WEEK 1 Cardiovascular Anat & Phys Flashcards
1
Q
The left side of the heart extends from which costal cartilage to which intercostal space?
A
2nd cc to 5th ic
2
Q
The right side of the heart extends between which costal cartilages?
A
3rd-6th
3
Q
The apex of the heart lies to the left of which line?
A
mid sternal
4
Q
Which layer of the heart encloses it? Name the 2 layers it contains.
A
pericardium (parietal & visceral)
5
Q
Which layer of the pericardium is a fibrous relatively unyielding outer layer that forms a sac & contains terminal branches of several blood vessels?
A
parietal
6
Q
Which layer of the pericardium is the inner layer which forms pericardial fluid to moisten the heart to prevent friction & maintain heart in position?
A
visceral (epicardium)
7
Q
Where are coronary blood vessels located?
A
epicardium
8
Q
The cardiac muscle fibers in the ____________ provide work in distributing blood to heart.
A
myocardium
9
Q
Which layer is the innermost that lines the heart & contains smooth muscle?
A
endocardium
10
Q
When not enough blood reaches the ____________ layer, a MI occurs.
A
myocardium
11
Q
Which layer are infections & diseases of valves common?
A
endocardium
12
Q
The heart consists of 4 muscular chambers divided in half by what?
A
oblique longitudinal septum
13
Q
The _____________ receives blood from veins while the _____________ eject blood through arteries.
A
- atria
- ventricle
14
Q
Where does the oxygenated blood received by the left atria come from & where does it go?
A
pulmonary vein –> mitral (bicuspid valve) –> left ventricle
15
Q
Where does the blood received by the right atria come from & where does it go?
A
superior & inferior VC –> tricuspid valve –> right ventricle
16
Q
Where does the left ventricle eject blood to?
A
aortic valve –> aorta
17
Q
Where does the right ventricle eject oxygen deficient blood to?
A
pulmonic valve –> pulmonary trunk –> left & right pulmonary artery
18
Q
What type of vein is related to skeletal mm? How about smooth mm?
A
- skeletal: large
- smooth: venules
19
Q
What structure allows arterioles to dilate & constrict?
A
smooth muscle
20
Q
T/F: venule have the same amount of smooth muscle as arterioles.
A
F (less)
21
Q
If the right side of the heart isn’t pumping well, the blood will end back in the body which leads to swelling where?
A
- legs
- abdomen
- peripheries
22
Q
Arteries are ____________ reservoirs that maintain blood flow during ventricular relaxation while veins are ____________ reservoirs.
A
- pressure
- volume
23
Q
Which nutrient is required for heart contraction?
A
calcium
24
Q
Myocardial tissue contains ___________ & ___________ myofilaments similar to skeletal mm.
A
- actin
- myosin
25
What are the 3 properties of myocardial cells? Describe each.
- automaticity: contract w/o external stimuli
- rhythmicity: contract in rhythmic manner
- conductivity: nerve impulses can go from 1 myocardial cell to another bc of intercalated discs that form a syncytium
26
What are the 2 junctions of intercalated discs? What are their functions?
- desmosomes: attach 1 cell to another
- connexins: allow electrical impulses to spread from 1 cell to another
27
What does the right coronary artery supply? What does it branch into?
- right ventricle
- AV node (in 55% of ppl)
- SA node
Branches into:
- right posterior descending
- right marginal
28
What does the left coronary artery supply? What does it branch into?
- left ventricle
- left atrium
- ventricular septum
- SA node (45% of ppl)
Branches into:
- left anterior descending
- left circumflex arteries
- left marginal
29
T/F: sequential contraction occurs w/ atria first & ventricles second.
T
30
The SA node functions as the pacemaker of the heart by setting a pace of depolarization faster than any other myocardial cell & can be found where?
upper portion of right atrium
31
Define chronotropic & inotropic.
