Chapter 18 The Cardiovascular System Part 2

Front 1

#1
The heart muscle is stimualted by ________ and is ________.

Back 1

nerves
self-excitable (automaticity)
or autorhythmic
(nerves slow the heart down or speed it up; they influence the rate of contraction.

Front 2

#2
The heart contracts as a unit because of ___ ____.

Back 2

gap junctions

Front 3

#3
Cariac muscle contraction is similar to ____ _____ contraction.

Back 3

skeletal muscle

Front 4

#4
Why does the heart continue to beat even after nerve connections are severed?

Back 4

because of gap junctions and intrinsic conduction system.

Front 5

#5
What cells initiat action potentials (contractions) and have an unstable resting potential called pacemaker potentials (prepotentials)?

Back 5

Autorhythmic cells

Front 6

#6
What cells continuously drifts toward threshold and membrane that is leaky to Na+, but less permeable to K+. Also uses calcium influx (rather than sodium) for rising phase of the action potential.

Back 6

Autorhythmic cells

Front 7

#7
What is the definition of polarization~

Back 7

When two sides of the membrane are different

Front 8

#8
Impulse passes from atria to ventricles via the ______ _____.

Back 8

Atrioventricular bundle
(bundle of His)

Front 9

#9
The AV blundle splits into two pathways in the _____ _____.

Back 9

interventricular septum
(bundle branches; right and left)

Front 10

#10
__ ___ carry the impulse toward the apex of the heart.

Back 10

Bundle branches

Front 11

#11
___ ___ carry the impulse to the heart apex and ventricular walls.

Back 11

Purkinje fibers

Front 12

#12
The SA node is the fastest due to ~

Back 12

more gap junction; the quicker the cell contracts

Front 13

#13
The first contraction is due to~

Back 13

the shortening of the papillary muscles

Front 14

#14
What is known as the "pacemaker" of the heart?

Back 14

SA (sinoatrial) node

Front 15

#15
This is the conduction of?
1. Sinoatrial (SA) node
2. Atrioventricular (AV) node
3. Atrioventricular (AV) bundle
4. Bundle branches
5. Purkinje fibers

Back 15

Cardiac Intrinsic Conduction
1. SA node has more gap junctions and is the fastest
2. & 3. Atria is contracting and relaxing
4. & 5. Ventricles contraction starts with shortening of papillary muscles.

Front 16

#16
Where is the SA node located?

Back 16

In the right atrial wall, infereior to the entrance of the superior vena cava

Front 17

#17
This intrinsic rate is the sinus rhythm - it determines the heart rate~

Back 17

SA node

Front 18

#18
Impulse follows the internodal pathway (gap junctions) to the ____ ____.

Back 18

Atrioventricular (AV) node

Front 19

#19
What is in the infereior portion of the interatrial septum, above the tricuspid valve and delays impulse slightly to allow atria to complete their contraction before ventricular events?

Back 19

Atrioventricular (AV) node

Front 20

#20
What is called the bundle of His?

Back 20

Atrioventricular bundle
(AV bundle)

Front 21

#21
What is the electrical connection between the atria and ventricles (only electrial connection)?

Back 21

AV bundle

Front 22

#22
This is insulated by the fibrous skeleton of the heart and is divided into right and left bundle branches?

Back 22

AV bundle

Front 23

#23
This course goes through the interventricular septum to apex of the heart

Back 23

AV bundle

Front 24

#24
What are the long strands to cardiac muscle cells with very few myofibrils (more elaborate on left side)?

Back 24

Purkinje fibers

Front 25

#25
These fibers excite the septal cells, they end at papillary muscles which contract slightly before the rest of the ventricle and tighten the chordae tendinae to stableize vale cusps prior to full contraction~

Back 25

Purkinje fibers

Front 26

#26
What do you call irregular heart rythms?

Back 26

Arrhythmias

Front 27

#27
What do you call rapid and irregular contractions / Control of heart rhythm is taken away for the SA note~

Back 27

Fibrillation

Front 28

#28
Fibrillating ventricles are _____ pumps.

Back 28

inefficient

Front 29

#29
Give two examples of a defective SA node.

Back 29

1. Ectopic focus may develop (a node somewhere it doesn't belong)
2. AV node may take over (AV node is slower - you will not get effective contraction of the atria.

Front 30

#30
A premature contraction is know as ____.

Back 30

Extrasystole

Front 31

#31
___ ___ carry the impulse to the heart apex and ventricular walls.

Back 31

Purkinje fibers

Front 32

#32
The SA node is the fastest due to ~

Back 32

more gap junction; the quicker the cell contracts

Front 33

#33
The first contraction is due to~

Back 33

the shortening of the papillary muscles

Front 34

#34
What is known as the "pacemaker" of the heart?

