Quiz 3 Flashcards
(147 cards)
1
Q
Right v Left Heart Fxn
A
2
Q
Vessels
types & fxn
A
Arteries:
Carry blood away from the heart
Capillaries:
Exchange fluids between the blood and interstitial space
Veins:
Carry blood to the heart
3
Q
Circulatory System
blood path
A
4
Q
Area where the heart is located
A
Mediastinum
5
Q
Mediastinum
A
where the heart is located
above the diaphragm and between the lungs
6
Q
Heart wall
Layers
A
Epicardium: outer smooth layer
Myocardium: thickest layer of cardiac muscle
Endocardium: innermost layer
7
Q
Pericardium & its components
A
Double-walled membranous sac
Parietal: surface layer
Visceral: inner layer
8
Q
Pericardial cavity
A
Space between the parietal and visceral layers
Contains pericardial fluid (20 mL)
9
Q
amount of pericardial fluid in the pericardial cavity?
A
(20 mL)
10
Q
Heart Chambers
A
Right atrium
Left atrium
Right ventricle
Left ventricle
11
Q
Atria are separated by
A
the interatrial septum.
12
Q
Ventricles are separated by
A
the interventricular septum.
13
Q
Thickness of each chamber depends on
A
the pressure or resistance it must overcome to eject blood.
14
Q
Heart Valves
fxn
A
Ensure one way blood flow
15
Q
Atrioventricular valves (AVs)
A
One-way flow of blood from the atria to the ventricles
Tricuspid valve: three leaflets or cusps
Bicuspid (mitral) valve: two leaflets or cusps
“Tri before you Bi”
16
Q
Semilunar valves
A
One-way flow from the ventricles to either the pulmonary artery or to the aorta
Pulmonic semilunar valve
Aortic semilunar valve
17
Q
Atrial contraction vs. ventricle contraction
A
18
Q
Great Vessels
A
Superior & inferior venae cavae:
deoxygenated blood systemic circulation → right atrium
R & L pulmonary arteries:
unoxygenated blood from right heart → BOTH lungs
Branch into pulmonary capillaries
19
Q
Right and left pulmonary arteries
Branch into
A
pulmonary capillaries
20
Q
Carry oxygenated blood from the lungs to the left side of the heart
A
Pulmonary veins
21
Q
Delivers oxygenated blood to systemic vessels that supply the body
A
Aorta
22
Q
Cardiac cycle
consists of…
makes up…
A
One contraction and one relaxation
one heartbeat
23
Q
Relaxation: ventricles fill
A) systole
B) diastole
A
Diastole
24
Q
blood leaves the ventricles during…
A
Systole
(Contraction)
25
Atrial systole and ventricle systole
26
Phases of the cardiac cycle
Phase 1: atrial systole or ventricular diastole
Phase 2: isovolumetric ventricular systole
Phase 3: ventricular ejection (semilunar valves open)
Phase 4: isovolumetric ventricular relaxation (aortic valve closes)
Phase 5: passive ventricular filling (mitral and tricuspid valves open)
27
Unoxygenated (venous) blood from systemic circulation enters the right atrium through
the superior and inferior venae cavae
28
From the atrium, the blood passes through the ____ valve into the right ventricle
right AV (tricuspid)
tRicuspid is on the Right
"tri before you bi"
29
blood flow once it enters right ventricle
inflow tract
outflow tract
pulmonic semilunar valve (pulmonary valve)
pulmonary artery
lungs
30
How many pulmonary veins are there?
