Cardiovascular anatomy Flashcards
1
Q
Heart is bound anteriorly by the ______ and ______ cartilages
A
sternum, costal
2
Q
Heart is positioned between __, __, and ___ ribs
A
3, 4 , 5
3
Q
Heart is _______ to the diaphragm
A
Superior
4
Q
Least thick chamber of the heart
A
Right atrium (2mm)
5
Q
In the RV, ________ muscles and _________ _______ prevent eversion of TV
A
Papillary, chordae tendineae
6
Q
Most common cause of RV failure is ________
A
LV failure
7
Q
Atrial kick is ____ % increase in LVEDV
A
20%
8
Q
Which chamber of the heart is the thickest?
A
Left ventricle (8-15mm)
9
Q
Most severe condition that leads to most lost of atrial kick
A
a.fib (lose 20%)
mitral stenosis (lose 40%)
10
Q
Atrioventricular valves
A
Tricuspid, mitral
11
Q
Semilunar valves (3 cusps)
A
Aortic, pulmonic
12
Q
The left anterior descending (LAD) supplies the ____________, ______, _______, __________, and _______
A
Anterior 2/3 of interventricular septum
RBB
LBB
Papillary muscles of MV
Anterior lateral/apical LV walls
13
Q
The left circumflex (LCx) supplies __________ and _________
A
Left atrial wall
Posterior and lateral LV walls
14
Q
The RCA supplies ________ and ______ (90% of the time) and _______
A
SA and AV nodes (90% of the time)
Posterior third of the interventricular septum
15
Q
Coronary artery dominance. Right or left side dominant depending on which artery feeds the ______________
Right or left coronary artery. 50% receive from right, 50% receive from left or LCx
A
Posterior descending artery (PDA)
16
Q
The majority of veins drain into the __________ (collects 85% of blood from the LV)
A
Coronary sinus
17
Q
What is cannulated during CPB? When doing retrograde cardioplegia transfusion
A
Coronary sinus
18
Q
In a biventricular PM, the third lead goes through the ________ and sits in a coronary vein on the left side of the heart (the left ventricular lead)
A
Coronary sinus
19
Q
Increased HR
A
Chronotropy
20
Q
Increased force of contraction
A
Inotropy
21
Q
Increased rate of AV node discharge
A
Dromotropy
22
Q
Increased SNS activity causes:
A
Increased:
Chronotropy
Inotropy
Dromotropy
23
Q
Cardioaccelerator fibers: Preganglionic SNS fibers originiate from cells in the intermediolateral columns of:
A
T1-T4
24
Q
Sympathetic stimulation on cardiac innervation has a _______ onset
A
Gradual
25
The PNS tone typically _______ SNS tone at rest
exceeds
26
Increased PNS tone leads to ______ stimulation
Vagal
27
Right vagus innervates _____
SA node
28
Left vagus innervates ______
AV node
29
PNS/vagal effects on cardiac innervation have a ______ onset
Rapid
30
Which node has the slowest transmission of action potentials to allow for sufficient time for atria contraction before ventricular contraction?
AV node
31
Dominant PM of heart
SA node
32
SA node rate
60-100 bpm
33
AV node rate
40-60 bpm
34
Purkinje system rate
20-40 bpm
35
Difference between the electrical potential between inside and outside of cell
Resting Membrane Potential (RPM)
36
Internal voltage at which the cell depolarizes
Threshold potential
37
When RMP is closer to TP, the cell is _____ to depolarize
easier
38
When RMP is further from TP, the cell is ______ to depolarize
harder
39
Normal RMP
-90 mV
40
RMP is primarily regulated by ________
K+
41
Hypokalemia _______ RMP
Decreases
42
Hyperkalemia _______ RMP
Increases
43
Normal TP
-70 mV
44
TP is primarily regulated by ____
Ca+
45
Hypocalcemia _____ TP
decreases
46
Hypercalcemia _______TP
increases
47
Ventricular action potentials
Phase 0: Upstroke/depolarizarion
Na+ IN
48
Ventricular action potentials
Phase 1: Initial repolarization
Cl- IN
K+ OUT
49
Ventricular action potentials
Phase 2: Plateau
Ca+ IN
K+ OUT
50
Ventricular action potentials
Phase 3: Final repolarization
K+ OUT
51
Ventricular action potentials
Phase 4: Resting phase
Na+ OUT
52
Time during which a conducted action potential may not be evoked
Absolute refractory period
53
During the absolute refractory period, the membrane is greater than _____ mV
-60
54
The absolute refractory period lasts from Phase ____ to the middle of Phase ____
Phase 0
Middle of Phase 3
55
Time during the action potential when a second stimulus can result in another action potential with decreased amplitude
Relative refractory period
56
Relative refractory period last from middle of _____ to beginning of ______
Middle of phase 3
beginning of phase 4
57
The membrane potential is ____ to _____ mV during the relative refractory period
-60 to -90 mV
58
What does the relative refractory period coincide with on the ECG?
the T wave
59
What could happen if a shock was delivered during the relative refractory period?
V.tach/V.fib
60
In the Na+/K+ Pump, for the removal of every ___ Na+ ions, ___ K+ ions are returned
3, 2
61
What are some differences between the action potentials for the SA node vs for the ventricles?
In the SA node, there is no:
-Initial repolarization
-Plateau state
62
SA node action potential
Phase 4: Spontaneous depolarization
Na+ IN
Ca+ IN
63
SA node action potential
Phase 0: Depolarizaon
Ca+ IN
64
SA node action potential
Phase 3: Repolarization
K+ OUT
65
TP in SA node
-50 mV
66
What causes initial depolarization in SA node action potential vs Ventricular action potential?