- chrono: speed of contraction
- ino: strength of contraction
32
The SA node paces the heart to more than ____ beats per minute w/o any other input.
100
33
How does input from the autonomic NS affect SA node?
- sympathetic: increases HR & myocardial contractility
- para: decreases HR & myo contractility to 60-90 bpm
34
Which neurotransmitter plays a key role in HR for sympathetic & para NS?
- sym: norepinephrine
- para: acetylcholine
35
Via which nerve does the parasympathetic NS exert its effects?
vagus
36
T/F: the electrical signal is sped up once it gets to AV node from SA.
F (slowed down)
37
SA node transmits impulses to ____________ to cause them to contract.
atria
38
Where is the AV node located?
floor of right atrium
39
The AV node causes ventricles to contract how many seconds later?
0.04
40
At what rate can the AV node spontaneously discharge w/o external stimuli?
40-60 bpm
41
Which node is commonly the cause of arrhythmias?
AV
42
AV node impulses are transmitted to the ventricular myocardium through what? What does that divide into?
bundle of his --> left & right bundle branch
43
Where does the bundle of his divide? Why?
intermuscular septum to innervate each ventricle
44
What do the bundle branches divide into? What is the significance of this?
purkinje fibers which cause the ventricles to contract
45
Which node is susceptible to disease bc of proximity to epicardium (pericarditis) & coronary artery occlusion?
SA
46
AV node is susceptible to disease due to _________ coronary artery occlusion.
right
47
Describe what each represents during the ECG:
- P wave
- PR interval
- QRS complex
- QT interval
- T wave
- P: atrial depolarization
- PR: conducting time b/t atrium & ventricle
- QRS: ventricular depolarization
- QT: time for ventricles to depolarize then repolarize
- T: ventricular repolarization
48
What abnormal lab value would lead to arrhythmias & mm cramps (esp if taking a diuretic)?
hypokalemia (potassium)
49
What abnormal lab value would lead to nausea & vomiting?
hyperkalemia
50
What abnormal lab value would lead to erratic cardiac contraction?
hypercalcemia
51
What abnormal lab value would lead to decreased myocardial contractility?
hypocalcemia
52
Slow influx of ____ (prepotential) --> rapid influx of ____ (depolarization) --> outflux of ____ (repolarization).
- Na+
- Ca2+
- K+
53
1 cardiac cycle lasts 0.8 sec for a HR of ____ bpm.
75
54
What are the 2 primary phases of a cardiac cycle? Describe what happens in each.
- systole: myocardial contraction
- diastole: myocardial relaxation
55
What phase is this?
- all heart muscle in relaxation
- all heart valves are closed
- blood returning to atria.
atrial diastole or ventricular diastole
56
What phase is this?
- atria in contraction
- AV valves open
- blood to ventricles.
atrial systole
57
What phase is this?
- ventricles in contraction
- semilunar valves open
- blood passing to arteries.
ventricular systole
58
What is the order of atrial & ventricular diastole & systole?
atrial diastole --> atrial systole --> ventricular systole --> ventricular diastole
59
What is the cardiac output @ rest & how much does it increase w/ exercise?
- 5-6 L of blood
- 4-7x resting
60
What 3 factors contribute to BP?
- HR
- SV
- total peripheral resistance
61
CO affects __________ BP while TPR affects ___________ BP.
- systolic
- diastolic
62
What is the formula for mean arterial blood pressure (MAP)?
DBP + 1/3 (SBP-DBP)
63
What is the normal MAP if there's a BP of 120/80?
93
64
What is the MAP for patients w/ hypotension?
60
65
Describe each BP category:
- normal
- elevated
- hypertension stage 1
- stage 2
- hypertensive crisis
- normal: s: less than 120 & d: less than 80
- elevated: s: 120-129 & d: less than 80
- stage 1: s: 130-139 or d: 80-89
- stage 2: s: 140 or higher or d: 90 or higher
- crisis: s: higher than 180 &/or d: higher than 120
66
What 4 factors determine mean arterial blood pressure?