Oxygenated blood:
lungs → left atrium
via 4 pulmonary veins
(two from left lung & two from right)
31
From the left atrium, the blood passes through the ____ into the left ventricle
left AV valve/mitral valve/bicuspid
32
Normal Intracardiac Pressures
(waves & what they represent)
A wave: Atrial contraction
V wave: Filling of the atrium from the peripheral veins
C wave: Bulging of the mitral valve into the left atrium
X descent: Ejection of blood from both ventricles
Y descent: Flow of blood into the right ventricle
33
Supplies oxygen and other nutrients to the myocardium
Coronary circulation
34
Right coronary artery
branches
Conus artery
Right marginal branch
Posterior descending branch
35
Left coronary artery
branches
Left anterior descending artery
Circumflex artery
36
Collateral arteries
connections/anastomoses between the branches of the coronary circulation
Protects the heart from ischemia
37
connections, or anastomoses, between the branches of the coronary circulation
Collateral arteries
38
Collateral arteries
Are formed by
arteriogenesis or angiogenesis
39
The Coronary veins
Coronary sinus
Great cardiac vein
Posterior vein of the left ventricle
40
Oxygenated blood enters the coronary arteries through
openings in the semilunar valves at the entrance to the aorta.
41
Deoxygenated blood from the coronary veins enters the right atrium through the
coronary sinus.
42
Coronary lymphatic vessels
fxn
drain fluid to the paratracheal lymph nodes.
43
Transmission of electrical impulses are called
Cardiac action potentials
44
Conduction system
Sinoatrial (SA) node
Atrioventricular (AV) node
Bundle of His (AV bundle)
Right and left bundle branches
Purkinje fibers
Ventricular myocardium
45
Sinoatrial (SA) node
fxn (2)
Pacemaker of the heart
Intranodal pathways
46
Refractory period
Heart muscles cannot contract.
Ensures that diastole (relaxation) will occur
47
Completes the cardiac cycle
Refractory period
48
Inside of the cell becomes less negatively charged
Depolarization: activation
49
Sum of all cardiac action potentials
electrocardiogram (ECG)
50
51
EKG components and their meaning
P wave: atrial depolarization
PR interval: time from the onset of atrial activation to the onset of ventricular activation
QRS complex: sum of all ventricular depolarizations
ST interval: ventricular myocardium depolarized
QT interval: “electrical systole” of the ventricles
52
Which EEG component varies inversely with the heart rate?
QT interval
53
time from the onset of atrial activation to the onset of ventricular activation
PR interval
54
ventricular myocardium depolarized
ST interval
55
Automaticity
Property of generating spontaneous depolarization to threshold
56
Automatic cells
all heart cells capable of spontaneous depolarization
57
Regular generation of an action potential by the heart’s conduction system
Rhythmicity
58
depolarizes spontaneously 60–100 times per minute
SA node
59
Automaticity vs. Rhythmicity
60
The ______ nervous system influences the rate of impulse generation (firing), depolarization, and repolarization of the myocardium
Autonomic
61
Autonomic nervous system
influences on heart action
-rate of impulse generation (firing), depolarization, and repolarization
-strength of contraction
-changes in the heart and circulatory system faster than metabolic or humoral agents
62
Cardiac innervation
Sympathetic nerves:
Increases conductivity & contraction strength
Parasympathetic nerves:
Decreases conduction & contraction
63
Adernergic
Receptors in Heart
α- or β-adrenergic receptors
Norepinephrine or epinephrine
Acetylcholine
64
Stimulation of both the β1 and β2
↑ HR (chronotropy)
&
↑contractile force (inotropy)
65
negative vs positive chronotropy
Negative chronotropy: decreases heart rate
Positive chronotropy: increases heart rate
66
+ vs - chronotropy
Negative inotropy: decreases force of contraction
Positive inotropy: increases force of contraction
67
Overall β1 and β2 stimulation
Heart pumps more blood.
β2 stimulation increases coronary blood flow.
68
β3 receptors
↓ contractility (negative inotropic)
“safety mechanism” to prevent an overstimulation of the heart by the sympathetic nervous system
69
receptor that provides a “safety mechanism” to prevent SNS overstimulation of the heart
B3
(negative inotropic effect)
70
Myocardial cells
Nearly identical to
skeletal muscle cells
71
Specialized intercellular junctions
Intercalated disks
72
Myocardial cells
components
Intercalated disks
T tubules
Actin, myosin, and the troponin-tropomyosin complex
73
Actin, myosin, and the troponin-tropomyosin complex
includes...
