Chapter 17 Flashcards
Cardiovascular System - The Heart (132 cards)
1
Q
Cardiovascular System includes
A
- heart
- blood vessels
- blood
2
Q
what is the heart
A
Muscular organ, or pump, that delivers blood to the body; actually consists of two pumps that propel blood to two different circuits
3
Q
what is the shape of the heart
A
- Cone-shaped, with the point, or apex (bottom), pointing toward the left hip, and the flattened Base (top) facing the posterior rib cage
4
Q
how many chambers in the heart
A
4
5
Q
what is the apex of the heart
A
the point at the bottom of the heart
6
Q
what is the base of heart
A
the flattened top of the heart
7
Q
how big is the heart
A
- Relatively small, only about the size of a fist, and weighs from 250–350 grams (slightly less than 1 pound)
8
Q
what are the four chambers of the heart
A
- Right Atrium
- Left Atrium
- Right Ventricle
- Left Ventricle
9
Q
what is the epicardium
A
outermost thin layer of epithelial and connective tissue of the heart
10
Q
what is the myocardium
A
thick layer of cardiac muscle (sandwiched by the epicardium and endocardium)
- Electrical signals flow directly from cell to cell
- This layer contracts when the heart beats
11
Q
what is the endocardium
A
innermost thin layer of endothelial tissue of the heart wall
- Continuous with lining of blood vessels
12
Q
what are the layers of the wall of the heart
A
- epicardium
- myocardium
- endocardium
13
Q
what is the pericardium
A
fibrous sac that surrounds the heart
- Protects and anchors the heart
14
Q
what kind of tissue is the heart mostly made of
A
cardiac muscle tissue
15
Q
How many atria in the heart
A
2
16
Q
how many ventricles in the heart
A
2
17
Q
How many valves in the heart
A
4
18
Q
what are atrioventricular valves
A
- tricuspid valve
- bicuspid valve
19
Q
what are the semilunar valves
A
- pulmunary valve
- aortic valve
20
Q
what is the septum of the heart
A
muscular partition separating right and left sides of the heart
21
Q
*label the heart
slide 5
A
22
Q
what are the valves in the heart
A
- tricuspid valve
- bicuspid valve
- pulmonary valve
- aortic valve
23
Q
what is the purpose of the valves of the heart
A
prevent backflow
24
Q
the upper chambers of the heart are called
A
atria
25
the lower chambers of the heart are called
ventricles
26
the muscular partition separating right and left sides of the heart is called
the septum
27
what is the tricuspid valve
separates the upper and lower chambers on the right side
28
what is the bicuspid valve
separates the upper and lower chambers on the left side
29
what side is the tricuspid valve on
right side
30
what side is the bicuspid valve on
left side
31
where does the pulmonary valve go
towards the lungs
32
where does the aortic valve go
everywhere except to the lungs
33
what is the pulmonary circuit
- transports blood from heart to lungs and back to heart
- blood picks up O2, gets rid of CO2
- how blood gets oxygenated
34
what does the pulmonary circuit transport
transports deoxygenated blood from heart to lungs
transports oxygenated blood from lungs to heart
35
In the pulmonary circuit, blood does what
blood picks up O2, gets rid of CO2
36
what is the systemic circuit
- delivers blood to the rest of the body
- Transports blood to all parts of the body except the lungs, and back to heart
- O2 is delivered, CO2 waste is picked up
37
what does the systemic circuit transport
transports oxygenated blood from the heart to the rest of the body
transports deoxygenated blood from cells in the body back to the heart
38
In the systemic circuit, blood does what
provides oxygen to the cells of the body
39
What is the pattern of blood flow through the cradiovascular system - pulmonary circuit
1. Deoxygenated blood from the body travels through the vena cava to the right atrium of the heart.
2. Through the right A V valve into the right ventricle
3. Through the pulmonary semilunar valve into the pulmonary trunk, which divides into the right and left pulmonary arteries and travels to right and left lungs
4. Blood is oxygenated and CO2 is given up within pulmonary capillaries
5. Oxygenated blood travels through the pulmonary veins back to the heart, entering the left atrium
40
in thepulmonary circuit - Deoxygenated blood from the body travels ...
travels through the vena cava to the right atrium of the heart.
