Unit 14 - The Heart Flashcards
1
Q
The continual circulation of blood throughout the body is essential for maintaining _____
A
Homeostasis (a state of equilibrium within the body)
2
Q
In a healthy adult male, the heart beats about _____ per minute
A
75 times
3
Q
The amount of blood pumped from one ventricle per minutes is called the
A
Cardiac Output
4
Q
The heart can increase its output up to _______ when the body is more active, and the cells need oxygen and nutrients at a faster pace.
A
Five or six-fold
5
Q
The “cardiovascular system” consists of the _______
A
Heart and Blood Vessels
6
Q
There are two basic types of blood vessels, which are they
A
Arteries & Veins
7
Q
These carry blood away from the heart
A
Arteries
8
Q
These carry blood towards the heart
A
Veins
9
Q
The arteries branch to form smaller _____
A
Arterioles
10
Q
Most arteries carry blood high in ______
except for the pulmonary arteries
A
Oxygen
11
Q
The veins branch to form smaller _____
A
Venules
12
Q
Most veins carry blood low in _____
except for the pulmonary veins
A
Oxygen
13
Q
The arteries and veins entering and leaving the heart are called the ______, because of their relatively large diameter
A
Great Vessels
14
Q
The heart’s anatomy ensures the “______ flow” of blood through both the heart and blood vessels.
A
Unidirectional
15
Q
Backflow of blood is prevented by ______ within the heart
A
Valves
16
Q
The heart acts like two side-by-side pumps that work at the same rate, but with different amounts of force and pressure.
1) The ______ directs blood to the lungs for gas exchange.
2) The ______ directs blood to body tissues for nutrient and respiratory gas delivery
A
- Right Side
2. Left Side
17
Q
The heart develops “______” through alternate cycles of heart wall contraction and relaxation
A
blood pressure
18
Q
A minimum _______ is essential to push blood through blood vessels to the body tissues for nutrient and waste exchange
A
blood pressure
19
Q
The cardiovascular system consists of two circulations, which are they
A
Pulmonary and systemic circulations
20
Q
The “pulmonary circulation” consists of what
A
a. The chambers on the right side of the heart (right atrium and right ventricle)
b. “Pulmonary arteries”, which convey poorly oxygenated blood to the lungs to eliminate carbon dioxide and to replenish oxygen.
c. “Pulmonary veins”, which convey blood containing relatively low amounts of carbon dioxide and high amounts of oxygen from the lungs to the left side of the heart for pumping to the systemic circulation.
21
Q
Convey poorly oxygenated blood to the lungs to
eliminate carbon dioxide and to replenish oxygen.
A
Pulmonary Arteries
22
Q
convey blood containing relatively low amounts of carbon dioxide and high amounts of oxygen from the lungs to the left side of the heart for pumping to the systemic circulation.
A
Pulmonary Veins
23
Q
The “systemic circulation” consists of what
A
(a) The chambers on the left side of the heart (left atrium and left ventricle).
(b) All the other named blood vessels that carry blood to all the peripheral organs and tissues of the body.
- Blood that is high in oxygen (oxygenated) from the left side of the heart is
pumped into the “aorta”, the largest systemic artery in the body, and then into
smaller systemic arteries. - Gas exchange in tissues occurs from the body’s smallest vessels, called
“capillaries”. - Systemic veins carry blood that is low in oxygen (deoxygenated) and high in
carbon dioxide and waste products. - Most veins merge into the “superior vena cava” or into the “inferior vena cava”,
both of which drain blood into the right atrium.
24
Q
Blood that is high in oxygen (oxygenated) from the left side of the heart is pumped into the _____, the largest systemic artery in the body, and then into smaller systemic arteries.
A
Aorta
25
Gas exchange in tissues occurs from the body’s smallest vessels called ______
Capillaries
26
______ carry blood that is low in oxygen (deoxygenated) and high in carbon dioxide and waste products
Systemic Veins
27
Most veins merge into the _______, both of which drain blood into the right atrium.