Back 34

SA (sinoatrial) node

Front 35

#35
This is the conduction of?
1. Sinoatrial (SA) node
2. Atrioventricular (AV) node
3. Atrioventricular (AV) bundle
4. Bundle branches
5. Purkinje fibers

Back 35

Cardiac Intrinsic Conduction
1. SA node has more gap junctions and is the fastest
2. & 3. Atria is contracting and relaxing
4. & 5. Ventricles contraction starts with shortening of papillary muscles.

Front 36

#36
Where is the SA node located?

Back 36

In the right atrial wall, infereior to the entrance of the superior vena cava

Front 37

#37
This intrinsic rate is the sinus rhythm - it determines the heart rate~

Back 37

SA node

Front 38

#38
Impulse follows the internodal pathway (gap junctions) to the ____ ____.

Back 38

Atrioventricular (AV) node

Front 39

#39
What is in the infereior portion of the interatrial septum, above the tricuspid valve and delays impulse slightly to allow atria to complete their contraction before ventricular events?

Back 39

Atrioventricular (AV) node

Front 40

#40
What is called the bundle of His?

Back 40

Atrioventricular bundle
(AV bundle)

Front 41

#41
What are the long strands to large cardiac muscle cells with very few myobibrils. They are more elaborate on left side).

Back 41

Pukinje fibers

Front 42

#42
The purkinje fiberts excite ____ cells.

Back 42

septal

Front 43

#43
Purkinje fibers end at ___ muscles which contract slighly before the rest of the ventricle.

Back 43

papillary muscles

Front 44

#44
The purkinje ribers righten the ___ ___ to stablize valve cusps prior to full contraction

Back 44

chordae tendinae

Front 45

#45
Irregular heart rhythms is known as ____.

Back 45

Arrhythmias

Front 46

#46
What is the word that describes rapid and irregular contractions, control of theart rhythm is taken away from the SA node?

Back 46

Fibrillation

Front 47

#47
Fibrillating ventricles are _____ pumps.

Back 47

inefficient

Front 48

#48
List two ways the fibrillating ventricles are inefficient.

Back 48

1. defibrillation is required immediately
2. deposlarizes the entire mycardium allowing intrinsic control to reboot.

Front 49

#49
List two things that may occur due to a defective SA node.

Back 49

1. Ectopic focus may develop ( a node somewhere it shouldn't be)
2. AV node may take over (AV node is slower - you will not get effective contraction of atria).

Front 50

#50
What is the name for premature contraction?

Back 50

Extrasystole

Front 51

#51
Extrasystole occasionally develops when a region of the heart becomes ___.

Back 51

hyperexcitable

Front 52

#52
Does extrasystole generate impusles that are faster or slower than the SA node?

Back 52

faster - (extra beat)

Front 53

#53
The heart is stimulated by the _____ cardioacceleratory center.

Back 53

Sympathetic
(kicks in when heart speeds up)

Front 54

#54
The heart is inhibited by the _____ cardioinhibitory center.

Back 54

Parasympathetic
(chilling out / slows down)

Front 55

#55
Electrical activity is recorded by an ________ - composite of all the AP's generated.

Back 55

electrocardiogram (ECG)

Front 56

#56
The P wave corresponds to ______ of the SA node

Back 56

depolarization

Front 57

#57
QRS complex correcsponds to _________ _________.

Back 57

ventricular depolarization

Front 58

#58
T wave corresponds to _______ ________.

Back 58

ventricular repolarization

Front 59

#59
Atrial repolarization record is masked by the larger ____ complex.

Back 59

QRS

Front 60

#60
Heart sounds lub-dup are associated with the ______ of the heart valves.

Back 60

closing

Front 61

#61
The first sound of the heart occurs as the __ ____ close and signifies the beginning of _______.

Back 61

AV valves
systole ( contraction of ventricle)

Front 62

#62
The second sound of the heart occurs when the ___ valves close at the beginning of _____ _______.

Back 62

SL
ventricular diastole (relaxation of ventricle)

Front 63

#63
What is the order of Electrocardiography?

Back 63

See picture

Front 64

#64
When does ventricular filling occur?

Back 64

Mid to late diastole (relaxation)

Front 65

#65
How does ventricular filling occur?

Back 65

1. Heart blood pressure is low as blood enters atria and flows into ventricles.
2. AV valves are open, semilunar valves are closed.
3. Most blood flows passively into ventricles, partially closing the AV valves.
4. Then atrial systole occurs (contraction)

Front 66

#66
What are the functions of Atrial systole (contraction)?

