A + P Cardiovascular System Flashcards
1
Q
main purposes of the cardiovascular system
A
delivery of oxygen, nutrients, hormones, etc. to tissues via the blood circulation
removal of CO2, waste products, metabolic intermediates, etc. from the tissues via the blood circulation
2
Q
CVS main components
A
blood
vessels
heart
3
Q
blood function
A
serves as the medium for delivery
4
Q
vessels function
A
pathways for the blood
5
Q
heart function
A
pump for the blood
6
Q
blood functions
A
transportation of nutrients, hormones, O2 and CO2, and waste products within the body
regulation of pH and ions within the body
restriction of fluid losses at injury sites
defense against toxins and pathogens
stabilization of body temperature
7
Q
blood tissue type
A
specialized connective tissue
8
Q
whole blood composition
A
plasma -albumens -globulins -fibrinogen formed elements
9
Q
plasma composition
A
fluid consisting of water, dissolved plasma proteins and other solutes
10
Q
formed elements composition
-specifics
A
cells and solids
- red blood cells - 99.9%
- white blood cells - <0.1%
11
Q
red blood cells function
-special note
A
transport O2 and CO2 on hemoglobin
special
-surface antigens on RBCs determine blood type A, B, AB, or O
12
Q
white blood cells function
A
part of the immune system
13
Q
platelets function
A
cell fragments involved in clotting
14
Q
blood characteristics
A
sticky
15
Q
three layers of blood vessels
A
tunica intima
tunica media
tunica externa
16
Q
tunica intima location and composition
A
innermost endothelial lining
17
Q
tunica media location and composition
A
middle layer
contains smooth muscle
18
Q
tunica externa location and function
A
outermost layer
anchors vessels to adjacent tissues
19
Q
vessels can contract/relax, which is called
A
vasoconstriction/vasodilation
20
Q
vessel categories
A
arteries arterioles capillaries venules veins
21
Q
arteries
characteristics
A
largest vessels for systemic blood delivery
have thick, muscular walls and are highly elastic to withstand high pressures
-no gas exchange can occur
22
Q
arterioles
characteristics
A
smaller branch of arteries
have thin but muscular walls that can contract to direct blood flow
23
Q
capillaries
characteristics
A
smallest vessels
thin walls permit gas exchange
no muscle control blood flow
24
Q
venules
characteristics
A
smaller branch of veins
thin, compliant walls help store a lot of blood
one-way valves facilitate blood flow
25
veins
| characteristics
largest vessels for systemic blood return
have compliant, muscular walls
one-way valves to store and/or pump blood back to the heart
26
heart
- function
- location
pump for the blood and connects with the vessels to distribute blood around the body
sits between two pleural cavities in the mediastinum
27
heart layers
pericardium
epicardium
myocardium
endocardium
28
pericardium function
covering for the heart
function
-a sac-like structure that surrounds, lubricates, and protects the heart and root of the great blood vessels
comprised of two layers
29
pericardium two layers
parietal pericardium
-outer layers
visceral pericardium
-inner layer
30
epicardium
| -function
outer layer
function
-responsible for producing the pericardial fluid
31
myocardium
| functions
middle layer
functions
-primary muscle tissue of the heart
-contains short, branched, single-nucleated cells (myocytes)
32
myocyte functions
| -control type
utilize gap junctions (intercalated discs) to propagate electrical signals quickly for synchronized cardiac contraction
-involuntarily and automatically controlled
33
endocardium
- composition
- functions
inner layer
comprised mostly of epithelial cells to create a smooth lining inside the chambers of the heart
creates an ionic barrier between blood and cardiac tissue
34
heart chambers
```
right atrium (RA)
right ventricle (RV)
left atrium (LA)
left ventricle (LV)
```
35
right atrium
| -function
collects de-oxygenated venous blood from systemic circulation via the superior and inferior vena cava and pumps it into the right ventricle
36
right ventricle
| -function
receives de-oxygenated blood from the right atrium and pumps it through the pulmonary artery to the lungs
37
left atrium
| -function
collects oxygenated blood from the lungs via the pulmonary vein and pumps it into the left ventricle