“superior vena cava” or into the “inferior vena cava”
28
Where is the heart located?
The heart is located in the mediastinum left of the body midline and posterior to the sternum.
29
The heart is rotated such that its _________
is located more anteriorly, while its ________
is located more posteriorly
right side or border (right atrium and right ventricle)
left side or border (left atrium and left ventricle)
30
The posteriosuperior surface of the heart, formed primarily by the left atrium, is called the ____
“base”
31
What borders the base?
The pulmonary veins that enter the left atrium
32
The inferior, conical end of the heart is called the ______ and it projects slightly anterioinferiorly toward the left side of the body
“apex”
33
The heart is contained within the ______,
| a fibrous sac and double-layered serous lining.
“pericardium”
34
The _______ restricts heart movements so that it doesn’t bounce and move about in the thoracic cavity, and prevents the heart from overfilling with blood.
“pericardium”
35
The pericardium is composed of two parts, what are they
Fibrous Pericardium & Serous Pericardium
36
The outer portion of the pericardium is a tough, dense connective tissue layer
Fibrous Pericardium
37
This layer is attached to both the diaphragm and the base of the great vessels.
Fibrous Pericardium
38
The inner portion of the pericardium is a thin, double-layered serous membrane
Serous Pericardium
39
The serous pericardium may be subdivided into two layers that are actually continuous with each other and reflect along and attach to the great vessels
Parietal Layer & Visceral Layer
40
The _____ of this serous membrane lines the inner surface of the fibrous pericardium.
“parietal layer”
41
The ______ of this serous membrane is fused to the outer surface of the heart
“visceral layer”
42
The visceral layer is also called the _____
Epicardium
43
The thin potential space between the parietal and visceral layers of the serous pericardium is called the ________
“pericardial cavity”
44
______ is secreted into the pericardial cavity in order to lubricate the membranes and facilitate the almost frictionless continuous movement of the heart when it beats.
Serous Fluid
45
Inflammation or bleeding into the pericardial cavity can lead to ______
“cardiac tamponade”
This life-threatening condition is characterized by “pulsus paradoxus”, “jugular vein distention” (JVD), and falling blood pressure
46
an inflammation of the pericardium, typically caused by viruses, bacteria, or fungi
Pericarditis
47
Pericarditis inflammation is associated with an increase in ______ of the capillaries, which become more “leaky,” resulting in fluid accumulation in the pericardial cavity
permeability
48
The heart is unable to pump blood, leading to a medical emergency called _______ and possibly resulting in heart failure and death
cardiac tamponade
49
A helpful physical finding in diagnosing pericarditis is _______, a crackling or scraping sound heard with a stethoscope that is caused by the movement of the inflamed pericardial layers against each other.
friction rub
50
The heart is a relatively small, conical organ approximately the size of a person’s _______
Clenched Fist
51
The heart wall consists of three distinctive layers, what are they
Epicardium, Myocardium, Endocardium
52
the outermost heart layer and is also
| known as the visceral layer of the serous pericardium
Epicardium
53
the middle layer of the heart wall and is composed of cardiac muscle tissue
Myocardium
54
the thickest of the three heart wall layers
Myocardium
55
where “myocardial infarctions” (MIs or heart attacks)
| occur.
Myocardium
56
The internal surface of the heart and the external surfaces of the heart valves are covered by ______
Endocardium
57
The endocardium is contiguous with the “________, the inner lining of the blood
vessels
endothelium
58
The heart is composed of four hollow chambers, what are they
1) Two smaller atria
| 2) Two larger ventricles
59
Are thin-walled chambers that are located superiorly
Atria
60
The anterior part of each atrium is a wrinkled, flap-like extension called an ______
Auricle
61
The atria receive blood returning to the heart through both circuits.
(a) The ____ atrium receives blood from the systemic circuit.
(b) The _____ atrium receives blood from the pulmonary circuit
Right
Left
62
Blood that enters an atrium is passed to the ventricle on the _____ side of the heart.
Same
63
the inferior chambers of the heart
Ventricles
64
Two large arteries exit the heart at the basal surface, what are they
The pulmonary trunk and aorta
65
carries blood from the right ventricle into the
| pulmonary circuit
The pulmonary trunk
66
conducts blood from the left ventricle into the systemic circuit
Aorta
67
The valves, which are lined with _______, allow blood to only travel in one direction and prevent backflow.
endothelium
68
Is located between the atria and the ventricles, and is
| formed from dense irregular connective tissue.
The “fibrous skeleton”
69
The fibrous skeleton performs several important functions, what are they
(a) Separates the atria and ventricles.
(b) Anchors heart valves by forming supportive rings at their attachment points.
(c) Provides electrical insulation between atria and ventricles.
- This insulation ensures that the muscle impulses are NOT spread randomly
throughout the heart, and thus prevents all of the heart chambers from beating at
the same time.
(d) Provides a rigid framework for the attachment of cardiac muscle tissue.
70
The “right atrium” receives venous blood from the ______ and from the heart muscle itself
systemic circulation
71
The ______ drains blood from the head, neck, upper limbs, and the superior regions of the trunk.
superior vena cava
72
The ______ drains blood from the lower limbs and trunk.
“inferior vena cava”
73
The ______ drains blood from the heart wall.
“coronary sinus”
74
The ______ forms a thin wall between the right and left atria.
“interatrial septum”
75
There is an oval depression in the interatrial septum called the _______
“fossa ovalis”
76
occupies the former location of the “foramen ovale” which shunted blood from the right atrium to the left atrium during fetal life
“fossa ovalis”
77
Separating the right atrium form the right ventricle is the _______
“right atrioventricular (AV) valve” (also called the “tricuspid valve”, since it has three triangular flaps)
78
Deoxygenated venous blood flows from the right atrium, through the _____, into the right ventricle.
right AV valve
79
The right AV valve is forced closed when the _____ begins to contract, preventing backflow into the right atrium.
right ventricle
80
The _______ receives deoxygenated venous blood from the right atrium
“right ventricle”
81
An ______ forms a thick wall between the right and left ventricles
“interventricular septum”
82
The internal wall surface of each ventricle displays characteristic large, smooth, irregular muscular ridges, called the _______
“trabeculae carneae”
83
The _____ has three cone-shaped, muscular projections, called “papillary muscles”, which anchor thin strands of collagen fibers called “chordae tendineae”.
Right Ventricle
84
The right ventricle has three cone-shaped, muscular projections, called _____
“papillary muscles”
85
The Papillary muscles anchor thin strands of collagen fibers called ______
“chordae tendineae”
86
Chordae tendineae attach to the lower surface of cusps of the _______ and prevent the valve from everting and flipping into the atrium when the right ventricle is contracting.
right AV valve
87
At the superior end of the right ventricle is the ______, which marks the end of the right ventricle and the entrance into the pulmonary
trunk.
“pulmonary semilunar valve”
88
The pulmonary trunk divides shortly into right and left ________, which carry deoxygenated blood to the lungs
“pulmonary arteries”
89
______ are located within the walls of both ventricles immediately before connection of the ventricle to the pulmonary trunk and aorta.
Semilunar valves
90
Each semilunar valve is composed of three thin, half-moon-shaped, pocket-like ________
Semilunar cusps
As blood is pumped into the arterial trunks, it pushes against the cusps, forcing the valves open
91
Once gas exchange occurs in the lungs, the oxygenated blood (such blood is typically red) travels through the _____ to the left atrium.
pulmonary veins
92
The smooth posterior wall of the left atrium contains openings for approximately ____ pulmonary veins.
- Sometimes two of these vessels fuse prior to reaching the left atrium, thus
decreasing the number of openings through the atrial wall.
Four
93
Separating the left atrium from the left ventricle is the ______
“left atrioventricular (AV) valve” (also called the “bicuspid valve”, since it has two triangular cusps, or it may be called the “mitral valve”, since the two triangular cusps resemble a miter, the headpiece worn by a bishop).
94
Oxygenated blood flows from the left atrium, through the ______, into the left ventricle.
left AV valve
95
The ______ is forced closed when the left ventricle begins to contract, preventing blood backflow into the left atrium
left AV valve
96
The left ventricle has a wall that is typically three times thicker than the right ventricular wall
True
97
The left ventricle requires thick walls in order to generate enough pressure to force the oxygenated blood that has returned to the heart from the lungs into the aorta and then through the entire systemic circulation
True
98
The trabeculae carneae in the left ventricle are more prominent than those in the right ventricle.
True
99
Two large papillary muscles project from the ventricle’s inner wall and attach to the ____ that help support the left AV valve.
chordae tendineae
100
At the superior end of the ventricular cavity, the ______” marks the end of the left ventricle and the entrance to the aorta
“aortic semilunar valve
101
The “lubb” sound is also known as the S1 sound and represents _____
the closing of the atrioventricular valves
102
The “dupp” sound is also known as the S2 sound and is _____
the closing of the semilunar valves
103
An abnormal heart sound, generally called a ______, is the first indication of heart valve problems
heart murmur
104
■The aortic semilunar valve is best heard in the second intercostal space to the right of the sternum.
■The pulmonary semilunar valve is best heard in the second intercostal space to the left of the sternum.
■The right AV valve is best heard at the inferior left sternal border in the fifth intercostal space.
■The left AV valve is best heard near the apex of the heart (at the level of the left fifth intercostal space, about 9 centimeters from the midline of the sternum).
Yes, true
105
A heart murmur is usually the result of turbulence of the blood as it passes through the heart, and may be caused by what
valvular leakage, decreased valve flexibility, or a misshapen valve
106
Two types of heart murmurs
valvular insufficiency and valvular stenosis
107
Also termed valvular incompetence, occurs when one or more of the cardiac valves leaks because the valve cusps do not close tightly enough
Valvular insufficiency
108
is scarring of the valve cusps so that they become rigid or partially fused and cannot completely open
Often the affected chamber undergoes hypertrophy and dilates
Valvular stenosis
109
A primary cause of valvular stenosis is _____, which may follow a streptococcal infection of the throat
rheumatic heart disease
110
________ travel in the atrioventricular groove between the atria and ventricles to supply the heart wall.
“Left and right coronary arteries”
111
These arteries are the only branches of the ascending aorta.
“Left and right coronary arteries”
112
They exit the ascending aorta immediately superior to the aortic semilunar valve.
“Left and right coronary arteries”
113
The left and right coronary arteries branch into smaller arteries and arterioles to deliver oxygenated blood and nutrients ________ of the atria and ventricles.
to the capillaries of the myocardium
114
Coronary arteries may become narrowed and occluded with plaques in a condition called _____
atherosclerosis or coronary artery disease
115
sudden narrowing of the vessels caused by smooth muscle contraction in their wall
coronary spasm
116
Either atherosclerosis or coronary spasm can lead to ______ or the more severe myocardial infarction.
angina pectoris
117
a poorly localized pain sensation in the left side of the chest, the left arm and shoulder, or sometimes the jaw and the back
angina pectoris
it results from strenuous activity, when workload demands on the heart exceed the ability of the narrowed coronary vessels to supply blood
118
The term _____ refers to death of tissue due to lack of blood supply.
infarction
119
commonly called a heart attack, is a potentially lethal condition resulting from sudden and complete occlusion of a coronary artery.
Myocardial infarction (MI)
120
is characterized by inadequate supply of
| oxygen and blood to a part of the body
“Ischemia”
“Myocardial ischemia” can be painless (silent myocardial ischemia) or agonizing
(angina pectoris).
121
Venous return occurs through one of several ____ that collect deoxygenated blood and wastes from the myocardial capillaries.
“cardiac veins”
122
All of cardiac veins drain into the _______, a large vein that lies in the posterior aspect of the atrioventricular groove.
“coronary sinus”
123
Because the ventricular myocardium is compressed during contraction (systole), most coronary flow occurs during _____, when ventricular walls are relaxed.
relaxation (diastole)
124
a. Normally, flow is evenly distributed throughout the thickness of the myocardium.
b. Under certain circumstances, however, coronary flow may be reduced, especially to the regions immediately external to the endocardium.
True
125
an abnormally increased heart rate
(greater than 100 beats per minute), shortens diastole and reduces blood flow to
the ventricular myocardium.
“Tachycardia”
126
____, abnormally low blood pressure, can also reduce the ability of
blood to flow through the ventricular myocardium.
“Hypotension”
127
contractions are made possible by the properties of cardiac muscle tissue and by specialized cells in the heart, known collectively as its
conducting system
128
```
The heart exhibits _______, meaning that the
heart itself (not external nerves) is responsible for initiating the heartbeat.
```
“autorhythmicity” or “intrinsic rhythmicity”
129
The heartbeat is initiated by the cardiac fibers of the ______, which are located in the posterior wall of the right atrium, adjacent to the entrance of the superior vena cava
“sinoatrial (SA) node”
130
The fibers of the _____ act as the “pacemaker”, the rhythmic center that establishes the pace for cardiac activity
SA node
131
Under the influence of the parasympathetic innervation, SA node fibers initiate impulses _____ times per minute
70-80
132
From the SA node the muscle impulses travel through cardiac muscle of both atria to cause contraction (atrial systole) and then to the _______”
“atrioventricular (AV) node"
133
The AV node is located where
in the floor of the right atrium between the right AV valve and the coronary sinus
134
the ______ insulates the atria from the ventricles to prevent random nerve impulses from spreading between the atria and the ventricles.
fibrous skeleton
135
Thus, it is only through an opening in the fibrous skeleton that the muscle impulse can spread. This bundle is the atrioventricular bundle or the _____
“Bundle of His”.
136
The muscle impulse then travels from the AV node to the ___________
“atrioventricular (AV) bundle”, also called the “Bundle of His”.
This bundle of conducting muscle fibers extends into the interventricular septum and then divides into one right bundle branch and two left bundle branches
137
These bundle branches conduct the impulse to conduction fibers called ______ that begin within the apex of the heart and extend through the walls of the ventricles.
“Purkinje fibers”
Purkinje fibers are larger than other cardiac muscle fibers.
Muscle impulse conduction along the Purkinje fibers is extremely rapid, consistent with the large size of the cells, and the impulse spreads immediately throughout the ventricular myocardium, stimulating it to contract.
138
The electrical activity of this conduction system, or more correctly, its effects on the myocardium, can be monitored with an __________
“electrocardiograph”, which generates an
| “electrocardiogram” (ECG or EKG).
139
The heart is innervated by the ______ nervous system
autonomic
140
innervation of the heart consists of both sympathetic and parasympathetic components, collectively referred to as the _______
“coronary plexus”
The autonomic centers in the brainstem
don’t initiate a heartbeat, but they can increase or decrease the heartbeat
141
“Sympathetic innervation” of the heart is carried out by nerve fibers from the ______ segments of
the spinal cord.
T1-T5
142
Sympathetic innervation _____ the rate and force of heart contractions
increases
143
“Parasympathetic innervation” comes from the ______
medulla oblongata via the left and right vagus nerves (CN X).
As the vagus nerves descend into the thoracic cavity they give off branches that supply the heart.
144
Parasympathetic innervation ______ heart rate, but generally tends to have no effect on the force of contractions.
decreases
145
the inclusive period of time from the start of one heartbeat to the initiation of the next.
A “cardiac cycle”
146
The contraction of a heart chamber is called “_____”.
“systole”
During this period the contraction of the myocardium forces blood either into another chamber (from atrium to ventricle) or into a blood vessel (from a ventricle into the
attached larger artery).
147
The relaxation phase of a heart chamber is termed _____
“diastole”.
During this period the myocardium of each chamber relaxes between contraction phases and the chamber fills with blood.
148
At the beginning of the cardiac cycle _______ contract simultaneously.
the left and right atria
149
When the atria contract (atrial systole) blood is forced into the ventricles through the ______
open AV valves.
During this time blood is still returning to the right atrium from the superior vena cava, the inferior vena cava, and the coronary sinus and to the left atrium from the pulmonary veins.
150
After the atria begin to relax (atrial diastole), contraction of the ______ occurs simultaneously. Thus, only two of the four chambers (either atria or ventricles) contract at any one time.
left and right ventricles
151
When the ventricles contract, the _______ close as blood is pushed against the cusps of the AV valves and their edges meet to form a seal.
atrioventricular valves
Papillary muscles and the chordae tendineae prevent these valve leaflets from everting.
The semilunar valves are forced open and blood enters the pulmonary trunk and the aorta
152
When the ventricles are relaxing during the cardiac cycle (ventricular diastole) most of the blood flows passively from the relaxing atria into the ventricles through _______
open AV valves.
153
For the last one-half of the cardiac cycle all four chambers of the heart are in _____ together
diastole
154
any abnormality in the rate, regularity, or sequence of the cardiac cycle
Cardiac arrhythmia (also called dysrhythmia)
155
occurs when the atria beat at 200 to 400 times per minute. Abnormal muscle impulses flow continuously through the atrial conduction system, thus stimulating the atrial musculature and AV node over and over.
Atrial flutter
156
differs from atrial flutter in that the muscle impulses are significantly more chaotic, leading to an irregular heart rate. The ventricles respond by increasing and decreasing contraction activities, which may lead to serious disturbances in the cardiac rhythm.
Atrial fibrillation
157
often result from stress, stimulants such as caffeine, or sleep deprivation. They occur either singly or in rapid bursts due to abnormal impulses initiated within the AV node or the ventricular conduction system
Premature ventricular contractions (PVCs)
Most PVCs go unnoticed, although occasionally one is perceived as the heart “skipping a beat” and then “jumping” in the chest.
158
a disorganized, rapid, repetitious movement of the ventricular muscle that replaces normal contraction.
Ventricular fibrillation
159
This cessation of cardiac activity is called
Cardiac Arrest
160
can be used to continue the circulation of blood during cardiac arrest
Cardiopulmonary resuscitation (CPR)
161
Attempts to resynchronize cardiac muscle cell electrical activity require use of an
automated external defibrillator (AED) or paddle electrodes
162
an atypically slow heartbeat of less than 50
| beats per minute.
“Bradycardia”
163
a beneficial adaptation resulting from a muscular heart,
| healthy circulatory system, and excellent lung capacity.
“Athlete’s bradycardia”
164
during embryonic development, blood is shunted from the right atrium to the left atrium by traveling through the ________ and pushing a flap of tissue to the left called the _________
foramen ovale, “septum primum”.
165
In embryonic heart development, blood cannot flow back from the left atrium to the right because the _____ acts like a one-way flutter valve.
septum primum
166
When a baby is born and the lungs are fully functional, the blood from the left atrium pushes the septum primum closed, creating a closed interatrial septum
True
167
The only remnant of the embryonic opening (septum primum) is an oval-shaped depression in the interatrial septum called the ______
“fossa ovalis”.
168
Occasionally, the fossa ovalis may fail to close properly (“patent foramen ovale”, “perforated fossa ovalis”, or “atrial septal defect”) allowing blood to flow from the
right atrium to the left atrium, or vice versa.
True
169
Such an atrial septal defect (which can occur in up to _________ of the adult population) can lead to poor pulmonary circulation or allow blood clots and undesired materials to travel directly from the venous circulation into the arterial circulation.
30%
