Physiology of Cardiovascular System Flashcards
1
Q
What is the purpose of the cardiovascular system?
A
deliver oxygen and nutrients to organs, tissues, and cells and transport carbon dioxide for elimination
2
Q
How big is the heart?
A
the size of a man’s closed fist
3
Q
What is the function of the heart?
A
to pump enough blood to meet the body’s metabolic needs
4
Q
Where is the heart located?
A
Thoracic cavity in the mediastinum, above the diaphragm, behind the sternum, in front of the spine
5
Q
What is the top of the heart called?
A
base
6
Q
What is the bottom of the heart called?
A
Apex
7
Q
What are the 4 layers of the heart?
A
pericardium, epicardium, myocardium, endocardium
8
Q
Which layer is a double-walled sac that encloses the heart and serves as support and protection?
A
pericardium
9
Q
________ is found between the layers of the pericardium to minimize friction of the layers as they rub together with each heartbeat.
A
Pericardial fluid
10
Q
Which layer is the outermost layer that contains coronary arteries?
A
Epicardium
11
Q
Which layer is the middle and thickest layers that is made of muscle?
A
Myocardium
12
Q
Which layer is the thin innermost layer that forms the heart valves?
A
Endocardium
13
Q
What is the job of the heart?
A
to pump
14
Q
Which layer deals with the heart pump?
A
myocardium
15
Q
What is the job of the aorta, arteries, and arterioles?
A
distribution system
16
Q
What kind of walls are the aorta, arteries, and arterioles?
A
elastic and muscular (smooth)
17
Q
What is the job of the capillaries?
A
exchange vessels
18
Q
Skeleteal muscles have a ____ capillary network.
A
dense; 2,000-3,000 per square mm, 1 in 30-40 open at rest
19
Q
What is the job of the veins?
A
Collection and return system
20
Q
How much of the body’s blood volume do the veins hold?
A
64%
21
Q
What are the 4 things associated with the heart as a pump?
A
electrical activity, mechanical activity, cardiac output, and coronary blood flow
22
Q
______ is the rate and rhythm of cardiac muscle contraction PLUS.
A
Electrical activity
23
Q
______ is the contraction and coordination of cardiac muscle and heart valves EQUALS.
A
Mechanical activity
24
Q
______ pumps blood and oxygen through pulmonary and peripheral circulations REQUIRES.
A
Cardiac Output
25
_____ delivers blood and oxygen to heart muscle.
Coronary blood flow
26
What are the 2 main heart valves?
Semilunar valves and AV valves
27
What are the 2 semilunar valves?
pulmonic and aortic valve
28
Which valve is between the right ventricle and pulmonary artery?
pulmonic valve
29
Which valve is between the left ventricle and aorta?
Aortic valve
30
What are the 2 AV valves?
Tricuspid and Mitral valve
31
Which valve is between the right atrium and right ventricle?
Tricuspid
32
Which valve is between the left atrium and left ventricle?
Mitral
33
What type of muscle is striated and has intercalated disks?
Cardiac
34
What 2 filaments does the cardiac muscle have?
Actin and Myosin
35
_____ is a specialized cell membrane that separates cardiac muscle cells from one another.
Intercalated disks
36
What do the intercalated disks allow?
AP to easily pass from one cell to the next
37
Cardiac muscle is a _____ of many cardiac muscle cells.
syncytium
38
What happens when one cardiac muscle cell depolarizes?
all cells depolarize (allows for contraction)
39
Cardiac muscle is tuned for ____ metabolism.
Aerobic
40
What are the 4 characteristics of cardiac cells?
Automaticity, excitability, conductivity, and contractility
41
_____ is the ability to create an impulse without outside stimulation.
Automaticity
42
_____ is the ability to conduct an impulse to neighboring cells
Conductivity
43
_____ is the ability to depolarize.
Excitability
44
_____ is the ability to contract.
contractility
45
All but ____ are electrical characteristics.
Contractility
46
What characteristic is contractility?
mechanical
47
____ is the ability to spontaneously generate an AP.
automaticity
48
What are 2 examples of automaticity?
SA node, AV node
49
_____ rapidly transmit AP through heart.
Conductive properties
50
What are two examples of conductive properties?
Av bundle, Purkinje fibers
51
Pacemaker cells are ______.
automaticity
52
Specialized muscle cells are _____.
myogenic (self-excitable)
53
What does the ANS do to myocardial cells?
sends signals to speed up or slow down HR
54
What is the natural rate of discharge of SA node?
100 bpm
55
What is the normal heart rate?
70 bpm
56
The AV node discharges how many bpm?
40-60
57
Bundle branches and Purkinje fibers discharge how many bpm?
20-40
58
What is the primary pacemaker?
SA node
59
What is the secondary pacemaker?
AV node
60
What is the tertiary pacemaker?
Bundle branches and Purkinje fibers
61
What is the SA node resting membrane potential?
-55 to -60 mV
62
Automatic slow leakage of Na+ into SA nodal cells leads to spontaneous _______.
Depolarization
63
When other cardiac tissue generates a faster depolarization rate, it is known as _____.
Ectopic pacemakers
64
What is the resting membrane potential of cardiac muscle (non pacemaker cells)?
-85 to -95 mV
65
AP of cardiac muscle is caused by opening of fast ____ channels.
sodium
66
How long does the plateau last in a ventricular cardiac muscle?
.2-.3 seconds (15x longer than skeletal muscle)
67
What caused the plateau?
slow calcium channels
68
How long did the refractory period last in ventricles of cardiac muscle?