38
left ventricle
| -function
receives oxygenated blood from the left atrium and pumps blood through the aorta into systemic circulation
39
specialized heart valves
-functions
types
```
functions
-separate the chambers
-regulate the blood flow within the heart
types
-atrioventricular (AV)
-similunar (SL)
```
40
atrioventricular valve types
tricuspid valve
| mitral (bicuspid) valve
41
tricuspid valve function
allows the blood to flow from the right atrium into the right ventricle
42
mitral (bicuspid) valve function
allows the blood to flow from the left atrium into the left ventricle
43
semilunar valve types
pulmomary valve
| aortic valve
44
pulmonary valve functions
allows blood to flow from the right ventricle into the pulmonary artery (then to the lungs for reoxygenation)
45
aortic valve function
allows blood to flow from the left ventricle into the aorta (then out to the systemic circulation)
46
functions of specialized structures within the heart that behave like muscle and nervous tissues
initiate and/or conduct APs, which depolarize surrounding myocytes to produce myocardial contraction (heart beat)
47
names of these structures
sinoatrial (SA) node
atrioventricular (AV) node
Bundle of His (AV bundle)
Purkinje fibers
48
SA node
- location
- functions
- 2 special notes
located in right atrium
heartbeat is initiated here via depolarization of atria
2 notes
-spontaneously depolarizes at a regular rhythm, hence its nickname as the "pacemaker" of the heart
-the ANS also innervates the SA node to influence node activity and can, therefore, control HR
49
AV node
- location
- functions
located in right atrium
functions
-receives depolarization signal from SA node and delays it to give both atria time to contract before sending the signal to the Bundle of His
50
Bundle of His
- location
- function
located in between the right and left atria and ventricles
function
-gives rise to bundle branches in the interventricular septum
-bundles relay the signal to depolarize the Purkinje fibers
51
Purkinje fibers
- location
- function
terminal innervations within the myocardium of the right and left ventricles
function
-receive signal to depolarize and stimulate both ventricles to contract
52
circulation
| -2 general steps
- the heart is connected to the lungs via the pulmonary arteries and veins, which forms a pulmonary circuit
- once blood is ejected from the heart it enters the _____ whereby it is transported to other tissues in the body and eventually returns back to the heart
53
blood flow through the pulmonary circuit steps
- de-oxygenated blood is received by the RA via the superior and inferior vena cava
- 2. RA depolarizes and contracts; when atrial pressure exceeds 10 mm Hg (during contraction), the tricuspid valve opens and allows blood to flow into the RV
- 3. RV depolarizes and contracts, pressure increases to 15-25 mmHg, which closes the tricuspid valve, thereby blocking blood flow back into the RA
- the increase in pressure also opens the pulmonary valve, directing de-oxygenated blood flow to the lungs via the pulmonary arteries
- 4. after passing through the lungs, oxygenated blood is received by the LA via the pulmonary veins
54
pulmonary circuit continued
- 5. LA depolarizes and contracts. When atrial pressure exceeds 10 mmHg (during contraction) the mitral valve opens and allows blood to flow into the LV
- LV depolarizes and contracts, pressure increases to 15-25 mmHg, which closes the mitral valve, thereby blocking blood flow back into the LA. The increase in pressure also opens the aortic valve, directing oxygenated blood through the aorta and into the systemic circulation
- after passing through the systemic circulation (muscles, skin, etc.) the de-oxygenated blood is returned to the heart via the superior and inferior vena cava
55
Important Concept
| -when heart depolarization is synced correctly, which above steps should occur at the same time?
steps 2 and 5
| steps 3 and 4
56
important cardiovascular parameters
```
HR
stroke volume (SV)
ejection fraction (EF)
cardiac output (Q)
systolic blood pressure (SBP)
diastolic blood pressure (DBP)
mean arterial pressure (MAP)
total peripheral resistance (TPR)
rate pressure product
```
57
HR
- what is it?