41
What is the pattern of blood flow through the cradiovascular system - systemic circuit
1. Oxygenated blood flows from left atrium through left A V valve into left ventricle
2. Oxygenated blood continues from the left ventricle through the aortic semilunar valve into the aorta
3. Through branching arteries and arterioles to tissues
4. Through the arterioles to capillaries
5. Within capillaries, nutrients and oxygen are delivered and wastes are picked up
6. From capillaries into venules and veins
7. To the vena cava and into the right atrium
42
veins carry what kind of blood in the pulmonary circuit
oxygenated
43
the pulmonary artery carries what kind of blood
deoxygenated
44
veins carry what kind of blood in the systemic circuit
deoxygenated
45
the pulmonary artery carries what kind of blood
deoxygenated
46
for each trip around the body, blood passes through the heart how many times
twice
47
deoxygenated blood goes through which side of the heart
right side
48
oxygenated blood goes through which side of the heart
left side
49
what kind of blood goes through the right side of the heart
deoxygenated
50
what kind of blood goes through the left side of the heart
oxygenated
51
Label Slide 10/11 - understand what's going on
52
the heart maintains homeostasis of what
blood pressure
53
what affects blood pressure
Rate and force of heart’s contractions influence blood pressure and blood flow to organs
54
what is blood pressure
the pressure that blood exerts on the blood vessels
55
What are the great vessels
- Major System Veins
- Pulmonary Trunk
- Pulmonary Veins
- Aorta
56
What are the Major System Veins
- Superior Vena Cava
drains deoxygenated blood from most veins superior to the diaphragm
- Inferior Vena Cava
drains deoxygenated blood from most veins inferior to the diaphragm. Both empty into the posterior aspect of the right atrium.
57
What is the pulmonary trunk
Receives deoxygenated blood from the right ventricle; located on the anterior side of the heart; splits into the Right and Left Pulmonary Arteries, which bring deoxygenated blood to the lungs
58
what are pulmonary veins
Oxygenated blood returns to the heart through four pulmonary veins—two from each lung that drain into the posterior part of the left atrium
59
what is the aorta
Supplies the entire systemic circuit with oxygenated blood; largest and thickest artery in the body; stems from the left ventricle as the Ascending Aorta, then curves to the left and makes a U-turn as the Aortic Arch
60
What is the difference between the superior vena cava and the inferior vena cava
superior drains blood from veins above the diaphragm and inferior drains blood from below the diaphragm
61
how many pulmonary veins come from each lung
2
62
where do pulmonary veins drain
into the posterior part of the atrium
62
label the external anatomy of the heart (front)
slide 15
63
what is the largest and thickest artery in the body
aorta
64
label the external anatomy of the heart (back)
slide 17
65
the right atrium has what qualities
- large
- thin walled
- located anteriorly
66
the left atrium has what qualities
- smaller
- thick walled
- located posteriorly
- make up most of heart's base and posterior surface
67
atria are separated by
a thin interatrial septum
68
the right ventricle has what qualities
- wider
- thinner walls than the left
- less resistance against which to pump
- crescent shaped chamber
69
the left ventricle has what qualities
- three times thicker walls
- pumps against much greater resistance
- circular shaped chamber
70
ventricles are separated by
interventricular septum
71
label internal anatomy of the heart
slide 20
72
which valves open together
Atrioventricular
- tricuspid
- bicuspid
Semilunar
- pulmonary
- aortic
73
which chambers contract together
the atria
the ventricles
74
what is the cardiac conduction system
Three cell populations in the heart are capable of spontaneously generating action potentials and setting the pace of the heart; makes up about 1% of the total number of cardiac muscle cells
75
what are pacemaker cell action potentials
Result from a reversal in membrane potential from about -60 m V to about +10 mV of unequal concentrations of calcium, sodium, and potassium ions moving through voltage-gated channels
76
the pacemaker cell action potentials result from a reversal in membrane potential from _________ to __________
-60 mV to +10 mV
77
what are the phases of the cardiac conduction stem
- slow initial depolarization phase
- full depolarization phase
- repolarization phase
- minimum potential phase
78
cardiac conduction system - what is the slow initial depolarization phase
Begin in a hyperpolarized state of about −60 m V; hyperpolarized membrane triggers voltage-gated H C N channels to begin to open; more sodium ions leak in than potassium ions leak out
More cations leak in than leak out through HCN channels in the plasma membrane, causing the membrane to slowly depolarize to threshold
79
cardiac conduction system - what is the full depolarization phase
When membrane reaches a threshold value of −40 m V, voltage-gated calcium ion channels open, calcium ions enter the cell which causes the membrane to fully depolarize
At threshold, voltage-gated Ca2+ channels open, and Ca2+ enter the cell, causing the membrane to fully depolarize
80
cardiac conduction system - what is the repolarization phase
Calcium ion channels are time-gated for closing so after about 100–150 m sec they begin to close; voltage-gated potassium ion channels begin to open; potassium ions exit the cell, and the membrane begins to repolarize
Ca2+ channels close and voltage gated K+ channels open, causing K+ outflow and repolarization
81
cardiac conduction system - what is the minimum potential phase
Potassium ion channels remain open until the membrane reaches its minimum potential; membrane is hyperpolarized, which triggers potassium ion channels to begin closing; the H C N channels begin to open, and the cycle begins again
K+ channels remain opne, and the membrane hyperpolarizes. This opens HCN channels and the cycle repeats
82
label cardiac conduction system
slide 27
slide 29
83
what is the sinoatrial node
Located in the right atrium inferior and lateral to the opening of the superior vena cava
node which causes the atria to contract
84
what is the atrioventricular node
Cluster of pacemaker cells located posterior and medial to the tricuspid valve
node which causes ventricles to contract
85
what is the cardiac cycle
The sequence of events that takes place within the heart from one heartbeat to the next
86
label nodes
slide 30
87
what are sinus rhythms
Electrical rhythms generated and maintained by the S A node
88
what pacemaker node sets the heart rate
SA Node
89
what is an ectopic pacemaker
Group of other cells attempt to pace the heart resulting in irregular rhythms
90
what are purkinje fibres
branches of specialized nerve cells. They send electrical signals very quickly to your right and left heart ventricles.