SA node action potential:
Na+, Ca+ IN
Ventricular action potential:
Na+ IN
67
During what phase does the Na+/K+ Pump re-establish the Na+ and K+ gradients?
After repolarization, in Phase 4
68
How does the PNS influence cardiac conduction?
Decreases cardiac conduction
69
How does the SNS influence cardiac conduction
Increases cardiac conduction
70
How does myocardial ischemia affect cardiac conduction
Decreases cardiac conduction in affected cells
71
How do adrenergic agents (epi, NE, isuprel) affect cardiac conduction
Increase cardiac conduction
72
How do cholinergic agents (neostigmine) affect cardiac conduction
Decrease cardiac conduction
73
Two phases of SYSTOLE
Isovolumetric ventrucular contraction
Ventricular ejection
74
Pressures/Valves
Isovolumetric ventricular contraction
LV > LA ---> MV closure (S1)
MV closed
AV closed
75
Pressures/Valves
Ventricular ejection
LV > Aortic pressure ----> AV valve opens
MV closed
AV opened
76
Pressures/Valves
Rapid ventricular filling
LA pressure > LV pressure ----> MV opens
MV opened
AV closed
77
Pressures/Valves
Isovolumetric ventricular relaxation
Aorticl pressure > LV pressure ----> Aortic valve closed (S2)
MV closed
AV valve closed
78
Pressures/Valves
Reduced ventricular filling
LA pressure > LV pressure
MV opened
AV closed
79
80
What does the dictortic notch correspond to?
Aortic valve closure (S2), during isovolumetric relaxation
81
Cardiac output formula
CO = HR X SR
82
CO normal value
5-6 L/min
83
CI normal value
2.8-4.2 L/min/m2
84
Stroke volume formula
SV = EDV-ESV
85
Stroke volume is primarily determined by three factors
Preload
Afterload
Contractility
86
Normal SV
70-100ml/beat
87
2 factors that contribute to SV that we cannot control
Wall motion abnormalities
Valvular dysfunction
88
Most common clinical parameter related to afterload
SVR (systemic vascular resistance)
89
An EF of less than _____ % is associated with significant left ventricular impairment
40%
90
Name for the percentage of EDV that is ejected during systole
Ejection fraction
91
Normal EF
60-65%
92
Primary determinate of cardiac contractility
Ca+
93
The force of myocardial contraction is directly dependent on the magnitude of _____ influx during the phase ___ of depolarization
Ca+, phase 2 (plateau)
94
cAMP raises intracellular ____
Ca+
95
Beta-1 stimulation activates adenylate cyclase and converts ATP to ______
cAMP
96
Phosphodiasterase inhibitors (milrinone) prevent breakdown of intracelluar cAMP = raises ____ and improves cardiac contractility
Ca+
97
Volatile anesthetics ________ cardiac contractility by decreasing entry of ____ into cells during depolarization
Depress, Ca+
98
IV and local anesthetics have a cardiac _____ effect on contractility
Depressant
99
__________ (IV anesthetic) has the least direct depressant effect on cardiac contractility
Ketamine
100
Hypercalcemia
Beta 1 agonists
What do they do to cardiac contractility?
Increase cardiac contractility
101
CBF is about ___ - ___% of the cardiac output, or -____-____ml/mins
4-7%
225-250ml/min
102
LV coronary blood flow occurs mainly during _______ (80-90%)
Diastole
103
RV coronary blood flow occurs ____
throughout the cardiac cycle
104
Myocardium has a high metabolic demand of ____ -_____ O2 from hemoglobin
65-75%
105
Factors that increase myocardial oxygen demand
*Increased heart rate *
Increased preload
Increased afterload
Increased contractility
SNS stimulation
106
Factors that decrease supply of oxygen to myocardium
*Increased heart rate*
Increased end diastolic pressure
Decreased coronary diameter
Decreased extraction (anemia,
hypoxiemia)
Decreased MAP
107
Due to a high extraction rate, the only way to increase oxygen delivery is to increase _________ (supply)
Blood flow
108
What factor both increases myocardial oxygen demand and decreases its supply?
Increased heart rate
109
How would you increase supply and decrease demand?
Decrease heart rate
110
Coronary vasculature will autoregulate at a MAP of ___-___mmHg
60-140
111
Main determinant of CBF is
Diastolic blood pressure
b/c most of blood flow occurs during diastole
112
Main determinant of coronary perfusion pressure
Diastolic blood pressure
113
What reflexes cause vagal nerve stimulation?
Valsalva maneuver
Baroreceptor reflex
Oculocardiac reflex
Celiac reflex
Bezold-Jarisch reflex
114
Reflex that corrects for fluctuations in arterial blood pressure
Baroreceptor reflex
baroreceptors in carotid sinus (herings n.) aortic arch (vagus n.)
hypotension = increase SNS tone
hypertension = increase PNS tone
Ex: giving phenylephrine can cause
115
Inhibition of the baroreceptor reflex can occur with ______ and _____
Inhaled anesthetics
Aging process
116
Reflex: traction on extraocular muscles/conjunctiva/or orbital structures = hypotension and a reflex bradycardia
Oculocardiac reflex
Via vagal nerve stimulation
117
Reflex: traction on the mesentery or the gallbladder (stimulates CN X), causing bradycardia, apnea, and hypotension
indirectly stimulated from pneumoperitoneum
Celiac reflex
118
Reflex: Rapid decrease in preload activates mechanoreceptors within the LV
Afferent response to medulla causing profound hypotension, bradycardia, and possibly asystole
Bezold-Jarisch reflex
