Chapter 18 - The Heart Flashcards
1
Q
the cardiovascular system is made up of
A
the heart and blood vessels
2
Q
what makes up the circulatory system
A
the heart, blood vessels, and blood
3
Q
what are the two divisions of the circulatory system
A
pulmonary circuit and systemic circuit
4
Q
pulmonary circuit
A
brings blood to the lungs to be oxygenated
5
Q
the pulmonary circuit pumps blood from which side of the heart
A
right
6
Q
arteries
A
move blood away from the heart
7
Q
what gases are exchanged in the lungs through the pulmonary system
A
CO2 out, O2 in
8
Q
way of deoxygenated blood and oxygenated blood in the pulmonary system
A
deoxygenated blood is pumped by the right side of the heart into the lungs, oxygenated blood arrive on the left side of the heart
9
Q
systemic circuit
A
delivers oxygenated blood to the body via systemic arteries
10
Q
the systemic circuit pumps blood from which side of the heart
A
left
11
Q
way of oxygenated and deoxygenated blood in the systemic circuit
A
oxygenated blood is pumped by the left side of the heart through the body, then deoxygenated blood returns to the right side of the heart
12
Q
atria
A
veins that receive blood returning to the heart from the body
12
Q
location of atria
A
two superior chambers of the heart
13
Q
the right atrium receives blood from circulation, the left atrium receives blood from circulation
A
right atrium receives blood from systemic circulation, left atrium receives blood from pulmonary circulation
14
Q
ventricles
A
pump blood into arteries
15
Q
ventricles are located
A
in the two inferior chambers of the heart
16
Q
the right ventricle pumps blood into , the left ventricle pumps blood into
A
the right ventricle pumps blood into the pulmonary artery, the left ventricle pumps blood into the aorta
17
Q
flow of blood through the right side of the heart
A
- Deoxygenated blood arrives at the right atrium via systemic veins
- Right Atrium pumps blood to the right ventricle
- Right Ventricle pumps blood to pulmonary artery then the lungs and body
18
Q
two main systemic veins
A
superior and inferior cava
19
Q
flow of blood through the left side of the heart
A
- oxygenated blood arrives at the left atrium via pulmonary arteries
- Left atrium pumps blood to the left ventricle
- Left ventricle pumps blood into the aorta and systemic circulation of the body
20
Q
function of heart valves
A
ensure the one way flow of blood
21
Q
when do heart valves open
A
due to the pressure gradient created by heart beats
22
Q
Atrioventricular Valves ensure blood flow from to .
A
from the atria to the ventricles
23
Q
right AV valve is also called
A
tricuspid valve
24
left AV valve is also called
bicuspid or mitral valve
25
why do AV valves stay closed
to prevent backflow when ventricles contract
26
chordae tendineae
attach AV valves to floor of ventricles, attach to papillary muscles
27
blood flow
vein to atrium to ventricle to artery
28
semilunar valves are between
ventricles and great arteries
29
pulmonary semilunar valves are between
right ventricle and pulmonary artery
30
aortic semilunar valve is between
left ventricle and aorta
31
semilunar valves only open upon
ventricular contraction
32
cardiac cycle
one complete cycle of contraction and relaxation of all four heart chambers
33
the heartbeat lasts approximately
1 second
34
systole
cardiac contraction
35
diastole
cardiac relaxation
36
general reference to systole/diastole of the heart means
the ventricles
37
which chambers drive the cardiac cycle
ventricles
38
in ventricular diastole, blood flows from
atria to ventricles
39
AV valves close when
blood pressure in ventricles push them close
40
the first heart sound occurs
when AV valves close
41
in Ventricular systole, blood flows
into arteries
42
in ventricular diastole, pressure increases/decreases
decreases
43
in ventricular systole, pressure increases/decreases
increases
44
Semilunar valves are pushed open when
ventricles contract
45
semilunar valves close when
the blood pressure in arteries push them closed
46
the second heart sound occurs
when the blood pressure in arteries push semilunar valves closed
47
what sound does S1 make
lub
48
what sound does S2 make
dub
49
the third heart sound occurs
when the mitral valve opens and blood hits the wall of the left ventricle
50
what sound does S3 make
ta
51
the third heart sound is only heard
in people under 30
52
what phases of the cardiac cycle occur in ventricular diastole
ventricular filling and isovolumetric relaxation
53
what phases of the cardiac cycle occur in ventricular systole
ventricular ejection and isovolumetric contraction
54
three phases of ventricular filling
rapid ventricular filling, diastasis, atrial systole
55
end-diastolic volume
volume of blood in each ventricle at the end of atrial systole
56
end-diastolic volume amount
130 mL
57
in what phase of the cardiac cycle does the atria first relax
isovolumetric contraction
58
in what phases of the cardiac cycle does ventricles depolarize
isovolumetric contraction
59
why do ventricles not yet eject blood in isovolumetric contraction
blood pressure in arteries is too high to open the Semilunar valves
60
in what phase of cardiac contraction does the ventricles fully contract
ventricular ejection
61
in what phase of the cardiac cycle do semilunar valves open
ventricular ejection
62
ventricular ejection phases
rapid ejection and reduced ejection
63
end systemic volume
amount of blood left after ventricular ejection
64
what is stroke volume
the amount of blood ejected from the ventricles
65
how is end-systolic volume calculated
EDV-SV
66
end systolic volume releases how much blood?
