Exam 2 Flashcards
(141 cards)
1
Q
Purposes of the cardiovascular system
A
Transport O2 to tissues & removal of waste
Transport of nutrients to tissues
Regulation of body temperature
2
Q
Circulatory System includes
A
Heart
Arteries & arterioles
Capillaries
Veins & venules
3
Q
Arteries & arterioles
A
Carry blood away from heart
4
Q
Heart
A
Pumps blood
5
Q
Capillaries
A
Exchange site for nutrients & waste products between tissues & circulation
6
Q
Veins & venules
A
Carry blood toward heart
7
Q
Composition of Blood:
A
Composed of liquid plasma & formed elements
Erythrocytes, or red blood cells (RBCs)
Leukocytes, or white blood cells (WBCs)
Platelets
8
Q
Hematocrit
A
Percentage of total blood volume comprised of RBCs (~45% men, 40% women)
9
Q
Blood vessels
A
Blood transported in closed system of vessels that begins & ends @ heart
10
Q
Platelets involved with
A
clotting
11
Q
3 major types of vessels
A
arteries, capillaries, & veins
12
Q
Arteries carry blood
A
away from heart
13
Q
Veins carry blood
A
toward heart
14
Q
Capillaries
A
contact tissue cells & directly serve cellular needs by moving blood both in and out of tissues
15
Q
Low pressure system
A
veins
16
Q
High pressure system
A
arteries
17
Q
Thicker and more elastic vessel
A
arteries
18
Q
Anastomoses or shunts
A
arteries, arterioles, capillaries, veins & venules are either open or selectively by-passed bc blood supply is insufficient for all vascular networks to be simultaneously open (it’s routed to where it is most needed at a particular time)
19
Q
Pulmonary circuit side of heart
A
right
20
Q
Pulmonary circuit pumps de/oxygenated blood to WHERE via WHAT
A
deoxygenated to lungs via pulmonary arteries
21
Q
Systemic circuit side of heart
A
left
22
Q
Systemic circuit pumps de/oxygenated blood to WHERE via WHAT
A
oxygenated to whole body via arteries
23
Q
Systemic circuit returns de/oxygenated blood to WHERE via WHAT
A
Returns deoxygenated blood to right heart via veins
24
Q
Pulmonary circuit returns de/oxygenated blood to WHERE via WHAT
A
Returns oxygenated blood to left heart via pulmonary veins
25
Epicardium function
lubricative outer covering of heart
26
Myocardium function
provides muscular contractions that eject blood from heart chambers
27
Cardiac cycle
systole (contraction phase) and diastole (relaxation phase)
28
Valves
promote blood flow in 1 direction
29
Pulmonary valve
top left-right ventricle to pulmonary artery
30
Tricuspid valve
bottom left-right atrium to right ventricle
31
Aortic valve
top right- left ventricle to aorta
32
Bicuspid valve
bottom right- left atrium to left ventricle
33
Left ventricle
walls are thicker, stronger, and more elastic than others bc it pumps blood throughout whole body
34
More time in diastole/systole in exercise than rest
systole
35
More time in diastole/systole at rest than exercise
diastole
36
BP
Force per unit area exerted on wall of a blood vessel by its contained blood
Measured in reference to systemic arterial BP in large arteries near heart
mm Hg
Differences in BP w/in vascular system provide driving force that keeps blood moving from higher to lower pressure areas
37
Resistance
Opposition to flow
Measure of amount of friction blood encounters as it passes through vessels
referred to as peripheral resistance (PR) or total peripheral resistance (TPR)
38
Resistance generally encountered in...
systemic circulation
39
3 important sources of resistance are:
blood viscosity
total blood vessel length
blood vessel internal diameter
40
Resistance factors that remain relatively constant are:
Blood viscosity – thickness
Blood vessel length – longer the vessel, the greater the resistance encountered
41
Major determinants of peripheral resistance
Small-diameter arterioles
42
Fatty plaques from atherosclerosis contribute to...
a decrease in internal diameter (decreased opening for blood flow)
43
Fatty plaques from atherosclerosis cause:
turbulent blood flow
Turbulence dramatically increases resistance
44
Resistance varies
inversely with 4th power of vessel radius
45
Blood flow (F) inversely proportional to
resistance (R)
if R increases, blood flow decreases
46
Blood flow (F) directly proportional to difference in WHAT between 2 points in circulation
BP
if difference in pressure increases, blood flow speeds up
47
Is resistance or difference in pressure more important in influencing local blood pressure
resistance (R)
48
Arterial BP reflects 3 factors of arteries close to heart
1) elasticity (distensibility & recoil)
2) compliance (distensibility & lack of recoil)
3) volume of blood forced into them @ any given time
49
Systolic pressure
Top #
pressure exerted on arterial walls during ventricular CONTRACTION
highest reading
LEFT VENTRICLE
50
Diastolic pressure
Bottom #
arterial pressure during cardiac RELAXATION
lowest reading
RIGHT VENTRICLE
51
Pulse pressure
difference between systolic & diastolic pressure
52
Mean arterial pressure (MAP)
pressure that propels blood to tissues
=diastolic pressure + ⅓ pulse pressure
53
Blood flows along what kind of gradient
pressure; always moving from high to low
54
Pressure results when...