- blood volume
- CO
- resistance of system to blood flow
- relative distribution of blood b/t arterial & venous blood vessels
67
Explain why individuals laying down will have a higher BP.
blood is evenly distributed in veins --> increased central venous pressure --> increased end-diastolic volume --> increased stroke volume --> increased pulse pressure
also lower when standing bc blood pooling in legs so less going to heart
68
HR is affected by baroreceptors which can be found where?
- carotid sinus
- aortic arch
69
What is the term for amt of blood pumped @ each beat?
stroke volume
70
What is the term for amount of left ventricular blood volume prior to contraction?
pre-load (end diastolic volume)
71
If there's an increase in preload, what happens to SV? What happens to EDV?
- increases
- increases
72
If there's an increase in afterload, what happens to SV? What happens to ESV?
- decreases
- increases
73
If there's an increase in inotropy, what happens to SV? What happens to ESV?
- increases
- decreases
74
SV is affected by cardiac preload, venous return, total blood volume, __________ atrial contraction & __________ ventricular function.
left
75
Afterload is the amt of resistance (pressure) encountered by left ventricle (__________ pressure) or by right ventricle (___________ ___________ pressure) during systole.
- aortic
- pulmonary artery
76
If BP is too high, what happens to SV?
drops
77
During exercise, SV increases up to ___ - ___% of VO2 max then levels off.
40-60
78
What is the term for amt of ventricular blood volume pumped per heart beat?
ejection fraction
79
What is the formula for ejection fraction?
stroke volume / end diastolic volume
80
What is the normal value of ejection fraction @ left ventricle?
55-70%
81
In which type of heart failure (systolic vs diastolic) is there low ejection fraction?
systolic
82
T/F: diastolic heart failure results in normal or elevated ejection fraction.
T
83
If SV decreases, what happens to ejection fraction?
decreases
84
How is HR related to filling time?
inversely affects so there's more fill when HR is lower
85
What is the term for blood leftover when heart contracts?
ESV
86
What causes heart valves to close?
high pressure from atria & ventricles
87
What are the 2 AV valves & their respective sides? How many leaflets does each have?
- mitral: left, 2
- tricuspid: right, 3
88
Which structures help AV valves attach to ventricular surfaces?
- chordae tendinae
- papillary muscle
89
How many leaflets do aortic & pulmonary valves have?
3
90
Where do aortic & pulmonary valves attach?
blood vessels they eject to
91
Describe the normal valve closure sequence.
- atrial & ventricular systole begins
- ventricles contract: ventricular pressure > atrial pressure (tricuspid & mitral valves close)
- ventricular pressure > aortic & pulmonary artery pressure (aortic & pulmonic valves open)
- ejection complete
- ventricular pressure < aortic & pulmonary artery pressure (aortic & pulmonic valves close)
- ventricular pressure < atrial pressure (mitral & tricuspid valves open)
- diastolic filling occurs
- myocardial depolarization
92
Which heart sound has lower pitch & lasts longer?
S1
93
Which heart sound is the closure of aortic & pulmonic valves? What about AV valves?
- A&P: S2
- AV: S1
94
For heart sounds, the order is S1 --> ___________ pulse --> S2.
carotid
95
Which valve can be heard @ 2nd-3rd right interspace? What about the left?
- right: aortic
- left: pulmonary
96
Where can the tricuspid & mitral valve be heard?
- tricuspid: left sternal border
- mitral: apex
97
Blood makes up ___-___% of body weight w/ average size man w/ 12 pints & woman w/ 9.
7-8
98
What 4 components make up blood volume?
- venous compartment
- systemic arteries
- pulmonary circulation
- capillaries
99
What 3 components make up blood? Give % of each.