60 mL
67
which phase of the cardiac cycle is the longest
ventricular ejection
68
in which phase of the cardiac cycle do ventricles begin to expand
isovolumetric relaxation
69
in what phase of the cardiac cycle do semilunar valves close
isovolumetric relaxation
70
ventricles receive the same/a different amount of blood
the same
71
cardiomyocytes
cardiac muscle cells
72
characteristics of cardiomyocytes
short cells, involuntary, striated, single nuclei, branched, fibrosis repair, joined by intercalated discs
73
striation
regular arrangement of thick and thin filaments
74
interdigitating folds
folds interlocking with the folds of adjoining intercalated discs
75
interdigitating folds allow for
increased contact surface area between cardiomyocytes
76
types of junctions between cardiomyocytes
desmosomes and gap junctions
77
desmosomes in cardiac muscle
prevent cardiomyocytes from pulling apart
78
gap junctions in cardiomyocytes
assist in depolarization of ventricles and simultaneous contraction of entire myocardium
79
cardiac muscle uses what type of metabolism
aerobic respiration
80
why is aerobic respiration used in cardiac muscle
high myoglobin, glycogen, and mitochondria content
81
cardiac conduction system
coordinates the heartbeat pathways that travel through the myocardium
82
steps of cardiac conduction
SA node, Atria, AV node, AV bundle, subendocardial conduction network
83
the internal pacemaker is the
SA node
84
location of the SA node
right atrium, near superior vena cava
85
the right side of the heart receives blood from the circuit and sends blood to the circuit
systemic, pulmonary
86
the left side of the heart receives blood from the circuit and sends blood to the circuit
pulmonary, systemic
87
electrical signals are prevented from reaching ventricles from the atria because of
a fibrous skeleton
88
the electrical gateway to the ventricles is the
AV node
89
the AV node is located within
the interatrial septum
90
the AV bundle is also called
bundle of His
91
the AV bundle branches or is one
branches
92
subendocardial conduction network
nerve-like projections from the apex into the ventricles
93
cardiomyocytes pass electrical signals through
gap junctions
94
in which phase of the cardiac conduction system does the ventricles contract
subendocardial conducting network
95
cardiac rhythm
rate at which heart beats
96
sinus rhythm
normal HR triggered by SA node
97
sinus rhythm fires every
0.8 sec
98
sinus rhythm heart rate
70-80 bpm
99
sinus rhythm functions best when under the influence of
the vagus nerve
100
ectopic focus
region of spontaneous firing other than the SA node
101
nodal rhythm
heart rate generated by AV node
102
nodal rhythm heat rate
40-50 bpm
103
pacemaker potential
gradual depolarization of SA node
104
RMP of pacemaker potential
-60 mV
105
SA node Action potential steps
threshold voltage reached, voltage gated Ca and Na channels open, depolarization, repolarization
106
threshold voltage of SA node action potential
-40 mV
107
depolarization voltage of SA node AP
0 mV
108
cardiomyocytes RMP
-90 mV
109
cardiomyocytes AP start with
SA node stimulation
110
phases of AP in cardiomyocyte
depolarization, plateau phase, repolarization
111
cardiomyocyte depolarization voltage
30 mV
112
Plateau Phase
contraction sustained in cardiomyocyte by expelling blood from chamber
113
longest phase of cardiomyocyte AP
plateau phase
114
purpose of the absolute refractory period for cardiomyocytes
allows for complete contraction and relaxation
115
heart rate
number of heart beats per minute
116
cardiac output
volume of blood ejected by one ventricle per minute
117
cardiac output formula
HR x SV
118
stroke volume
amount of blood pumped by ventricle with each heartbeat
119
cardiac reserve
difference between max and resting Cardiac Output
120
tachycardia
fast HR
121
tachycardia bpm
over 100 bpm
122
bradycardia
slow HR
123
bradycardia bpm
under 60 bpm
124
chronotropic agent
factor that changes HR
125
positive chronotropic
raises HR
126
negative chronotropic
lowers HR
127
preload
amount of tension in ventricular myocardium just before contraction
128
more ventricular stretch causes more which cause more
tension, contraction
129
preload increases/decreases SV
increases
130
frank starling law
SV is proportional to end-diastolic volume
131
contractility
how hard the myocardium contract for a preload
132
contractility increases/decreases SV
increases
133
inotropic agents
factors of contractility
134
positive inotropic agents
increased contractility by increased Ca
135
negative inotropic agents
decreased contractility by decrease Ca
136
afterload
sum of all forces opposing ejection of blood from ventricle
137
afterload increases/decreases SV
decreases
138
main cause of afterload
high BP in arteries