Troponins T, I, and C
Titin
74
features that distinguish myocardial cells from skeletal cells
faster AP transmission (via intercalated disks)
make more ATP (lots of mitochondria)
transverse tubules: easier access to ions
all enable the myocardium to work constantly, which skeletal muscles are not required to do
75
T/F
Both myocardial cells and skeletal muscle cells work constantly.
False
myocardial cells do
76
Contraction occurs when the ___ shortens, causing ....
sarcomere
adjacent Z lines to move closer together.
77
Myocardial contraction
steps
sarcomere shortens
adjacent Z lines come closer together
A band width (thick myosin filaments) doesnt change
I band: narrows
increased overlap between the thick and thin filaments
78
Cross-bridge cycling
Attachment of actin to myosin at the cross bridge
Myosin head molecule undergoes a position change.
Causes thin filaments to slide past thick filaments (contraction).
79
Calcium
Is stored in which 2 locations?
tubule system and the sarcoplasmic reticulum
80
Calcium
when does it enter the myocardial cell?
from the interstitial fluid after electrical excitation, which increases membrane permeability to calcium
81
increases membrane permeability to calcium
electrical excitation
82
Calcium
Diffuses toward the myofibrils, where it binds with
troponin
83
Excitation contraction coupling
AP triggers the cycle
↓
cross-bridge activity & contraction
Requires calcium
Calcium–troponin complex facilitates the contraction process.
84
facilitates the contraction process
Calcium–troponin complex
85
what begins myocardial relaxation?
Troponin release of calcium
85
substances that facilitate relaxation
Calcium, troponin, and tropomyosin
86
volume of blood flowing through either the systemic or the pulmonary circuit
Cardiac output
87
CO equation
HRxSV
88
Normal adult cardiac output at rest
5 L/min
89
Ejection fraction
66% for women and 58% for men
stroke volume/end-diastolic volume
90
Is an indicator of ventricular function
Ejection fraction
91
Preload
determined by two primary factors
Amount of venous return to the ventricle
Blood left in the ventricle after systole or end-systolic volume
92
When preload exceeds physiologic range....
further muscle stretching causes a decline in cardiac output.
93
Aortic systolic pressure is a good index of afterload for the _______
left ventricle.
94
Total peripheral resistance (TPR)
represents (pre/after)load.
after
95
Frank-Starling law of the heart
volume of blood at end diastole
Myocardial stretch determines contraction force
More stretch = Increased force of contraction
96
the major way that the right and left ventricles maintain equal minute outputs, despite stroke (beat) output variation
Frank-Starling law of the heart
97
Laplace’s law
Contractile force depends on the chamber radius & wall thickness
Small w/ thick walls = increased contraction force.
In ventricular dilation, the force needed to maintain ventricular pressure lessens available contractile force.
98
Determinants of the force of contraction
myocardium stretching (changes in ventricular volume/preload)
nervous system input to ventricles
myocardial O2 supply
99
Inotropic agents
+ and -
Norepinephrine
Epinephrine
Ach (released from vagus nerve)
100
T/F
Hypoxia decreases contractility
True
101
Average heart rate in healthy adults
~70
102
controls resting heart rate
parasympathetic system
103
HR
Neural reflexes
Baroreceptor reflex: ↓BP = ↑HR & arterioles constrict
Bainbridge reflex: △HR from IV infusions
104
Stuff that affects CO
105
Systemic circulation that supplies the skin and the extremities
Peripheral vascular system
106
Structure of Blood Vessels
Tunica intima: Innermost or intimal layer
Tunica media: Middle or medial layer
Tunica externa (adventitia): Outermost or external layer
107
Vasculogenesis
Growth of vessels from **progenitor or stemlike cells** that originate in the bone marrow and other body tissues
108
Processes for growing new blood vessels
Angiogenesis
Arteriogenesis
Vasculogenesis
109
Arteriogenesis vs Angiogenesis
Arteriogenesis:
Branching from larger vessels (arterioles)
Angiogenesis:
Branching of small vessels (capillaries)
110
contain fewer elastic fibers and more muscle fibers; can contract (vasoconstriction) and relax (vasodilation).