- plasma (55%)
- RBCs (45%)
- WBCs & platelets (<1%)
100
Which component of blood contains glucose, proteins, & salts?
plasma
101
___________ are not a blood cell but are involved in production of platelets to promote clotting.
thrombocytes
102
Where does hematopoiesis (production of RBCs) take place?
cancellous spongy bone (ex: bone marrow)
103
RBC production is regulated by which hormone produced by the kidneys?
erythropoietin
104
What measures the conc of RBCs in blood & assesses O2 carrying capability of blood?
hematocrit
105
What can lead to high levels of RBCs?
- dehydration
- polycythemia vera
- heart & lung disease
106
___% of O2 is bound to HgB while ___% of O2 is dissolved in plasma.
- 97
- 2
107
What is the term for amount of O2 that is bound to HgB?
O2 saturation (SaO2)
108
What is the normal % of SaO2?
95-97
109
There will be no increased SaO2 if PaO2 is at what value?
>= 50 mmHg
110
Bound O2 can be released to blood if PaO2 levels drop to what value?
< 50 mmHg
111
Rate of release of bound O2 is significantly elevated when SaO2 is less than what percentage?
80
112
How would these impact release of O2?
- increased temp
- increased 2-3 DPG
- increased [H+]
- exercise
- diseases that increase tissue metabolism
increase release
113
How would these impact release of O2?
- decreased temp
- decreased 2-3 DPG
- decreased [H+]
- CO
- medically induced coma
- decreased metabolism
decrease release
114
What innervates arterioles?
sympathetic post ganglionic fibers
115
Which type of pressure tends to move blood across capillary membrane into interstitium?
capillary hydrostatic
116
What are the steps in the oxygen transport system?
1. Ventilation
2. Pulmonary O2 diffusion
3. Circulatory O2 delivery
4. Muscle O2 diffusion
5. Muscle O2 utilization
6. Muscle ATP turnover
117
Increased activation of autonomic NS causes ___________ while reduced activation causes ___________.
Increased activation causes vasoconstriction while reduced activation causes vasodilation.
118
Where does capillary hydrostatic pressure originate from?
Blood pressure.
119
Which type of pressure has albumin to increase osmolarity within capillary vessels as compared to interstitial fluid leading to flow of interstitial fluid into capillary circulation?
Capillary oncotic pressure.
120
Which type of pressure moves fluid back into microcirculation?
Interstitial hydrostatic pressure.
121
Which type of pressure draws fluid out of microcirculation into interstitium?
Interstitial oncotic pressure.
122
What is the Fick equation to determine VO2?
HR x SV x (a-vO2 diff)
123
What is the value of net fluid exchange?
2 mmHg outwards from capillary.
124
At rest, what % of CO does each of these receive? Muscles, mesenteric, splenic, & portal tissues, brain & myocardium.
Muscles: 10-15%
Mesenteric, etc.: 20-30%
Brain & myocardium: 5% (remains steady)
125
With vigorous exercise, muscles receive ____-____% of CO while tissue beds of other organs are reduced.
80-85%
126
How do oxygen delivery & consumption react as tissue metabolism increases?
Also increases.
127
At rest, ___% of O2 is extracted from peripheral circulation by tissue cells since there's higher concentration in blood.
23%
128
What's the difference between hypoxemia & hypoxia?
Hypoxemia: O2 low in blood
Hypoxia: O2 low at tissues.
129
How does VO2 & tissue metabolism change as DO2 decreases?
VO2 does not decrease as tissues will still try to use the same relative amount of O2; tissue metabolism decreases to survive on less amount of O2.
130
If VO2 falls below a critical level, what will happen?
Anaerobic metabolism
Serum lactate increase
Multi-organ system failure
Sedation to reduce tissue metabolism.
131
Approx ____ million alveoli are present in normal lungs.
300
132
How does O2 diffuse across alveoli membrane to pulmonary arterial circulation?
Moves to capillary system --> venules --> returned to heart via pulmonary vein.
