is approximately one fifth of that of the left ventricle.

Select one:

True

False

A

False. The right and left sides of the heart lie in series and must have the same cardiac output or blood will accumulate in the systemic or pulmonary circulations. They have the same heart rate because they share the same pacemaker, so the stroke volume must also be the same. If you got it wrong you were probably thinking of the pressure evoked by the left ventricle, which is about one fifth of that of the left.

94
Q

Concerning the electrical activity of the heart: Cells of the myocardium are electrically connected via gap junctions.

Select one:

True

False

A

True. Cells of the myocardium are both electrically connected (via gap junctions) and physically connected (via the desmosomes). Hence it acts as functional syncytium which depolarizes as one, and contracts as one.

95
Q

Concerning the cardiac cycle: The left atrial pressure rises at the start of systole.

Select one:

True

False

A

True. When the ventricle contacts, the mitral and tricuspid valves close and then bulge into the atria, creating the a wave on the atrial pressure trace, which terminates when the aortic and pulmonary valves open.

96
Q

Concerning the arterial baroreflex: A fall in baroreceptor firing rate triggers a reflex increase in sympathetic outflow.

Select one:

True

False

A

True. A fall in baroreceptor firing rate signals a fall in mean arterial pressure which triggers (amongst other things) an increase in sympathetic outflow. This will increase heart rate, increase stroke volume, cause venoconstriction and cause arteriolar constriction, all of which will contribute a pressor response - ie an increase in blood pressure.

97
Q

Concerning the cardiac cycle: A systolic murmur could be caused by regurgitation of blood through the aortic valve.

Select one:

True

False

A

False. A murmur is generally caused by turbulence in the blood due to regurgitation through a valve that should be closed, or stenosis (narrowing) of a valve that should be open. During systole the aortic valve is open so a systolic murmur could be due to stenosis of the aortic valve. Regurgitation through the aortic valve would cause a diastolic murmur.

98
Q
A
99
Q

Regarding control of the peripheral circulation: Increasing the radius of an arteriole 2-fold, increases its resistance 16-fold.

Select one:

True

False

A

False. Close. Varying radius does alter resistance to the power of 4, but increasing radius will reduce resistance, not increase it.

100
Q

Regarding control of the peripheral circulation: The injury response depends on intact nociceptive nerve function.

Select one:

True

False

A

True. The injury response depends on action potentials invading the terminals of nociceptive C-fibres and triggering the release of substance P.

101
Q

Concerning the vascular system: Rhythmic contraction of skeletal muscle promotes venous return.

Select one:

True

False

A

True. This the action of the skeletal muscle pump. It is one of several mechanism that increase venous pressure and venous return during exercise and therefore offset the reduction in end diastolic volume caused by heart heart rates. The others include the respiratory pump, venomotor tone, and increased systemic filling pressure.

102
Q

Regarding control of the peripheral circulation: Circulating adrenaline causes arteriolar constriction in all body regions.

Select one:

True

False

A

False. Whilst adrenaline activates alpha 1 receptors and causes arteriolar constriction in the vast majority of body regions, there are notable exceptions. These are the skeletal muscle and cardiac muscle which also express beta 2 receptors which cause arteriolar dilation and swamp the alpha 1 receptor mediated constriction.

103
Q

Concerning the arterial baroreflex: Sensory information from the arterial baroreceptors is primarily concerned with regulation of mean arterial pressure in the short, rather than the long, term.

Select one:

True

False

A

True. Cutting the sensory nerves from the aortic and arch and carotid sinus baroreceptors results in loss of short-term, but not long-term, control of blood pressure. Long term control of blood pressure may rely more on sensory input from the cardiopulmonary baroreceptors.

104
Q

Concerning the arterial baroreflex: Rising from a sitting to a standing position will cause a reflex increase in heart rate and total peripheral resistance.

Select one:

True

False

A

True. But do you understand the mechanism? Standing causes pooling of blood in the venules of the feet and legs. This reduces end diastolic volume and therefore preload, stroke volume, cardiac output and mean arterial pressure. This fall in blood pressure is sensed by the arterial baroreceptors which trigger a reflex increase in, amongst other things, heart rate and total peripheral resistance to restore blood pressure.

105
Q

Concerning the pumping ability of the heart: Stimulation of sympathetic fibres innervating the heart increases contractility.

Select one:

True

False

A

True. Noradrenaline acting on beta1 receptors increases excitation-contraction coupling and gives a stronger contraction for any given preload.

106
Q

Concerning the cardiac cycle: The second heart sound is heard at the start of diastole.

Select one:

True

False

A

True. The first heart sounds is caused by the mitral and tricuscpid valves closing at the start of systole, and the second is caused by the aortic and pulmonary valves closing at the start of diastole

107
Q

Regarding control of the peripheral circulation: Metabolic autoregulation is a mechanism which matches the metabolic rate of a body region to its energy reserves.

Select one:

True

False

A

False. Metabolic autoregulation is a mechanism that matches the blood flow of a body region to its metabolic demands.

108
Q

Concerning the pumping ability of the heart: Cutting the sympathetic and parasympathetic innervation of the sinoatrial node will cause an increase in resting heart rate.

Select one:

True

False

A

True. The fastest (and therefore the) pacemaker cells of the heart have an inherent rate of about 100 beats per minute. This can be speeded up by the sympathetic system or slowed down by the parasympathetic system. At rest, the parasympathetic system dominates and so the heart is said to be under vagal restraint, giving the resting heart rate of about 70 beats per minute.

109
Q

Concerning the electrical activity of the heart: The Q-T interval gives a rough indication of the duration of ventricular systole.

Select one:

True

False

A

True. The Q-T interval indicates the time between ventricular depolarisation and ventricular repolarisation, ie the length of the ventricular action potential. This is approximately the same as the length of the contraction evoked and therefore the duration of systole.

110
Q

What determines preload

A

The end diastolic volume - the volume of blood in the heart at the end of diastole
Venous return and filling time

111
Q
A

Medicine 1 (Year 1) (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions