HEART LECTURE Flashcards
1
Q
What is the cardiovascular system made up of?
A
the cardiovascular system is made up of the heart and the blood vessels
2
Q
What are the three types of blood vessels?
A
the three types of blood vessels are the veins, arteries, and capillaries
3
Q
What is the heart?
A
a four-chambered muscular pump
4
Q
What is the function of the arteries?
A
arteries are responsible for carrying blood away from the heart
5
Q
What is the function of the veins?
A
veins are responsible for carrying blood to the heart
6
Q
What are capillaries?
A
capillaries are tiny networks of veins and arteries that supply blood
7
Q
What are the two subdivisions of the cardiovascular system?
A
the cardiovascular system is divided into the pulmonary circuit and the systemic circuit
7
Q
What is the function of the pulmonary circuit?
A
the pulmonary circuit carries deoxygenated blood to the lungs for gas exchange and returns oxygenated blood to the heart
8
Q
Which side of the heart makes up the pulmonary circuit?
A
the right side of the heart makes up the pulmonary circuit
9
Q
Which vessels does the pulmonary circuit use in order to transport deoxygenated blood?
A
the pulmonary circuit uses the pulmonary arteries in order to transport deoxygenated blood to the lungs
10
Q
Which vessels does the pulmonary circuit use in order to transport oxygenated blood?
A
the pulmonary circuit uses pulmonary veins in order to transport oxygenated blood to the heart
11
Q
What is the function of the systemic circuit?
A
the systemic circuit is responsible for supplying oxygenated blood to the entire body and returning deoxygenated blood to the heart
12
Q
Which side of the heart makes up the systemic circuit?
A
the left side of the heart makes up the systemic circuit
13
Q
Which vessel does the systemic circuit use to supply oxygenated blood to the body?
A
the systemic circuit utilizes the aorta to supply oxygenated blood to the body
14
Q
Which vessels does the systemic circuit use in order to return deoxygenated blood to the heart?
A
the systemic circuit uses the superior/ inferior vena cava to return deoxygenated blood to the heart
15
Q
Where is the heart located?
A
the heart is located in the mediastinum of the thoracic cavity (between the lungs)
16
Q
How large is the heart?
A
the heart is approximately the same size as your fist; weighing ~10oz
17
Q
What is the positioning of the heart?
A
the inferior portion of the heart (the apex) is slightly tilted left
18
Q
What is the pericardium?
A
the pericardium is the tough fibrous tissue sac that encloses the heart
19
Q
What fluid is the pericardium filled with?
A
the pericardium is filled with pericardial fluid
20
Q
What is the function of pericardial fluid?
A
pericardial fluid allows the heart to beat with relatively no friction
20
Q
What is the clinical condition: percarditis
A
pericarditis is an inflammation of the pericardium
21
Q
What is the cause of percarditis?
A
pericarditis is due to dryness of the membrane and increased friction during each heartbeat
22
Q
What are the three layers of the heart?
A
the three layers of the heart are the epicardium, myocardium, and endocardium
23
What is the epicardium layer of the heart?
the epicardium is the thin, smooth and moist serous layer; most superficial
23
What is the myocardium layer of the heart?
the myocardium is the thick, cardiac muscle of the heart; middle layer
23
Where does the contraction of the heart occur?
contraction of the heart occurs in the myocardium
24
What is the endocardium layer of the heart?
the endocardium is the smooth, inner lining of the chambers and valves; most deep
25
Where are the right/ left atria located?
the right/ left atria are the most superior chambers of the heart; superior to the ventricles
26
What is the function of the right/ left atria
the right/ left atria receive blood returning to the heart and pump it into the ventricles
27
What is the function of the interatrial septum?
the interatrial septum is responsible for separating the right/ left atria from each other
27
Where are the right/ left ventricles located?
the right/left ventricles are the inferior chambers of the heart; inferior to the atria
28
What is the function of the right/ left ventricles?
the right/ left ventricles are responsible for pumping blood into the arteries
28
Describe the muscular walls of the atria.
the atria have thin muscular walls
29
Describe the muscular walls of the ventricles.
the ventricles have thick muscular walls; especially the left ventricle
30
Why is the left ventricle wall significantly thicker than its neighboring chambers?
the left ventricle wall is responsible for pumping the blood further away from the heart; requiring more force output
31
What is the interventricular septum?
the interventricular septum separates the right/ left ventricles
32
What is the function of the heart valves?
the heart valves ensure that blood flows in only one direction
33
What is the function of the atrioventricular valves?
the atrioventricular valves prevent backflow from the ventricles to the atria
34
What is another term for the right atrioventricular valve?
another term for the right atrioventricular valve is the tricuspid valves
35
What is another term for the left atrioventricular valve?
another term for the left atrioventricular valve is the bicuspid/ mitral valve
36
What does the acronym LAMB stand for?
the acronym "lamb" stands for "left atrium mitral/ bicuspid"
37
What are chordae tendineae?
chordae tendineae are string-like cords that attach the valves to papillary muscles of the floor of the ventricles
38
What is the function of the semilunar valves?
the semilunar valves are responsible for preventing backflow from the great arteries into the ventricles
39
How many cusps do the semilunar vales have?
the semilunar valves have three cusps
40
What is the first step of valve mechanics?
the first step of valve mechanics occurs when the ventricles relax and pressure drops; the semilunar valves close and the atrioventricular valves open allowing blood to flow into the ventricles from the atria
41
What is the second step of valve mechanics?
the second step of valve mechanics occurs when the ventricles contract and the atrioventricular valves close; pressure and the semilunar valves open causing blood to flow into the great arteries
42
What is the function of papillary muscles during the second step of valve mechanics?
the papillary muscles are responsible for contracting and pulling on the chordae tendineae to prevent prolapse
43
How many steps are there to valve mechanics?
valve mechanics is a two step process
44
What is a heart murmur?
a heart murmur is the regurgitation (backward flow) of blood through valves that are not functioning properly
45
Describe the pathway of blood in a way that starts and end in the right atrium.
- right atrium
- right atrioventricular valve
- right ventricle
- pulmonary semilunar valve
- pulmonary arteries
- lungs
- pulmonary veins
- left atrium
- left atrioventricular valve
- aortic semilunar valve
- aortic artery
- anatomical systems
- superior/ inferior vena cava
- right atrium
46
What is the function of the coronary circulation?
the function of the coronary circulation is to nourish the heart wall/ every cell in the myocardium
47
What makes up the coronary circulation?
the coronary circulation is made up of blood vessels
48
Describe the amount of time the heart beats over the course of one human life span.
the heart rate of the average person is 75 beats/ min for 80 years; at rest the heart beats ~3 billion times
49
How many primary branches does the left coronary artery have?
the left coronary artery has two primary branches
50
What is the function of the anterior interventricular artery?
the anterior interventricular artery supplies the anterior walls of the right/ left ventricles with blood vessels
51
What is another term for the left anterior interventricular artery and why?
the left anterior interventricular artery is also known as the "widow maker" because it is the primary causation of myocardial infarctions (heart attacks)
52
What is the function of the circumflex artery?
the circumflex artery is responsible for supplying the left atrium and posterior wall of the left ventricle with blood
53
What side of the heart does the circumflex artery pass over?
the circumflex artery passes over the left side of the heart
54
How many primary branches does the right coronary artery have?
the right coronary artery is made up of two primary branches
55
What two vessels make up the primary branches of the left coronary artery?
the two vessels that make up the primary branches of the left coronary artery are the anterior interventricular artery and the circumflex artery
56
What two vessels make up the primary branches of the right coronary artery?
the two vessels that make up the primary branches of the right coronary artery are the right marginal artery and the posterior interventricular artery
57
What is the function of the right marginal artery?
the right marginal artery is responsible for supplying the right atrium and right ventricle with blood
58
Which side of the heart does the right marginal artery pass over?
the right marginal artery runs toward the apex of the heart but originates on the hearts lateral side; located anteriorly
59
What is the function of the posterior interventricular artery?
the posterior interventricular artery is responsible for supplying the posterior walls of the ventricle with blood
60
Which side of the heart does the posterior interventricular artery of the heart run towards?
the posterior interventricular artery runs toward the apex of the heart
61
Which two coronary vessels form an anastomosis on the posterior portion of the heart?
the two coronary vessels that form an anastomosis of the posterior end of the heart are the posterior interventricular artery and the anterior interventricular artery
62
What is a myocardial infarction?
a myocardial infarction is the sudden death of heart tissue
63
What is the cause of a myocardial infarction?
myocardial infarctions are a result of the sudden closing of a coronary blood vessel causing lack of blood flow
64
What is the clinical condition: angina pectoris
angina pectoris is a reversible sense of heaviness or chest pain
65
When is angina pectoris most often experienced?
angina pectoris is often experiences during and episode of myocardial ischemia
66
What is myocardial ischemia?
myocardial ischemia is a lack of blood flow in the heart
67
What does is mean for something to be hypoxic?
to be hypoxic means it is lacking oxygen
68
What is an anastomosis?
an anastomosis is a connection between two arteries
69
What is the function of an anastomosis?
an anastomosis is responsible for creating an alternative pathway for blood to flow to a certain area of the body
70
What percentage of the venous drainage enters the right ventricle?
20% of the venous drainage enters the right ventricle
71
What percentage of the venous drainage returns to the right atrium by way of the coronary sinus?
80% of the venous drainage returns to the right atrium by way of the coronary sinus
72
What are the characteristics of cardiac muscle?
characteristics of cardiac muscle consist of it being short, thick with one nucleus; it also has actin-myosin and t-tubules with cations
73
What are intercalated disks?
intercalated disks are thick connections that connect the myocytes end-to-end
74
What is happens to the cardiac cells if an individual cell becomes active?
if one cardiac cell becomes active the rest become active as well
75
What is the function of electrical gap junctions?
electrical gap junctions form channels that allow ions to move from cell to cell
76
Why is the electrical gap junction so important within the cardiac muscle (heart)?
the electrical gap junction allow one cell to stimulate its neighbors so that the entire myocardium acts as though it were a single cell
77
What sort of energy does the heart need in order to contract?
the heart depends almost exclusively on aerobic regulation to produce ATP
78
True or False: the heart is unable to be fatigued
true; a healthy heart does not fatigue
79
What is aerobic respiration?
aerobic respiration is the process of using oxygen to fuel something
80
What is anaerobic respiration?
anaerobic respiration is the process of not using oxygen to fuel something
81
What are the characteristics of the hearts metabolism?
the heart contains myoglobin stores, glycogen, mitochondria, and fatty acids
82
What is the function of myoglobin in the heart?
the myoglobin within the heart is responsible for storing oxygen
83
What is the function of the glycogen in the heart?
the glycogen within the heart is responsible for storing carbohydrates
84
What is the function of the mitochondria within the heart?
the mitochondria fill ~25% of the cardiac cells and are responsible for creating power
85
What is the function of the fatty acids within the heart?
the fatty acids within the heart are responsible for providing another method of fuel to the heart
86
What does the term "myogenic" mean?
the terms "myogenic" means that the heartbeat originates within the heart
87
What does the term "autorhythmic" mean?
the term "autorhythmic" suggests that something produces regular but spontaneous acts of depolarization
88
What is the function of the sinoatrial (sa) node?
the sinoatrial node is responsible for initiating the heartbeat and setting the hearts rate; the pacemaker
89
Where is the sinoatrial node located?
the sinoatrial node is located in the right atrium
90
What is the function of the atrioventricular (av) node?
the atrioventricular node is a second (and slightly slower) method of depolarization; relative to the sinoatrial node
91
What is the function of the atrioventricular (av) bundle/ bundle of his?
the atrioventricular bundle/ bundle of his is responsible for being a pathway for electrical signals from the atrioventricular node
91
Where is the sinoatrial node located?
the sinoatrial ode is located in the interatrial septum
92
What are the right/left bundle branches?
the right/ left bundle branches are divisions of the atrioventricular bundle that enter the interventricular septum and descend to the heart apex
93
What are the purkinje fibers?
the purkinje fibers are fibers that extend upward from the apex and spread throughout the ventricles
94
What is a cardiac rhythm?
a cardiac rhythm is the repeating pattern of contraction and relaxation of the heart
94
What happens to the heart is its systolic phase?
in the systolic phase of the heart, the heart contracts
95
what happens in the diastolic phase of the heart?
in the diastolic phase of the heart. the heart relaxes
96
When does atrial contraction occur?
atrial contraction (systole) occurs during ventricular relaxation (diastole); visa versa
97
How long does it take the ventricles to contract after the atriums have contracted?
after the atriums have contracted, it takes ~0.1s for the ventricles to contract
98
What controls the sinus rhythm?
the sinus rhythm is controlled by the sinoatrial node
99
What is the average heartbeat of an adult at rest?
the heart of and adult at rest typically beats ~70-80 beats/mm
100
What is heart arrhytmia?
heart arrhythmia is abnormal cardiac rhythm
101
What is the common causation of arrhythmia (heart block)?
the failure if any part of the heart conduction system to transmit signals is usually the result of disease
102
Describe the resting membrane potential of the heart.
the resting membrane potential of the heart is not stable and begins at ~60mV while slowly depolarizing due to a slow influx of na+
103
What is the "pacemaker potential" of the cardiac muscle?