Back 66

1. Atria contract cuasing a rise in atrial blood pressure
2. Ventricles now contain the MAXIMUM amount of blood they will contain within the cardiac cycle
3. Ventricles are at the END of their DIASTOLIC PERIOD.
4. The volume of blood they now contain is the End Diastolic Volume (EDV)
5. Then atria relax (begin atrial diastole (relax) and the ventricles depolarize.

Front 67

#67
What are the three phases of the cardiac cycle?

Back 67

Ventricular systole
Isovolumetric contraction phase
Ventricular ejection

Front 68

#68
What tow things happen during ventricular systole?

Back 68

1. As the atria relax, the ventricles begin to contract
2. Rising ventricular pressure results in closing of the AV valves.

Front 69

#69
What is the isovolumetric contraction phase?

Back 69

The very short time when the ventricles are closed chambers
(AV valves and semilunar valves are both closed)

Front 70

#70
When phase opens the semilunar valves

Back 70

Ventricular ejection

Front 71

#71
What is Ventricular ejection?

Back 71

It's when ventricular pressure exceeds arterial pressure.

Front 72

#72
During the Ventricular ejection phase, the pressue in the aorta normally reaches about ____ mm Hg.

Back 72

120 mm Hg

Front 73

#73
When does isovolumetric relaxation happen?

Back 73

early diastole (relaxation)

Front 74

#74
What happens during Isovolumetric relaxation?

Back 74

1. ventricles relax
2. blacklow of blood in aorta and pulmonary trunk closes semilunar valves
3. Blood remaining in ventricles is the END SYSTOLIC VOLUME (ESV)

Front 75

#75
_________ is a brief rise in aortic pressure caused by backflow of blood rebounding off semilunar valves

Back 75

Dicrotic notch

Front 76

#76
During ventricular systole, the atria are ______ with blood and the intra-atrial pressure is ______

Back 76

refilling
rising

Front 77

#77
When the pressure within the atria exceeds that of the ventricles the ___ valves open and the cardiac cycle begins again.

Back 77

AV

Front 78

#78
Blood flow through the heart is controlled by _____ _____.

Back 78

pressure changes

Front 79

#79
Bllod flows down a ____ _____ through available openings.

Back 79

pressure gradient

Front 80

#80
_______ is the amount of blood pumped by each ventricle in one minute

Back 80

Cardiac output

Front 81

#81
Cardiac Output is the product of the _____ _____ and the ____ _____.

Back 81

heart rate
stroke volume

Front 82

#82
______ is the number of heart beats per minute.

Back 82

Heart rate

Front 83

#83
_____ is the amount of blood pumped out by a ventricle with each beat.

Back 83

Stroke volume

Front 84

#84
____ is the difference between resting and maiximal cardiac output.

Back 84

Cardiac Reserve

Front 85

#85
Cardiac Output Example:
CO (ml/min) = HR (75 beats/min X SV (70 ml/beat)

CO = 5250 ml/min (5.25 L/min)

Back 85

This is approximately the normal blood volume. Therefore, the entire blood supply is pumped through the heart each minute.

Front 86

#86
____ = end diastolic volume (EDV) minus end systolic volume (ESV)

Back 86

Stroke Volume (SV)

Front 87

#87
_____ = amounto f blood colelcted in a ventricle during diastole.

Back 87

End Diastolic Volume (EDV)

Front 88

#88
_____ = the amount of blood remaining in a ventricle after contraction

Back 88

End Systolic Volume (ESV)

Front 89

#89
______ - amount ventricles are stetched by contained blood.

Back 89

Preload

Front 90

#90
______ - cardiac cell contractile force due to factors other than end diastolic volume (EDV).

Back 90

Contractility
affects the ability of the heart to contract; effects the cells
(scarring, drugs can cause this)

Front 91

#91
______ - back pressure exerted by blood in the large arteries leaving the heart

Back 91

afterload

(extremely high blood pressure, not able to push out as much blood)

Front 92

#92
Preload, or degree of stretch of cardiac muscle cells before they contract is the critical factor controlling _____ _____.

Back 92

stroke volume

Front 93

#93
Slow heartbeat and exercise increase venous return to the heart increasing ____ ____.

Back 93

stroke volume

Front 94

#94
What two things decrease stroke volume?

Back 94

blood loss
extremely rapid heartbeat

Front 95

#95
The pressure that the ventricles must overcome to force blood into the arteries is _______.

Back 95

afterload

Front 96

#96
What is the pressure amount that the ventricles must overcome to force blood into the arteries?

Back 96

80 mm Hg

Front 97

#97
Why is afterload high in individuals with hypertension?