- balance between...
- resting
- normal maximum
the number of times a heart contracts within a given time period
balance between
-sympathetic nervous system stimulation (Norepi and Epi) and parasympathetic stimulation (Ach) influence determines the "chronotropic" state, or pacing of HR
resting
-60-100 bpm
normal maximum
-200-220 bpm for college-aged student or athlete
58
storke volume
- what is it?
- SV =
- influenced by...
- resting
- normal maximum
the total amount (mL) of blood pumped out of the left ventricle each heart beat
SV = end diastolic volume (ventricular filling) - end systolic volume (ventricular emptying)
significantly influenced by total blood volume and venous return
-hydration state (better hydration = higher SV)
resting: 75 mL/beat
normal maximum: up to 150 mL/beat
59
ejection fraction
- what is it?
- EF =
- resting
- normal maximum
the relative amount (%) of blood pumped out of the left ventricle each heart beat
EF = SV/EDV x 100
resting: 50%
normal maximum: up to 70-75 %
60
Cardiac Output
- what is it?
- Q =
- huge determinant of...
- resting
- normal maximum
```
the RATE of blood flow through the heart per minute
Q = HR x SV
huge determinant of blood pressure
Resting: 5 L/min
Normal Maximum: up to 20-25 L/min
```
61
Systolic blood pressure
-what is it?
resting
normal maximum
during ventricular contraction (systole) blood fills arteries and increases the pressure exerted on the arterial walls
resting: 115-120 mmHg
normal maximum: up to 350 mmHg
62
diastolic blood pressure
-what is it?
resting
normal maximum
during ventricular relaxation (diastole) the driving force behind blood flow is dimished, so arterial pressure falls
resting: 75-80 mmHg
normal maximum: up to 250 mmHg
63
mean arterial pressure
-what is it?
MAPrest =
MAPexercise =
the pressure differential/gradient of arterial blood flow
must be about 60 mmHg to promote unidirectional flow
MAPrest = DBP + 0.33 (SBP-DBP)
MAPexercise = DBP + 0.5 (SBP-DBP)
64
Total Peripheral Resistance
- regulates
- TPR =
a main regulator of systemic blood flow
| TPR = MAP/Q
65
Rate Pressure Product
indicates
-RPP =
indicates the O2 requirements of the heart
| RPP = HR x SBP
66
the heart regulates the _____ of blood flow through the body
magnitude
67
heart performance is influenced by three main factors
preload
afterload
contractility
68
preload
- represented by
- what is it?
- Frank-Starling Law
- influenced by
```
represented by EDV
ability to return blood to heart via venous return
Frank-Starling Law
-the heart will pump the blood it receives
influenced by
-muscle pump
-respiratory pump
-abdominal muscles
-degree of venoconstriction
```
69
afterload
- represented by
- what is it?
- influenced by
```
represented by TPR and MAP
pressure the heart has to overcome to eject blood into systemic circulation; "arterial blood pressure"
influenced by
-degree of vasoconstriction
-vessel health
```
70
contractility
- what is it
- influenced by
```
strength of ventricular contraction
influenced by
-intracellular (Ca2+)
-preload/muscle stretch
-nervous innervation
```
71
systemic circulation
- regulates
- regulated by
```
regulates
-distribution
regulated by
-neural mechanisms
-metabolic conditions
```
72
neural mechanisms
| -functions
"central command center" (hypothalamus and medulla oblongata)
-sends blood where it is anticipated (feed toward system)
baroreceptors within vessels monitor blood pressure and relay that to the medulla oblongata (feedback system)
73
metabolic conditions
- location
- -examples
- promote
within muscle capillaries
-increased H+, CO2, lactate
-adenosine buildup
promote increased blood flow
74
promotes blood flow via
endothelium-derived relaxing factor (EDRFs), such as Nitric Oxide (NO)
-released from vessel walls to promote local vasodilation and increased blood flow
75
autonomic nervous system ultimately governs heart and systemic circulation via
sympathetic nervous system
parasympathetic nervous system
feedback from baro- and chemoreceptors
76
sympathetic
- general function
- specific processes
general
-drives HR, SV, and blood flow
specific
-released Norepi at sympathetic nerve endings (β1 heart receptors) to upregulate cardiac activity
-Norepi activation of α1 arterial receptors increases vasoconstriction, BP, and blood flow
77
parasympathetic
- function
- specific process
counters SNS activity via the vagus nerve
| Ach activation of cholinergic receptors downregulates cardiac function and induces arterial vasodilation
78
feedback from baro- and chemoreceptors
- in response to
- elicits
in response to localized metabolite accumulation and stress on vessel walls
elicits an appropriate SNS or PSNS response
79
SNS vs. PSNS
- rest
- exercise
rest
-balance between
exercise
-SNS activity tends to predominate
80
unique regulators of blood flow in addition to the roles played by the heart, systemic circulation, and autonomic nervous system
muscle pump
respiratory pump
exercise pressor reflex
81
muscle pump
-muscle contraction...
