Cardiovascular System Flashcards
1
Q
What body cavity is the heart located in?
A
thoracic cavity
2
Q
what are organs found in the thoracic cavity?
A
heart, lungs, trachea, esophagus
3
Q
what organs are found in the superior mediastinum?
A
trachea and esophagus
4
Q
what organ is found in the pleural cavity?
A
lungs
5
Q
what organ is found in the pericardial mediastinum?
A
heart
6
Q
where is the heart located in relation to the midsternal line?
A
2/3 on the left of midline
7
Q
what is the name of the serous membrane that surrounds the heart?
A
pericardium
8
Q
what are the two layers of the pericardium?
A
visceral and parietal pericardium
9
Q
what is the space between the inner and outer pericardium called?
A
pericardial cavity
10
Q
what is found in the pericardial cavity?
A
serous fluid
11
Q
where does the systemic circuit carry blood?
A
out and back to body
12
Q
where do systemic arteries carry blood?
A
away from the heart
13
Q
where do systemic veins carry blood?
A
towards the heart
14
Q
what is the function of the cardiac circuit (coronary circulation)
A
supply the heart itself with blood
15
Q
where do cardiac arteries branch from?
A
base of aorta
16
Q
where do cardiac veins bring blood to?
A
coronary sinus
17
Q
where does the coronary sinus drain blood into?
A
right atrium
18
Q
what is the function of the pulmonary circuit?
A
bring blood to and from the lungs
19
Q
are pulmonary arteries bringing blood to or away from the lungs?
A
to the lungs
20
Q
what is the state of blood in pulmonary arteries?
A
de-oxygenated
21
Q
are pulmonary veins brining blood to or away from the lungs?
A
away from the lungs, back to the heart
22
Q
what is the state of blood in pulmonary veins?
A
oxygenated
23
Q
what is the function of capillary beds in body tissue?
A
sites of gas exchange
24
Q
what are the three layers of the heart wall from outermost to inner?
A
epicardium, myocardium, endocardium
25
what is another name for the epicardium?
visceral pericardium
26
what is the muscular layer of the heart?
myocardium
27
what layer of the heart is the contracting layer and forms the atria and ventricles?
myocardium
28
what type of epithelium is the endocardium?
simple squamous
29
what does the endocardium do?
covers inner walls and heart valves
30
what is different about atrial and ventricular muscle contractions?
duration of contraction is longer, has a long absolute refractory period
31
what are pacemaker cells called?
auto rhythmic cells
32
what interconnects cardiac muscle cells (fibers)?
intercalated discs
33
what are three key components of intercalated discs?
gap junctions, desmosomes and fascia adherens
34
what is the function of desmosomes in intercalated discs?
hold fibers together and convey force of contraction
35
what is the function of gap junctions in intercalated discs?
propagate muscle action potentials between cells by allowing ions and chemical communication to pass
36
what is the function of fascia adherens in intercalated discs?
provides an anchor for myofibrillar proteins
37
what does cardiac muscle function as?
syncytium, heart muscle cells are interconnected
38
functional syncytium
cardiac cells are mechanically, electrically and chemically connected
39
does cardiac muscle tissue have triads?
no
40
what do intercalated discs allow?
action potential to move cell to cell
41
what does cardiac muscle rely on for getting Ca for muscle contraction? and why?
rely on extracellular Ca because SR in cardiac muscle lack large terminal cisternae
42
shape and size of t tubule in cardiac muscle?
short and broad and encircles the sarcomere at the Z-lines and not the zone of overlap
43
are mitochondria more abundant in cardiac or skeletal muscle?
cardiac muscle
44
what type of metabolism does cardiac muscle use?
aerobic
45
what type of metabolism does skeletal muscle use?
anaerobic
46
what has more myoglobin cardiac or skeletal muscle and why?
cardiac muscle because aerobic respiration
47
what substances are elevated in cardiac cells due to aerobic metabolism?
intracellular glycogen and lipid inclusions
48
what are the three branches of the aorta?
brachiocephalic artery, left common carotid and left subclavian
49
what are the four muscular chambers of the heart?
right atrium, right ventricle, left atrium, left ventricle
50
what is the right side of the heart called?