flow is opposed by resistance
55
Steepest change in BP occurs in...
arterioles
56
Systemic pressure
Is highest in aorta
Declines throughout length of pathway
Is 0 mm Hg in right atrium
57
Q
cardiac output: volume of blood pumped by heart per min.
4-6 L/min @ rest
= HR x stroke volume
58
Main factors influencing blood pressure (3)
cardiac output (Q)
Peripheral resistance (PR)
Blood volume
59
Q x PR =
BP
cardiac output X peripheral resistance
60
BP varies directly w/
Q
PR
Blood volume
61
Normal BP
~120/80 mmHg
62
High BP
>= 140/90 mmHg(hypertension)
63
Low BP
<= 90/60 mmHg (hypotension)
64
Factors That Increase Arterial Blood Pressure
```
blood volume increases
heart rate increases
stroke volume increases
blood viscosity increases
PR increases
```
65
Venous BP alone is too low to promote adequate blood return & is aided by
respiratory pump: pressure changes by ventilation
muscular pump: skeletal muscles move blood toward heart
1 way valves in peripheral veins prevent back flow against gravity
66
Contraction of heart depends on electrical stimulation of...
myocardium
67
Impulse is initiated in...
right atrium (deoxygenated blood side)
68
Electrocardiogram (ECG/EKG)
records electrical activity of heart
abnormalities may= coronary heart disease
ST segment depression may= myocardial ischemia
69
P-wave
atrial depolarization
70
QRS complex
ventricular depolarization
71
T-wave
ventricular repolarization
72
Stroke volume (SV)
volume of blood ejected per ventricular contraction
| usually L ventricle
73
Parasympathetic nervous system:
increase/decrease HR?
via?
affects SA node how?
decrease in HR
vagus nerve
inhibits SA node
74
Sympathetic nervous system:
increase/decrease HR?
via?
affects SA node how?
increase in HR
cardiac accelerator nerves
stimulates SA node
75
Hormones that increase heart rate
epinephrine & thyroxine
76
Regulates SV
End-diastolic volume (EDV)
average aortic BP
ventricular contractility
77
EDV
Frank-Starling Law
volume of blood in ventricles @ end of diastole
"preload"
Frank-Starling mechanism (law)
Greater preload results in stretch of ventricles & a concomitantly forceful contraction (because myocardium has elastic qualities)
78
EDV affected by
```
Venoconstriction (+)
Skeletal muscle pump (+)
Respiratory pump (+)
```
79
Average aortic pressure
pressure the heart pumps against to eject blood
"afterload"
aortic pressure inversely related to SV
80
Ventricular contractility
increased contractility=higher stroke volume
81
Cardiac output=
cardiac rate x SV
82
Plasma
liquid portion of blood
| -ions, proteins, hormones
83
Cells
solid portion of blood
| -RBC, WBC, platelets
84
Hematocrit %
~ 40-45%
85
2 major adjustments of blood flow
increased cardiac output
| redistribution of blood flow (less blood to visceral organs and more to active muscles)
86
Q (cardiac output) increases due to:
increased HR and SV (plateaus @ ~40% VO2 max)
87
Circulatory responses to exercise
HR and BP depend on type, intensity, & duration of exercise, environmental conditions, & emotional state
88
Rest -> exercise
rapid increase in HR, SV, & Q
89
Incremental exercise
```
HR & Q
-increase linearly w/ increasing work rate
-plateaus @ 100% VO2max
systolic BP
-increases w/ increasing work rate
```
90
At same oxygen uptake arm work results in higher:
HR: Due to higher sympathetic stimulation
BP: Due to vasoconstriction of large inactive muscle mass
91
Prolonged exercise
Q maintained by: gradual decrease in SV & increase in HR
cardiovascular drift: bc dehydration & increased skin blood flow (rising core temp)
92
Cardio control during exercise
1. initial signal to "drive" comes from higher brain centers
2. Fine tuned feedback:
-In skeletal muscle
-chemoreceptors: detect changes in blood
chemistry
-mechanoreceptors: detect joint actions
-baroreceptors: detect BP changes
93
Muscular endurance
ability of muscle to sustain high intensity, repetitive, or static exercise repeated in 1-2 min bursts
muscular strength & anaerobic development
94
Cardiorespiratory endurance
ability of whole body to sustain prolonged, steady-state exercise
cardiovascular & respiratory system (aerobic) development
95
VO2 Max
highest rate of O2 consumption possible during max exercise
can be increased with endurance training
96
Submax endurance capacity
determined by VO2 max & lactate threshold
*more difficult to evaluate
can be increased with endurance training
97
Heart size w/ training
Left ventricle size & wall thickness increase
98
Fick equation evaluates?