Muscular arteries
111
Capillaries
Substances move through via... (4)
Junctions between endothelial cells
Fenestrations (oval windows or pores)
Vesicles moved by active transport
Diffusion
112
Endothelium roles
Transport
Coagulation & fibrinolysis
Immune system
Tissue growth & wound healing
Vasomotion: contraction and relaxation of vessels
113
do we have more arteries or veins?
veins
114
distance blood travels in a unit of time
velocity
115
T/F
Low hematocrit reduces the flow through the blood vessels.
False
High
116
Laminar vs Turbulent flow
117
Vascular compliance
The increase in volume a vessel is able to accommodate for a given increase in pressure.
118
the opposite of compliance
stiffness
119
Which is more compliant?
Veins
Arteries
Veins
120
Mean arterial pressure (MAP)
Is the average pressure in the arteries throughout the cardiac cycle
121
total peripheral resistance is primarily a function of ....
the diameter of the arterioles
122
Vessels arrangement and effect on resistance
series (greater resistance)
parallel (lesser resistance)
123
Baroreceptors
fxn
Reduce BP to normal by decreasing CO & PVR
Can also increase BP when needed
124
Arterial receptors: chemoreceptors
Are sensitive to oxygen, carbon dioxide, or pH
Regulate blood pressure
125
Antidiuretic hormone
Increases blood volume by reabsorption of water from tubular fluid in the distal tubule and the collecting duct of the nephron
126
Renin-angiotensin-aldosterone system
hormones & their fxn
Aldosterone: stimulates reabsorption of sodium, chloride, and water to increase blood volume and stimulate thirst
Angiotensin II: vasoconstrictor
127
Natriuretic peptides
Cause loss of sodium, chloride, and water through their effects on kidney function, decreasing blood volume
128
Adrenomedullin
Powerful vasodilatory activity
129
Nitric oxide, prostaglandins, endothelium-derived relaxing factor
affect BP how?
vasodilation
130
Venous pressure
Main determinants
venous volume
Compliance
131
Mechanisms that affect venous pressure
Skeletal muscle pump
Respiratory pump
132
Coronary perfusion pressure
difference between pressure in the aorta and pressure in the coronary vessels
133
Autoregulation
organs to regulate blood flow by altering the resistance in its arterioles
134
maintains optimal perfusion pressure, despite systolic effects, especially in the coronary arteries
Autonomic self regulation
135
Myoglobin (in heart muscle)
fxn
stores oxygen for use during the systolic phase
136
Autoregulation
Between __ and __ mmHg
60 -140
137
Lymphatic system
Both ducts drain into the
subclavian
138
Afferent vs efferent lymphatic vessels
Afferent vessels carry lymph to the nodes.
Efferent vessels carry lymph away from the nodes
139
Chest x-ray vs Echocardiogram
CXR:
size and contour of the heart and related structures
Echo:
most effective and widely used noninvasive modality for evaluating the structures of the heart
140
Stress testing
"exercise testing"
Elicits S/S of heart Dz & CAD that may not appear at rest
injection of a radiotracer
141
Computed tomography (CT)
evaluates coronary artery disease and myocardial ischemia during stress testing.
142
Magnetic resonance imaging (MRI)
anatomy and physiology of the great blood vessels and myocardium in three dimensions
143
Angiography
fluoroscopically visualizes the coronary arteries
144
most common cause of morbidity and mortality in older adults
Cardiovascular disease
145
Aging effects
Myocardial & vessel stiffening
Changes in neurogenic control over vascular tone
AFIB more common
↓ exercise capacity
LV hypertrophy & fibrosis
146
Arterial stiffening
Cross-linking of collagen
Increased collagen
Changes in elastin
Decreased baroreceptor activity