pulmonary pump
51
what is the left side of the heart called?
systemic pump
52
what does the right atrium do?
collects de-oxygenated blood from systemic circuit and coronary sinus
53
what does the right ventricle do?
pumps de-oxygenated blood to the pulmonary circuit via the pulmonary artery
54
what does the left atrium do?
collects oxygenated blood from the pulmonary circuit via the pulmonary veins
55
what does the left ventricle do?
pumps oxygenated blood to the systemic circuit
56
what structure separates the right and left ventricles?
interventricular septum
57
where does the superior vena cava receive blood from?
head, neck, upper limbs, and chest
58
where does the inferior vena cava receive blood from?
trunk, viscera, and lower limbs
59
before birth, what is the opening through the interatrial septum called?
foramen ovale
60
what does the foramen ovale become after birth?
fossa ovalis
61
what are raised bundles of cardiac muscle found in the ventricles called?
trabeculae carneae
62
where is the moderator band found and what is its function?
found in the right ventricle and is a muscular ridge that extends from the inter ventricular septum and connects to the anterior papillary muscle. It contains part of the conducting system and coordinates contractions of cardiac muscle cells.
63
true or false, both sides of the heart accept and pump equal amounts of blood?
true
64
function of atrioventricular valves?
prevent back flow of blood from ventricles to atria during systole?
65
what is the right AV valve called?
tricuspid valve
66
what is the left AV valve called?
bicuspid
67
chordae tendineae function?
connective tissue that anchor flaps to walls of ventricles to prevent AV valves from opening backwards
68
where do chordae tendineae originate?
papillary muscles
69
function of semi-lunar valves?
prevent back flow of blood from the aorta and pulmonary arteries into the ventricles during diastole
70
what are the two semi-lunar valves?
pulmonary and aortic semilunar valves
71
do semi-lunar valves have muscular support? what do they have instead?
no muscular support, have three cusps support like tripod
72
what does the pulmonary trunk divide into?
right and left pulmonary arteries
73
what does the ascending aorta turn into?
turns into aortic arch and then becomes descending aorta
74
systolic pressure
measures the peak pressure in arteries during contraction. The ventricles contract, ventricular pressure rises, AV valves close and semi-lunar valves open
75
diastolic pressure
measures the aortic pressure when the ventricles relax, AV valves open and semi-lunar valves close
76
normal blood pressure
< 120/80 mm Hg
77
elevated blood pressure
120-129/ <80 mm Hg
78
hypertension stage 1
130-139/ 80-89 mm Hg
79
hypertension stage 2
>= 140/ >= 90 mm Hg
80
hypertensive crisis
> 180/ >120
81
what's larger left or right ventricle?
left
82
what has thicker and more powerful muscles, left of right ventricle?
left
83
does the left ventricle have a moderator band?
no
84
what shape is the right ventricle and what shape is the left?
right ventricle is pouch-shaped and the left ventricle is round
85
what are the thee types of veins?
large, medium sized, and venule
86
what are the three types of arteries?
elastic, muscular, arteriole
87
what are the three layers of typical blood vessels?
tunica externa, tunica media, tunica intima
88
what is the tunica externa usually made out of?
elastic fibers and connective tissue
89
what is the tunica media usually made out of?
smooth muscular layer with elastic fibers
90
what is the tunica intima usually made out of?
basement membrane with a endothelium layer made out of simple squamous epithelia
91
what is the conducting artery?
elastic artery
92
what is the distribution artery?
muscular artery
93
what are the three types of capillaries?
continuous, fenestrated, sinusoid
94
general appearance difference between arteries and veins?
arteries are usually round with thick walls, veins are usually flattened or collapsed with thin walls
95
difference in tunica intima between veins and arteries?
tunica intima of arteries are rippled due to vessel constriction, tunica intima of veins are often smooth
96
difference in tunica media of veins and arteries?
arteries have thick tunica media dominated by smooth muscle cells and elastic fibers. veins have thin tunica media dominated by smooth muscles cells and collagen fibers
97
what differentiates elastic arteries?
high compliance, walls expand in response to pressure to accommodate surge of blood
98
what differentiates muscular arteries?