a-VO2 diff.
oxygen uptake by active muscle tissue
arteriovenous volume of oxygen: diff in O2 concentration in arteries and veins
99
RHR
decreases with endurance training
100
Bradycardia
slow HR
| RHR: 30-40 bpm
101
Tachycardia
fast HR
| RHR: >= 90 bpm
102
Submax HR during exercise
decreases with training
103
Max HR during exercise
remains unchanged
104
Gradience
moving from an area of high to low
can be anything (temp./concentration/etc.)
105
Systemic Circulation Overview
- blood leaves via arteries that become capillaries
- O2 and nutrients diffuse across capillary walls and enter tissues
- CO2 and waste is removed from tissues into the blood
- O2 deficient blood goes to lungs where it releases CO2 and picks up O2 at alveolar sacks
- O2 rich blood returns to the heart
106
What happens if there is no gradience?
there is no driving force
107
What is the blood made up of?
-plasma and formed elements
108
what are the formed elements in the blood?
- erythrocytes (RBC)
- Leukocytes (WBC)
- platelets
109
What do RBC's do?
carry oxygen and carbon dioxide
110
What are the two circuit systems?
pulmonary and systemic
111
What is the flow of blood in the heart? IN DETAIL
enters through vena cava to the right atrium, through the tricuspid valve to the right ventricle, through the pulmonary valve, to the pulmonary artery to the capillaries to the lungs (where co2 and 02 exchange takes place and waste is removed), back to capillaries to the pulmonary vein, to the left atrium, to the left ventricle, through the aortic valve, to the aorta, and finally to the rest of the body
112
Blood is the body's only what?
fluid tissue
113
Why would hematocrit be low?
because o2 supply is low and rbc's carry o2 and rbc's make up hematocrit
114
plasma
cellular portion of the cell
115
Percentages in the blood?
Plasma-55%
Erythrocytes-45%
Buffy coat(leukocytes and platelets)- <1%
116
the process of separating blood through a _______
centrifuge
117
Arterial Vessels
high pressure
thick, strong walls
elasticity in walls
118
Venus Vessels
low pressure
no elasticity in walls
119
Facts about the circulatory system
- blood supply is not sufficient enough to have all vascular networks open at one time
- blood is prioritized and sent to the areas where it is needed most (the brain is most frequent)
- to reroute blood, arteries/arterioles, veins/venules, and capillaries are either open or selectively bypassed by shunts or anastomoses
120
if sphincters are closed.....
shunts or anastomoses are open
121
Superior and Inferior Vena Cave
- low pressure systems
| - one way valves
122
Aneurism
weakness within the heart wall
123
Chordae tendineae and papillary muscle
support valve inside the chamber
124
interventricular septum
division between the left and right side of the heart
125
Pulmonary circuit
low pressure system that pumps deoxygenated blood to lungs (PA) and returns oxygenated blood to heart (PV)
126
Systemic Circuit
high pressure system that carries oxygenated blood to entire body (aorta), and returns deoxygenated blood to the right side of the heart (veins or venus system)
127
Coronary Vessels
Two pairs of blood vessels (the coronary arteries and coronary veins) that supply the muscles of the heart itself
128
Myocardium
provides muscular contractions that eject blood from the heart chambers
129
epicardium
serves as a lubricative outer covering
130
layers of the heart muscle (outer to inner)
pericardium, epicardium, myocardium, endocardium
131
during exercise, systole or diastole is longer?
systole is relatively longer
132
in the absence of blood pressure?
someone will die
133
BP in arteriole system?
force per unit area exerted on wall of blood vessel by its contained blood
134
BP in vascular system?
provides the driving force that keeps blood moving from high to low pressure areas (pressure gradient)
135
BP is expressed?
millimeters of mercury per g (mm Hg)
136
Artificially Induced Polycythemia
hematocrit levels are up
thick blood (high viscosity)
dehydration
137
In terms of resistance, the longer the blood vessel....
the greater the resistance encountered
138
orm of low blood pressure that happens when you stand up from sitting or lying down
orthostatic hypotension
139
In reference to resistance, vessel internal diameter....
- changes are frequent
| - varies inversely(internally) with 4th power of vessel radius
140
Vessel radius is normal what?
1/2 diameter
141
carotid intima-media thickness
resistance in a major artery