91
what is the conduction pathway through the heart
1. S A node generates an action potential, which spreads to atrial cells and the A V node
2. After the A V node delay, the action potential is conducted to the A V bundle and then to the right and left bundle branches
3. The action potential spreads from the bundle of His branches along the Purkinje fibers to the contractile cells of the ventricles
92
what is the bundle of his
an elongated segment connecting the AV Node and the left and right bundle branches of the septal crest
93
label conduction system
slide 32
94
what does ecg stand for
electrocardiogram
95
what is an electrocardiogram
Graphic depiction of the electrical activity occurring in all cardiac muscle cells over a period of time; EKG (or Elektrokardiogramm) is German
96
how is an ecg done
- Electrodes on the surface of the skin (six on the chest and two on each extremity) record changes in electrical activity from the heart that register on the E C G as Waves
- Only measure changes in electrical activity and only from contractile cells
97
what is the p wave
Represents the depolarization of all cells in the atria except the S A node; flat segment before the P wave represents depolarization of the S A node
98
what is the QRS Complex
Represents ventricular depolarization; much larger in magnitude because of the size differences between the atria and ventricles; atrial repolarization occurs at this time but is obscured by the large Q R S complex
99
what is the t wave
Represents ventricular repolarization; some pathologies may cause the T waves to become inverted as a result of the functional changes in the electrical activity
100
label ecg wave
slide 34
101
on an ecg - periods between the waves represent
Periods between the waves represent important action potential phases;
102
___________ include a component of at least one wave
intervals
103
___________ do not include any wave componenets
segments
104
on an ecg - R-R interval
Represents the entire duration of the generation and spread of an action potential through the heart; determines heart rate
105
on an ecg - Q-T interval
Ventricular cells are undergoing action potentials
106
on an ecg - S-T segment
Recorded during the plateau phase of the ventricles and no net changes occur in electrical activity; elevations or depressions are seen with many clinical conditions, such as myocardial infarction
107
what is dysrhythmia
Disturbance in the electrical rhythm of the heart
108
an ecg provides information about ...
structure, conduction pathways, and overall health of the heart
109
when does ventricular repolarization happen - ecg
T wave - the cause of it
110
when does atrial repolarization happen - ecg
during QRS Complex - can't see it because it happens at the same time
111
what are the basic patterns of dysrhythmias
- disturbances in heart rate
- disturbances in conduction pathways
- fibrillation
112
what are types of disturbances in heart rate
- bradycardia
- tachycardia
113
what is bradycardia
disturbance in heart rate
60 bpm or less
114
what is tachycardia
disturbance in heart rate
100 bpm or more
115
what is a kind of disturbance in conduction pathways - ecg
heart block
116
what is heart block - ecg
disturbance in conduction pathways
Blockages along the conduction system. Often found at the A V node resulting in longer P-R interval and/or extra P waves; also at the right or left bundle branch which widen the Q R S complex
117
what is fibrillation - ecg
electrical activity goes haywire
118
what are types of fibrillation
- atrial fibrillation
- ventricular fibrillation
- asystole
119
what is asystole
flat-lining where there is no electrical activity to reset
120
what is ventricular fibrillation
immediately life-threatening; Treated with Defibrillation, or a shock to the heart to throw cells into their refractory period;
121
what is atrial fibrillation
multiple chaotic electrical signals fire simultaneously in the atria, disrupting the normal conduction pathway and leading to an irregular rhythm.
122
when do the AV valves close
during S1
122
when do the SL valves close
during S2
123
what is systole
This is the phase of the cardiac cycle when the heart muscles contract.
123
what is diastole
This is the phase of the cardiac cycle when the heart muscles relax. During ventricular diastole, the heart chambers fill with blood from the atria.
124
why are sounds of the heart heard slightly away from the actual valves
because sound waves are carried away from the valves by blood moving through the ventricles or vessels
125
S1 is typically ________ and ________ than S2, although ________ in frequency
S1 is typically **longer** and **louder** than S2, although **lower** in frequency
126
where is the aotric valve sound heard
second intercostal space, right sternal border
127
where is tricuspid valve sound heard
fifth intercostal space, left sternal border
128
where is bicupid valve sound heard
fifth intercostal space, mid-clavicular line
129
where is the pulmonary valve sound heard
second intercostal space, left sternal border