larger tunica media, more smooth muscle
99
continuous capillaries characteristics?
formed by endothelial cells, surrounded by basement membrane, no tunica media or tunica externa
100
fenestrated capillaries characteristics?
endothelial layer has pores (fenestrations), no tunica media or externa
101
where are fenestrated capillaries found?
kidneys, choroid plexus of ventricles in the brain and in endocrine glands
102
sinusoid capillaries characteristics?
incomplete or absent basement membrane and large fenestrations, allow proteins to pass
103
where are sinusoid capillaries found?
liver, new RBC, spleen, anterior pituitary and PTH glands
104
what happens if the papillary muscles are damaged?
cusps of AV valves don't close properly
105
what happens if semi-lunar valves are damaged
valve replacement
106
when the ventricles are contracting the:
AV valves are closed and the semi-lunar valves are open
107
when the ventricles are relaxed the:
AV valves are open and the semi-lunar valves are closed. the chordae tendineae are loose and the papillary muscles are relaxed
108
damage to which 2 valves is most detrimental to the cardiac system?
bicuspid and aortic valves
109
Aortic and pulmonary valvuloplasty
catheter inserted through vein in neck and implants inflating balloon which crushes plaque in valve cusps
110
annuloplasty rings
annulus rings that are placed around the natural annulus at the base of a heart valve. Used to reshape and strengthen the natural valve annulus
111
posterior leaflet repair
portion of leaflet removed and repaired and annuloplasty ring is added to stabilize and strengthen the repaired valve
112
mechanical valve replacement?
a long-lasting valve made of durable materials
113
tissue valve replacement?
a valve made up of human or animal donor tissue
114
ross procedure
borrowing your healthy pulmonary valve and moving it into the position of the damaged valve
115
TAVI/TAVR procedure
transcatheter aortic valve replacement
116
why do veins have valves?
to prevent reverse blood flow (venous reflex)
117
varicose veins
twisted or enlarged veins that lead to pooling or back flow of blood in veins
118
what causes varicose veins?
vein wall weakness, history of blood clots, absence of vein valves, family history of varicose veins
119
how does muscle contraction help move venous blood?
skeletal muscle contraction compresses the blood and increases the pressure in that area. This forces blood closer to the heart where venous pressure is lower.
120
what three factors influence resistance of blood?
blood viscosity, total blood vessel length, blood vessel diameter
121
how does blood viscosity impact resistance?
as viscosity increases, resistance increases and flow decreases
122
what is viscosity affected by?
plasma proteins, formed elements and temperature
123
how does total blood vessel length impact resistance?
the longer the vessel, the greater the resistance and lower the flow
124
how does blood vessel diameter impact resistance?
increased diameter means less blood touching the vessel wall so less resistance as diameter increases
125
what equation describes the non-linear effect of blood vessel diameter on resistance?
Resistance = 1/r^4
126
what electrically insulates the atria from the ventricles?
the cardiac skeleton
127
what type of tissue is the cardiac skeleton consist of? and why?
dense connective tissue because it is not electrically excitable and prevents transmission of current between the chambers of the heart
128
how many bands of connective tissue are there? where are they located? and why?
4 bands of dense connective tissue that encircle the heart valves. Located around the base of the aorta, both AV valves and the pulmonary trunk. Provides a point of attachment for valve leaflets and the myocardium - electrically insulate the atrial cells from the ventricular cells
129
where is the AV node found?
at the center of the cardiac skeleton?
130
what is important about the location of the AV node?
the AV node proposes the action potential through the atrioventricular conducting system. This results in a delay in depolarization as the action potential is propagated through the AV bundle to the apex of the heart so the ventricles contract after the atria
131
what are the two types of cells that make up the electrical and mechanical system?
autorhythmic and contractile cells
132
order of electrical and mechanical events
electrical event precede mechanical events
133
what percent of cardiac cells are autorhythmic cells?
1%
134
what is the function of autorhythmic cells?
control heart beat and spontaneously produce action potentials
135
what causes the unstable resting potential of authorhythmic cells?
slow inflow of Na+ without compensating for outflow of K+
136
what allows autorhythmic cells to continuously depolarize and drift up to AP threshold?
If channels (funny channels)
137
how are autorhythmic cells connected to contractile cells?
gap junctions
138
where are autorythmic cells found in the conducting system?
SA node (cardiac pacemaker), AV node, internodal pathways: bundle of his, right and left bundle branch, and purkinje fibers
139
what is the only place where AP conducts from atria to the ventricles?
AV bundle or bundle of His
140
How fast does the sinoatrial (SA) node fire?
75-100 AP/min
141
how fast does the atrioventricular (AV) node fire?
50 impulses/min
142
how fast do the right and left bundle branch fire?
20-40 impulses/min
143
describe how action potentials in autorhythmic cells are propagated?
If channels spontaneously depolarize the cell to threshold as Na+ inflow exceeds K efflux. Voltage gated Ca channels open and Ca/Na flow into the cell from the ECF, depolarizing the cell. At peak, K+ channels open and K+ flows out of the cell to depolarize the cell back to resting membrane potential
144
what is the resting membrane potential of cardiac contractile cells?
-90 mV
145
what is the threshold for contractile cell depolarization?
-75 mV
146
what happens after contractile cells reach threshold?
rapid depolarization as Na+ channels open and Na moves into the cells
147
at what voltage do Na+ channels close? and what happens after?
at +30 mV, Na+ channels close and Na is pumped out of the cell
148
what causes the plateau in the action potential after NA is pumped out of the cell?
slow Ca+ channels open and Ca moves into the cell
149
how and when does repolarization occur in contractile cells?
slow Ca channels begin closing, slow potassium channel begin opening. K+ moves out of the cell and the cell repolarizes to resting membrane potential
150
what do slow Ca channel cause?
long absolute refractory period where contractile cells cannot be stimulated to contract again
151
what does long absolute refractory period prevent? and what does it allow?
tetany. allows ventricles to fill
152
where does Ca+ enter from?
ECF and SR
153
how does Ca+ leave the cell
pumped out by Na/Ca ATPase
154
relative refractory period
Na channels closed but can open if stronger stimulus is received
155
calcium-induced calcium release
calcium enters the cardiomyoctye via L-type calcium channels. Calcium activates ryanodine receptors on the SR to further increase calcium availability. As contraction ends, intracellular calcium returns to the SR via SERCA calcium channel pump
156
p-wave
SA node fires and atria depolarize
157
PQ or PR segment
time between the beginning of the P wave to the beginning of the QRS complex, interval between the beginning of the electrical excitation of the atria and the beginning of excitation of the ventricles. conduction of signal through AV node
158
QRS complex
ventricles depolarize and atria depolarize. atrial repolarization masked by ventricular depolarization. ventricles contract
159
T wave
ventricular repolarization
160
ST interval
interval between ventricular depolarization and repolarization
161
QRS duration
duration of ventricular muscle depolarization
162
QT interval
duration of contraction of the ventricle from ventricular depolarization and repolarization
163
R-R represents what?
one heart beat
164
bradycardia
slow heart beat <60 bpm
165
tachycardia
fast heart beat >100 bpm
166
what does a long PR interval reflect?
damage to the conducting pathway of AV node
167
what does a large QRS complex reflect?
enlarged heart
168
what causes a long QT interval?
electrolyte disturbances, medications, coronary ischemia, conduction problems, myocardial damage
169
what impacts the size of the T wave?
things that influence ventricular repolarization including starvation, low cardiac energy reserves, abnormal ion concentrations, coronary ischemia
170
what are the two phases within any one chamber?
systole = contraction
diastole = relaxation
171
how does blood pressure change during systole and diastole?
rises during systole, falls during diastole
172
what are the 8 steps of the cardiac cycle?
1. atrial contraction begins
2. atria eject blood into ventricles
3. atrial systole ends; AV valves close
4. isovolumetric ventricular contraction
5. ventricular ejection occurs
6. semi-lunar valves close
7. isovolumetric relaxation occurs
8. AV valves open and ventricles fill passively
173
end-diastolic volume?
volume of blood before contraction
174
end-systolic volume?
volume of blood after contraction
175
stroke volume?
the amount of blood pumped by one ventricle during contraction (SV = EDV - ESV)
176
ejection fraction
the percentage of EDV represented by SV
177
cardiac output
volume of blood pumped through circulatory system in 1 minute
178
what is the equation relating cardiac output to heart rate and stroke volume?