.25-.30 seconds
69
What caused the refractory period?
opening of potassium channels
70
In cardiac muscles, AP causes release of ____ from the sarcoplasmic reticulum.
Calcium
71
Calcium can flow through t-tubles _____ from extracellular fluid.
directly
72
Calcium release in cardiac cells leads to interaction of ____ and _____.
actin, myosin (excitation-contraction coupling)
73
What is the order for conduction through the heart?
Sa node, atrium, AV node, Purkinje fibers, ventricle
74
Why is there a delay of impulse at AV bundle?
the concentration of intercalated disk is much less
75
P wave = SA node _______.
Depolarization
76
Spread of depolarization across atria causes contraction of ____.
atria
77
What are the 4 phases of systole?
isovolumetric contraction, ventricular ejection, protodiastole, isovolumetric relaxation
78
______: ventricles contract but no blood is flowing.
Isovolumetric contraction
79
________: pulmonary and aortic valves open during ventricular contraction, at pressures of 8 mmHg (pulmonary) and 80 mmHg (aortic).
ventricular ejection
80
Left ventricular contraction generates a pressure of 120 mmHg in _____ and lasts .08-.12 seconds.
aorta
81
______: blood flow slows as pressures equalize.
protodiastole
82
_____: ventricles relax, valves close.
isovolumetric relaxation
83
____ valves are closed during systole.
AV
84
What happens to the ventricles during diastole?
they relax and fill with blood
85
What valves close during diastole?
Pulmonary and aortic
86
_____: AV valves open during systole
rapid filling phase
87
_____: flow into the ventricles slow as pressures equalize.
diastasis
88
Ventricular end-diastolic volume is ______mL.
110-120
89
What percent of ventricular filling occurs during diastole?
75%
90
____: contraction of atria supply remaining 20-30% of end-diastolic volume.
Atrial Kick
91
SV is ____ mL.
70
92
Ventricular end-systolic volume is ____ mL.
40-50
93
____ = SV / end diastolic volume
Ejection fraction
94
Heart pumps about _____% of EDV with each beat.
60
95
Work output of the heart is determined by ___ and ____.
pre;pad, afterload
96
_____= end-diastolic pressure in ventricles
preload
97
____= pressure in aorta or pulmonary artery
afterload
98
The venous return and end-diastolic volume regulate cardiac contractility and cardiac output known as?
Frank-Starling mechanism
99
Venous return is important regulator of ___.
CO
100
_____= amount of blood that flows from veins bak to right atrium each minute.
Venous return
101
Sympathetic stimulation increases ____ and contractility.
HR
102
Sympathetic stimulation can increase HR to ____bpm.
180-200
103
Parasympathetic stimulation _____ HR.
decreases
104
Fast HR can _____ CO because there is not enough time for heart to fill during diastole.
decrease
105
Alterations in ____ and _____ levels can significantly affect cardiac function.
Calcium, potassium
106
_____ nerve (parasympathetic) has minimal innervation of cardiac muscle.
Vagus
107
Parasympathetic stimulation deals with ______.
Acetylcholine
108
What slows HR, decreases rate of SA node discharge, and decreases excitability of fibers between SA node and AV node?
Parasympathetic stimulation
109
Acetylcholine increases permeability of SA and AV fibers to ____.
potassium
110
Potassium leaves cells ____ membrane potential.
lowering
111
Sympathetic stimulation deals with ____.
norepinephrine
112
What increases HR and contractility, rate of SA node discharge, rate of cardiac impulse conduction in all parts of heart, and force of atrial and ventricular contraction?
sympathetic stimulation
113
Norepinephrine increases permeability of ___ and _____.
sodium, calcium
114
Large Q waves greater than .04 seconds in duration may represent _____.
Myocardial Infarction
115
Flat, downsloping or depressed ST segments may indicate _____.
coronary ischemia
116
Abnormal T waves (depressed or peaked) can indicate ______ (ischemia or electrolyte abnormalities.
disease
117
_____: transport blood under high pressure; strong, elastic walls; rapid blood flow.
arteries
118
_____: act as "control valves"; smooth muscle in vascular walls; relate blood flow to capillaries through vasodilation and vasoconstriction; slower heart rate of slow.
arterioles
119
______: exchange oxygen, nutrients, and other substances between interstitial space; thin vascular walls.
capillaries
120
_____: collect blood from capillaries
venuoles
121
_____: transport blood back to heart; reservoir for blood; thin vascular walls; low pressure; rapid flow compared with capillaries and venuoles.
veins
122
___ contain some smooth muscle and are innervated by sympathetic fibers.
veins
123
Venoconstriction can _____ venous return to heart.
increase
124
Normal mean arterial pressure in systemic circulation?
93 mmHg
125
______ is difference between systolic and diastolic pressures.
Pulse pressure
126
Normal capillary pressure in systemic circulation?
17 mmHg
127
Normal venous pressure in systemic circulation?
0 mmHg at vena cava
128
Normal systolic pressure in pulmonary circulation?
25 mmHg
129
Normal diastolic pressure in pulmonary circulation?
8 mmHg
130
Normal mean arterial pressure in pulmonary circulation?
16 mmHg
131
Normal capillary pressure in pulmonary circulation?
7 mmHg
132
____ is determined by pressure gradient and vascular resistance.
Blood flow
133
______: resistance inversely related to radius of vessel.
Poiseulle's Law