Back 97

Because it reduces the ability of ventricles to eject blood. Resulting in an increase End Systolic Volume and reduced Stroke Volume

Front 98

#98
______ is the increase in contractile strenth, independent of stretch and EDV

Back 98

Contractility

Front 99

#99
Contractility results in the increased ejection of blood from the heart, lower _____ and higher _____.

Back 99

ESV
SV

Front 100

#100
Increase in contractility comes from what three things?

Back 100

Increased sympathetic stimuli (norepinephrine & epinephrine)

Certain hormones

Ca2+ and some drugs

Front 101

#101
What extrinsic factors / agents decrease contracility?

Back 101

Acidosis
Increased extracellular K+
Calcium channel blockers

Front 102

#102
The sympathetic nervous system (SNS) stimulation is activated by what four things?

Back 102

stress
anxiety
excitement
exercise
(heart beats faster)

Front 103

#103
The parasympathetic nervous system (PNS) stimulation is mediated by ______ that opposes the SNS.

Back 103

acetylcholine
(slow heart beat)

Front 104

#104
The parasympathetic nervous sytem (PNS) dominates over the sympathetic nervous system (SNS) causing?

Back 104

the autonomic stimualation, slowing heart rate and causing vagal tone.
(PNS) dominates if you're healthy)

Front 105

#105
A sympathetic reflex initiated by increased blood in the atria is ______.

Back 105

Atrial (Bainbridge) Reflex

Front 106

#106
What is the pressure amount that the ventricles must overcome to force blood into the arteries?

Back 106

80 mm Hg

Front 107

#107
Why is afterload high in individuals with hypertension?

Back 107

Because it reduces the ability of ventricles to eject blood. Resulting in an increase End Systolic Volume and reduced Stroke Volume

Front 108

#108
______ is the increase in contractile strenth, independent of stretch and EDV

Back 108

Contractility

Front 109

#109
Contractility results in the increased ejection of blood from the heart, lower _____ and higher _____.

Back 109

ESV
SV

Front 110

#110
Increase in contractility comes from what three things?

Back 110

Increased sympathetic stimuli (norepinephrine & epinephrine)

Certain hormones

Ca2+ and some drugs

Front 111

#111
What extrinsic factors / agents decrease contracility?

Back 111

Acidosis
Increased extracellular K+
Calcium channel blockers

Front 112

#112
The sympathetic nervous system (SNS) stimulation is activated by what four things?

Back 112

stress
anxiety
excitement
exercise
(heart beats faster)

Front 113

#113
The parasympathetic nervous system (PNS) stimulation is mediated by ______ that opposes the SNS.

Back 113

acetylcholine
(slow heart beat)

Front 114

#114
The parasympathetic nervous sytem (PNS) dominates over the sympathetic nervous system (SNS) causing?

Back 114

the autonomic stimualation, slowing heart rate and causing vagal tone.
(PNS) dominates if you're healthy)

Front 115

#115
A sympathetic reflex initiated by increased blood in the atria is ______.

Back 115

Atrial (Bainbridge) Reflex

Front 116

#116
What are two things that the atrial bainbridge reflex does?

Back 116

1. Causes stimuation of the SA node2. Stimulates baroreceptors (measure pressure) in the atria, causing increased SNS stimualtion

Front 117

#117
What two hormones increase the heart rate?

Back 117

epinephrine
thyroxine

Front 118

#118
What two concentrations must be maintained for normal heart function?

Back 118

Intracellular ion concentrations
Extracellular ion concentrations

Front 119

#119
What disfunction causes~
*abnormally fast heart rate?
*results from such things as elevated body temperature, stress, some drugs, or heart disease
*May promote fibrillation

Back 119

Tachycardia

Front 120

#120
What disfunction causes~
*heart rate slower than 60 beats per minute
*from low body temperature, certain drugs, parasympathetic nervous system
*a desireable result of athletic conditioning

Back 120

Bradycardia
*persistant bradycardia in poorly conditioned individuals could result in inadequate circulation

Front 121

#121
What disfuction or condition is caused by~
*coronary atherosclerosis
*persistent high blood pressure
*multiple myocardial infarcts
*dilated cariomyopathy (DCM)

Back 121

Congestive heart failure (CHF)

Front 122

#122
The two fetal heart structures that bypass the pulmonary circulation are

Back 122

foramen ovale connect the two atria

ductus arteriosus connects the pulmonary trunk and the aorta

Front 123

#123
Name four age related changes affecting the heart~

Back 123

1, Sclerosis and thickening of valve flaps
2. Decline in cardiac reserve
3. Fibrosis of cardiac muscle - accumulation of small cells
4. Atherosclerosis - harding of the arteries, robs you of the elasticity, leads to persistance high blood pressure