133
How does CO2 diffuse across alveoli membrane to pulmonary venous circulation?
Moves to capillary system --> arterioles --> lung via pulmonary artery --> exhaled.
134
What allows for there to be diffusion of O2 from alveoli to capillaries?
Less O2 in capillaries.
135
What 4 factors affect the diffusion of O2 & CO2 across alveoli to pulmonary arterial circulation?
1. Area of capillary membrane
2. Diffusion capacity of alveolar capillary membrane
3. Pulmonary capillary volume
4. V/Q ratio
136
What is the term for the structure along the capillary membrane that increases surface area for diffusion to prevent decreased gas exchange & hypoxemia?
Invaginations.
137
What 4 factors contribute to changes in effective SA of gas exchange membrane?
1. Pathology
2. Posture
3. V/Q mismatch
4. Lung volume
138
What is the #1 reason for hypoxemia?
V/Q mismatch.
139
What type of changes affects the diffusion capacity of alveolar capillary membrane?
1. Effective SA of gas exchange membrane (pathology, posture, V/Q mismatch, lung volume)
2. Physical properties of membrane
3. Uptake of gases by RBC.
140
Pulmonary capillary volume (increases/decreases) with exercise.
Increases.
141
Pulmonary capillary volume has (increased/decreased) velocity to allow for gas transfer in 0.25 secs.
Decreased.
142
What is the term for blood flow to alveoli?
Perfusion.
143
Which part of the lung is ventilation increased when upright? How about perfusion? Explain.
Higher parts of the lung (apices) because gravity makes blood pool to lower parts where perfusion would be higher.
144
If there's more ventilation, describe how V/Q is affected & what this means.
V/Q increases; no gas exchange occurs because of 'dead space.'
145
If there's more perfusion, describe how V/Q is affected & what this means.
V/Q decreases; blood shunted to other parts of lung.
146
What is pure dead space?
Upper airways (e.g., trachea) where no gas exchange occurs because there are no alveoli.
147
What happens if ventilation volume is too large for relative blood flow?
Vasodilation occurs at arterioles --> increased blood flow.
148
What happens if ventilation volume is too small for relative blood flow?
Vasoconstriction occurs at arterioles --> decreased blood flow.
149
____________ blood surrounds capillaries to allow gas exchange to happen.
Venous.
150
What is the normal V/Q ratio for the entire lung?
0.8.
151
How would pulmonary embolus affect V/Q ratio? How about obstruction?
Pulmonary embolus: increase
Obstruction: decrease.
152
During exercise, how does blood move about the lung?
Goes from lower --> higher parts.
153
If a patient is laying flat on their back, which part of the lung is more perfused?
Posterior.
154
(Large/Small) arteries have higher concentration of smooth muscle to allow for control of blood flow via vasodilation or vasoconstriction.
Small.
155
Why do larger arteries have higher elastic properties?
To accommodate for higher blood pressures & movement of blood during diastole.
156
True or False: Arteries are more elastic than veins because they act more as a reservoir.
False (veins).
157
What 2 systems extrinsically control vasoconstriction & vasodilation of arterioles?
1. Endocrine
2. Autonomic nervous.
158
Vasodilation induced by local tissue reductions in O2 or increased production of what?
1. H+ ions
2. CO2
3. Metabolites.
159
The endocrine system is under control of the ____________.
Hypothalamus.
160
What releases epinephrine?
Adrenal medulla.
161
What does epinephrine cause?
1. Vasoconstriction at a-receptors
2. Vasodilation at b-receptors.
162
Where are vasoconstriction a-receptors & why?
In skin, mesenteric, splenic arterioles to shunt blood to skeletal muscle.
163
Where are vasodilation b-receptors & why?
In skeletal muscle arterioles to increase blood flow; in airways to increase ventilation & perfusion (trachea, bronchioles, alveolar arterioles).