the "pacemaker potential" is the slow depolarization of the hearts resting membrane potential
104
When does cardiac action potential occur?
cardiac action potential occurs at a threshold of ~-40mV
105
Which ion channels open during cardiac depolarization?
during cardiac depolarization, voltage-gated ca+ channels open; ca+ flows in
106
Which ion channels open during cardiac repolarization?
during cardiac repolarization, k+ channels open; k+ flows out
107
What is the threshold that needs to be reached before cardiac depolarization starts over again?
at -60mV k+ channels close and the cardiac depolarization cycle starts again
108
Describe the process of impulse conduction to the myocardium.
the sinoatrial node travels quickly through the atria where the atrioventricular node slows the signal down and allows the ventricles to fill with blood; afterwards the atrioventricular bundle and purkinje fibers move the signal along the ventricles
109
Why is it important that ventricular contraction is initiated at the beginning of the apex and spreads upwards?
it's important that ventricular contraction starts at the apex because the blood needs to pushed upwards/ outwards into the pulmonary trunk and aorta
110
What are monocytes?
monocytes are the contractile cells of the myocardium
111
what is the resting membrane potential of monocytes?
monocytes have a stable resting membrane potential of ~-90mV
112
What causes the "plateau" of the myocardial contractions to occur?
the "plateau" is caused by Ca2+ voltage-gated channels; prolongs the contraction
113
What causes depolarization of the myocardium?
depolarization of the is caused by voltage-gated na+ channels
114
What causes the repolarization of the myocardium to occur?
repolarization of the myocardium occurs when ca+2 channels close and voltage-gated k+ channels open; the cell returns to resting membrane potential
115
What is an electrocardiogram (ecg/ ekg)?
an electrocardiogram is the recording of electrical changes that occur in the myocardium during a cardiac cycle
116
What does the p-wave on an electrocardiogram reflect?
the p-wave reflects the depolarization of the atria
117
What does the qrs-complex on an electrocardiogram reflect?
the qrs-complex reflects the depolarization of the ventricles
118
What does the t-wave on an electrocardiogram reflect?
the t-wave reflect the repolarization of the ventricles
119
Which part of the cardiac cycle is not reflected on an electrcardiogram?
atrial repolarization occurs but is not reflected on an electrocardiogram
120
What does an abnormal electrocardiogram suggest?
an abnormal electrocardiogram suggests that there are electrical conduction problems and approaching myocardial infarction (heart attack)
121
Describe the cardiac cycle.
the cardiac cycle consists of one complete contraction and the relaxation of all four chambers of the heart
122
When does atrial contraction of the cardiac cycle occur (in relation to the ventricles)?
atrial contraction occurs while the ventricles are relaxed
123
When does ventricular contraction of the cardiac cycle occur (in relation to the atriums)?
ventricular contraction occurs while the atria are relaxed
124
What is the quiescent period of the cardiac cycle?
the quiescent period of the cardiac cycle occurs when all chambers are relaxed/ inactive
125
Describe the cardiovascular system in reference to the vessels and their relationship to the heart.
the cardiovascular system is plumbing network of vessels (arteries and veins) with a motor (the heart) circulating the blood
126
Describe the process the heart needs to undergo in order to eject blood.
to eject blood the right/ left ventricles need to generate a pressure that is greater than the pressure within the major arteries
127
What sound does the heart make when it beats?
the heart makes a "lubb-dubb" sound when it beats
128
what is the "lubb" sound the heart makes indicative of?
the "lubb" sound indicates that the atrioventricular valves are closing
129
what is the "dubb" sound the heart makes indicative of?
the "dubb" sound indicates the closing of the semilunar valves
130
What is the first phase of the cardiac cycle?
the first phase of the cardiac cycle is the quiescent period
131
What is the second phase of the cardiac cycle?
the second phase of the cardiac cycle is atrial systole
132
What occurs during the quiescent period of the cardiac cycle?
during the quiescent period all chambers are relaxed and blood flows from the atria into the ventricles
133
What occurs during the atrial systole phase of the cardiac cycle?
the sinoatrial node fires and the atria depolarizes; the p-wave appears on the electrocardiograph while the atria contract and force additional blood into the ventricles
134
What is the end-diastolic volume (edv)?
the end-diastolic volume is the total amount of blood in ech ventricle after atrial systole - contraction; typically ~130ml
135
Describe the process of isovolumetric contraction in reference to the ventricles.
