Heart Flashcards
(160 cards)
1
Q
What side of the heart is the pulmonary circuit?
A
Right
2
Q
What side of the heart is the systemic circuit?
A
Left
3
Q
What is the middle of the heart called?
A
Septum
4
Q
Why are the two circuits kept separate?
A
To prevent dilution of blood
5
Q
What type of blood enters the left side of the heart?
A
Oxygenated
6
Q
What type of blood enters the right side of the heart?
A
Deoxygenated
7
Q
Where does the left side of the heart send the blood?
A
The organs
8
Q
Where does the right side of the heart send the blood?
A
The lungs
9
Q
Where is the heart located?
A
In the mediastinum between the lungs
10
Q
What two parts make the heart?
A
Base & Apex
11
Q
What direction does the heart tilt?
A
To the left
12
Q
What is the divot the heart makes on the lung called?
A
Cardiac impression
13
Q
What type of membrane is the pericardium?
A
Serous
14
Q
What is the function of the pericardium?
A
Allows muscle movement & prevents friction
15
Q
What are the two parts of the pericardium?
A
Parietal & visceral
16
Q
What is another name for the visceral pericardium?
A
epicardium
17
Q
What is the pericardial cavity?
A
Space inside the pericardial sac filled with fluid
18
Q
What is pericarditis?
A
inflammation of the pericardium (painful)
19
Q
What are the three layers of the heart wall?
A
epicardium, myocardium, and endocardium
20
Q
What is the endocardium?
A
Smooth inner lining of heart
21
Q
What is the myocardium?
A
the middle layer, 95% of heart
22
Q
What is the myocardium’s function?
A
provide structural support and attachment and electrical insulation
23
Q
What are the 4 heart chambers?
A
right atrium, left atrium, right ventricle, left ventricle
24
Q
What are the atria separated by?
A
interatrial septum
25
What are the ventricles separated by?
interventricular septum
26
What is the function of the atria?
receive blood returning to the heart
27
Where are the auricles located?
Surface of atria
28
What is the function of the ventricles?
Pump blood into arteries
29
What is systole?
contraction
30
What is diastole?
relaxation
31
What are the pectinate muscles?
grooves in heart
32
What is the pulmonary trunk?
blood vessel to the lungs
33
What is the aorta?
blood vessel to the system
34
What side is the myocardium thicker on? Why?
The left side, more force to pump out to the rest of the body
35
What are trabeculae carnae?
internal ridges that prevent ventricles from sticking together
36
What is the coronary sulcus?
groove that separates the atria and ventricles
37
What is the interventricular sulcus?
Divides right and left ventricles
38
What is the right AV valve?
Tricuspid
39
What is the left AV valve?
Mitral/bicuspid
40
What are the chordae tendinae?
cords that connect AV valves to papillary muscle
41
What do the papillary attachments do?
Distribute stress, coordinate timing of electrical conduction, and provide redundancy
42
What do the semilunar valves control?
blood flow into arteries
43
Where is the pulmonary semilunar valve?
between right ventricle and pulmonary trunk
44
Where is the aortic semilunar valve?
Between left ventricle and aorta
45
What happens to the valve pockets in diastole?
They fill with blood due to gravity
46
What happens to the valve pockets in systole?
blood pushes pocket shut and creates an opening
47
What happens to the valves in ventricular diastole?
semilunars close and AV open
48
What happens to the valves in ventricular systole?
semilunars open and AVs close
49
What direction does an artery take blood?
away from heart
50
What direction does a vein take blood?
toward heart
51
What are the only arteries with deoxygenated blood?
the 2 from the pulmonary trunk
52
Where does the left coronary artery branch off of?
the ascending aorta
53
What does the LCA supply blood to?
both ventricles and anterior interventricular septum
54
Where does the circumflex branch of the LCA go?
around the left side of the heart in the coronary sulcus
55
What does the circumflex branch give off?
the left marginal branch
56
What does the circumflex branch supply?
the left atrium and posterior wall of left ventricle
57
What does the right coronary artery branch off of?
the ascending aorta
58
What does the RCA supply?
right atrium and SA node
59
What does the right marginal branch supply?
the lateral aspect of right atrium and ventricle
60
What does the posterior interventricular branch supply?
posterior walls of ventricles
61
What is coronary artery disease?
constriction of the coronary arteries
62
What are some causes of coronary artery disease?
hypertension, diabetes, atherosclerosis
63
How do the arteries get obstructed?
bulging mass grows from atheromas and fatty plaques
64
What is a myocardial infarction?
heart attack- interruption of blood supply to the heart
65
What is angina pectoris?
Chest pain from ischemia (lactic acid buildup)
66
Why does lactic acid get produced?
the myocardium switches to anaerobic fermentation
67
What are the 3 main inputs of the coronary sinus?
great cardiac vein, posterior interventricular vein, and left marginal vein
68
Where does the great cardiac vein collect blood from?
Anterior portion of the heart
69
Where does the posterior interventricular vein collect blood from?
posterior portion of heart
70
Where does the coronary sinus empty into?
Right atrium
71
What are the nuclei of cardiocytes surrounded by?
glycogen
72
What allows electrical signals to be passed between cells?
gap junctions
73
What does myoglobin store?
oxygen
74
What is the limiting factor in what cardiac muscle cells can use as a fuel?
amount of oxygen
75
Do cardiomyocytes fatigue?
No
76
What is a contractile cell?