CO = HR (beats/min) x SV (mL/beat)
179
What is the name of the principal that describes how the greater the heart is stretched during filling, there greater the force of contraction and the greater amount of blood pumped into the aorta?
Frank Starling Principle
180
how does the sympathetic nervous system affect the heart?
increases contractibility to muscle which makes the heart a stronger pump and increases the volume of blood pumped and the force of contraction
181
what does the SNS do to peripheral vessels?
contracts
182
What does the SNS do to cardiac output?
increase it
183
What are the 5 electrical steps of the conducting system?
1. SA node activity and atrial activation begins
2. stimulus spreads across the atrial surfaces and reaches the AV node
3. 100-msec delay at AV node while atrial contraction begins
4. impulse travels within the AV bundle and the bundle branches to the Purkinje fibers and via the moderator band to the papillary muscles of the right ventricle
5. the impulse is distributed by Purkinje fibers and relayed through the ventricles. Atrial contraction is completed and ventricular contraction begins
184
what are 5 risk factors for a heart attack?
age, obesity, high-stress job, hypertension, family history
185
what is the difference between cardiac arrest and a heart attack?
cardiac arrest is an electrical problem. It occurs when the heart malfunctions and stops beating unexpectedly. a heart attack is a circulation problem that occurs when blood flow to the heart is blocked
186
describe the parasympathetic stimulation of heart rate
releases Ach which activates cholinergic receptors that influence K and Ca channels in the pacemaker cells. The cel hyperpolarizes and decreases the rate of spontaneous depolarization. Heart rate slows
187
describe the sympathetic stimulation of heart rate
releases NE, which increases ion flow through If and Ca channels and depolarizes the cell to accelerate the rate of spontaneous depolarization. Heart rate increases
188
what are three circulating biomarkers that might be used to diagnose myocardial infarction?
myoglobin, creatine kinase, cardiac troponin
189
what are the three proteins of troponin complex and which are unique to cardiac tissue?
Troponin T, Troponin I, Troponin C. T & I are unique to cardiac tissue
190
when is myoglobin released?
when muscle tissue is damaged
191
is myoglobin specific to MI?
no, skeletal muscle also contains myoglobin so it is non-specific for MI
192
what form of creatine kinase is specific to myocardial cells?
MB type
193
what does cardiac troponin I bind to?
actin
194
what does cardiac troponin T bind to?
tropomyosin
195
where does lipid begin to deposit in atherosclerosis?
between the intima and media
196
what does a healthy artery endothelial wall resist?
attachment of WBC
197
what starts the formation of a thrombus?
irritation of wall causes which then express adhesion molecules to capture leukocytes, differential into macrophage and ingest lipid that becomes foam cell
198
what happens after foam cells are formed?
migration of smooth muscle cells make more extracellular matrix
199
how does a thrombus form?
fibrous cap of plague ruptures, platelets rush in and cause blood coagulation which triggers the development of a thrombus
200
what is the danger of a thrombus?
impairs blood flow
201
what part of the fibrous cap is most vulnerable to rupture?
shoulders of the cap
202
when does Acute coronary syndrome happen?
when atherosclerotic plagues become unstable and cause partial or total occlusion of a coronary artery
203
true or false, people often have abrupt change from stable ischemic heart disease or asymptomatic heart disease to ACS?
true
204
true or false, many of the ACS occur in individuals that do not have significant occlusion of the vessel?
true
205
what is stemi on a ECG?
ST elevation
206
what ECG represents muscle ischemia?
NSTEMI T wave inversion
207
two categories of ACS
NSTE-ACS which is non-st elevation myocardial infarction have incomplete to transient obstruction of blood flow in a coronary artery
STEMI- ST segment elevation myocardial infarction have an occlusive thrombus
208
what is the preferred immediate treatment for STEMI?
PCI - percutaneous coronary interventions
209
what does PCI do?
opens and stabilizes the artery lumen
210
why has mortality decreased for ACS?
stabilize with aspirin, heparin and nitroglycerin, thrombolysis (clot busters), PCI