the atria repolarizes and relaxes followed by the depolarization of the ventricles,
afterwards the ventricles contract and the rising pressure causes the atrioventricular valves to close; blood has yet to be ejected
136
Describe the process of ventricular ejection.
rising pressure in the ventricles open the semilunar valves causing a rapid ejection of the blood leading to a reduced ejection as pressure drops
137
What is stroke volume (sv)?
stroke volume is the amount of blood ejected by each ventricle after contraction
138
What is the average stroke volume?
the average stroke volume is ~70mL at rest
139
What is an ejection fraction (ef)?
ejection fraction is the percentage of blood ejected by each ventricle
140
Describe the ejection fraction at rest, during exercise, and with a diseased heart.
the ejection fraction during rest is ~54%, during exercise it's ~90%, and in a diseased heart it is less than 50%
141
What is the end-systolic volume (esv)?
end-systolic volume is the amount of blood remaining in each ventricle following ventricular systole (contraction)
142
Describe the process of isovolumetric relaxation of the muscles.
ventricles repolarize and relax followed by the semilunar valves closing,
the atrioventricular valves remain closed and the ventricle expand but don't fill; the process starts over
143
What is cardiac output (q)?
cardiac output is the amount of blood ejected by each ventricle in one minute
144
What is the equation for cardiac output?
cardiac output = heart rate x stroke volume (the amount of blood pumped per beat)
145
What is the equation for finding the average resting cardiac output?
heart rate (75 beats/min) x stroke volume (70 ml/beats) = 5.0 L/min
146
What is the equation for finding the max exercise cardiac output?
heart rate (200 beats/min) x stroke volume (110 ml/beats) = 22 L/min
147
How is the heart rate measured?
the heart rate is measured from pulse
148
What is the average heart rate for infants?
the average heart rate for infants is less than 120 beats/min
149
What is the average heart rate for adults?
the average heart rate for adults is
60 - 80 beats/min
150
What does the term "tachycardia" suggest?
the term "tachycardia" suggests a persistent heart rate of more than 100 beats/ min
151
What are the likely causes of tachycardia?
likely causes of tachycardia are high levels of stress, anxiety, use of drugs, or disease
152
What dies the term "brachycardia" suggest?
the term "brachycardia" suggests a persistent heart rate of less than 60 beats/ min
153
What are likely causes of brachycardia?
likely causes of brachycardia are that the individual is sleeping or is an endurance athlete
154
How is the regulation of heart rate determined?
the regulation of heart rate is determined by the tissues need of oxygen
155
What does the term "intrinsic" indicate in reference to heart rate?
the term "intrinsic" in reference to heart rate indicates that the sinoatrial node sets the resting heart rate
156
What does the term "extrinsic" indicate in reference to heart rate?
the term "extrinsic" indicates that the autonomic nervous system can modify the heart rate
157
Where is the cardioacceleratory center housed?
the cardioacceleratory center is housed in the medulla oblongata
158
What is the first step of the cardioacceleratory center if it is trying to modify the heart rate?
the first step is that the sympathetic neurons from the cardiac plexus innervate the sinoatrial and atrioventricular nodes, myocardium, and coronary arteries
159
What is the second step of the cardioacceleratory center if it is trying to modify the heart rate?
the second step it that when stimulated the sympathetic neurons release norepinephrine that attaches to the beta-receptors and causes an increases heart rate and force of contraction
160
What are beta-blockers?
beta-blockers are drugs that prevent and increase in the heart rate by blocking beta-receptors on the heart cell
161
Where is the cardioinhibitory center located?
the cardioinhibitory center is housed in the medulla oblongata and arises from neurons in the medulla to make up the vagus nerve
162
What is the first step of the cardioinhibitory center if it's trying to modify the heart rate?
the parasympathetic neurons innervate the sinoatrial and atrioventricular nodes through the vagus nerve
163
What is the second step of the cardioinhibitory center if it's trying to modify the heart rate?
when the sinoatrial and atrioventricular nodes are stimulated, acetylcholine is released causing a decrease in activity for both nodes and slowing the heart rate
163
Why does the release of acetylcholine during cardio inhibition cause a decrease in activity?
the release of acetylcholine causes a decrease in activity because it moves the resting membrane potential further from the threshold/ hyperpolarizes it
163
What is the function of receptors in reference to the cardiovascular system?
receptors regularly send information to the higher brain center
163
What is the function of baroreceptors?
baroreceptors are responsible for sending continuous signals to the cardiac center of the brain
163
What are baroreceptors?
baroreceptors are pressure sensor in the aorta and carotid vessels