one-way valves...
muscle contraction compresses local veins
| one-way valves prevent venous blood from flowing backward, so blood is pushed back toward heart
82
respiratory pump
| -expansion of...
expansion of thoracic cavity decreases pressure of thoracic cavity, which facilitates venous blood return to heart
83
exercise pressor reflex
- reflexive response to muscle contraction (based on mechanoreceptor feedback) that ensures adequate blood delivery and venous return to heart
- increases BP, HR, and Q, and stimulates vasoconstriction in less active tissues to redirect blood to active tissues
84
homeostatic imbalances
```
atherosclerosis
coronary artery disease
peripheral artery disease
deep vein thrombosis
pathological ventricular hypertrophy
cardiac dysrhythmia
myocardial infarction
```
85
atherosclerosis
- what is it
- occurs when
- over time
hardening of the arteries
occurs when fat, cholesterol, and other substances build up in the walls of arteries and form hard structures
over time, these plaques can block or impede arteries throughout the body, increase blood pressure (hypertension), or cause other problems
86
coronary artery disease
- what is it
- leads to
form of atherosclerosis that involves narrowing and hardening of the coronary arteries
the narrowing or blockage of the blood vessels leads to decreased/stopped blood flow, which injures cardiac tissue
87
peripheral artery disease
- what is it
- leads to
a form of atherosclerosis that involves narrowing and hardening of the arteries that supply the legs and feet
the narrowing of the blood vessels leads to decreased local blood flow, which can injure nerves and other tissues
88
deep vein thrombosis
- what is it
- leads to
formation of a blood clot in a deep vein, commonly in the leg veins (esp. femoral and popliteal veins) or the deep veins of the pelvis
impedes local blood flow, damages vessel walls, and increases the risk of a pulmonary embolism
89
pulmonary embolism
blood clot dislodges and becomes re-lodged "upstream" in the pulmonary circuit
90
pathological ventricular hypertrophy
- what is it
- what happens
enlargement of the ventricular mass (usually in the left ventricle) in response to stress or disease, such as atherosclerosis or myocardial infarction
the greater mass reduces compliance of the ventricular wall and the inner volume of the ventricular chamber, which reduces SV so the heart has to work harder to maintain Q at rest and during activity
91
cardiac dysrhythmia
- what is it?
- -types
any condition in which there is abnormal electrical activity/conduction within the heart
-heart may be too fast or too slow
-may contract in an irregular or uncoordinated fashion
-some are life-threatening
-some impede physical function
-some are simply annoying
the root causes for each dysrhythmia are unique and varied
92
myocardial infarction
- what is it?
- most are caused by...
occurs when blood flow to a part of your heart is blocked for a long enough time that part of the heart tissue is damaged or dies due to lack of O2 (ischemia)
most heart attacks are causes by a blood clot or excessive plaque buildup that blocks one or more of the coronary arteries that delivers blood to the heart tissue