A cell that physically does the contracting
77
What is a conductile cell?
a cell that sends the signal
78
Where does the electrical signal start?
the SA node
79
Where is the SA node?
right atrium
80
Where does the signal travel after the SA node?
the AV node
81
Where does the signal travel after the AV node?
the AV bundle brances
82
Where does the signal travel after the AV bundle branches?
the Purkinje fibers
83
Where does the signal go after the Purkinje fibers?
through gap junctions and from cell to cell
84
What does the system need to initiate contraction?
Calcium
85
Where is calcium stored?
the sarcoplasmic reticulum
86
What needs to happen in order to release Ca?
An action potential
87
What do sympathetic nerves do to HR?
increase
88
What do parasympathetic nerves do to HR?
lower-vagus
89
What is normal heart rhythm called?
sinus rhythm
90
What is ectopic focus?
A region of spontaneous firing other than the SA node
91
Does the SA node have a stable resting potential?
No
92
What voltage does the SA node potential start? What happens to it?
Starts at -60 mV, drifts upwards due to slow Na influx
93
When do the voltage gated fast calcium and sodium channels open?
at -40 mV
94
When do K channels open (pacemaker)?
At 0 mV
95
What does the SA node firing cause?
Heartbeat
96
What does the Na/K pump require?
ATP
97
How much Na + K does the pump pump?
3 Na outside the cell and 2 K in the cell
98
What is the cardiocyte resting potential?
-90 mV
99
What are the 3 phases of cardiocyte action potential?
Depolarization, plateau, and repolarization
100
Where does the depolarization phase peak? (contractile)
+30 mV
101
What channels open at +30 mV?
Slow calcium
102
What channels open to cause repolarization?
K
103
What cells are in the cardiocyte action potential?
contractile
104
What are the 3 components of an ECG graph?
P wave, QRS complex, T wave
105
What happens during the P wave?
SA node fires, atria depolarize
106
What happens during the QRS complex?
Ventricles depolarize, atria repolarize (unseen)
107
What happens during the ST segment?
ventricular systole
108
What happens during the PR interval?
atrial systole
109
What happens during the T wave?
ventricles repolarize and relax
110
What causes Vfib?
electrical signals traveling randomly
111
What condition is marked by Vfib?
Heart attack
112
When ventricle pressure is low, what happens to the AV valves?
they are open
113
When ventricle pressure is high, what happens to the AV valves?
they close and blood goes to the aortic valve (semilunar)
114
What is valvular insufficiency?
failure of a valve to prevent regurgitation
115
What is valvular stenosis?
Cusps are stiffened by scar tissue
116
What is a mitral valve prolapse? Symptoms?
When the cusps bulge into atria during ventricular contraction; chest pain and shortness of breath
117
What does S1 sound like?
lubb
118
What causes S1?
Closure of AV valves
119
What does S2 sound like?
dubb
120
What causes S2?
closure of semilunar valves
121
What are the phases of the cardiac cycle?
ventricular filling, isovolumetric contraction, ventricular ejection, isovolumetric relaxation
122
What happens in ventricular filling?
Ventricles expand, AV valves open, EDV is achieved (130 m/l)
123
What happens in isovolumetric contraction?
Atria relax, ventricles begin to contract, AVs close, S1 occurs
124
What happens in ventricular ejection?
SL valves open, stroke volume (54% of EDV), remaining blood is ESV
125
What happens in isovolumetric relaxation?
T wave ends, ventricles expand, SL close, S2 occurs, no blood taken in
126
About how long is the cardiac cycle?
less than a second, ~70 bpm
127
What must both ventricles eject?
the same amount of blood
128
What is congestive heart failure?
failure of either ventricle to eject blood effeciently
129
What does left ventricular failure cause?
pulmonary edema
130
What does right ventricular failure cause?
systemic edema
131
What is cardiac output?
amount ejected in 1 minute
132
What is the formula for cardiac output?
HR x SV
133
What is a normal volume of blood?
~5 L
134
What is the cardiac reserve?
Difference between maximum and resting CO
135
What is tachycardia?
resting HR above 100
136
What is bradycardia?
resting HR below 60
137
What are positive chronotropic agents?
factors that raise HR, symp. nerves
138
What are negative chronotropic agents?
factors that lower HR, parasymp. nerves
139
What is vagal tone?
steady background firing rate, 70-80 bpm
140
What part of the brain receives cardiac input?
medulla oblongata
141
What is a baroreceptor? Where are they?
signal cardiac center, located in aorta and internal carotid arteries
142
What 3 variables govern stroke volume?
preload, contractility, afterload
143
What do preload and contractility do?
increase stroke volume
144
What does afterload do?
decreases stroke volume
145
What is preload?
amount of tension in ventricular myocardium before contraction
146
What does exercise do to preload?
stretches myocardium and increases contraction (more stretch = harder contraction)
147
What is the Frank-starling law?
SV is proportional to EDV
148
What is contractility?
how hard the myocardium contracts
149
What do positive inotropic agents do?
increase contractility
150
What can hypercalcemia cause?
strong, prolonged contractions
151
What does digitalis do?
raise calcium levels and contraction strength
152
What do negative inotropic agents do?
reduce contractility
153
What can hyocalcemia cause?
weak, irregular heartbeat
154
What can hyperkalemia cause?
reduced strength of myocardial action potentials
155
What is afterload?
sum of all forces opposing ejection of blood from ventricle
156
What is the largest part of afterload?
blood pressure in aorta and pulmonary trunk
157
What does hypertension do (afterload)?
increase afterload and oppose ventricular ejection
158
What can also increase afterload?
anything that impedes arterial circulation
159
What is Cor pulmonale?
right ventricular failure due to obstructed pulmonary circulation
160
What effect does exercise have on cardiac output? Why?
increases, bc increase in HR and SV, ventricular hypertrophy
