Exam 2 Flashcards
(120 cards)
1
Q
How many chambers does the heart have and what are they called?
A
4 chambers
- 2 atria
- 2 ventricles
2
Q
what kind of system are the blood vessels in?
A
close circulatory system
3
Q
veins drain into ___
A
sinuses
4
Q
Arteries drain into ___
A
arterioles
5
Q
capillaries go into ____
A
goes into ventricles
6
Q
description of blood
A
- type of connective tissue consisting of plasma
- cells & plasma
- red blood cells aren’t actual cell but are pieces of bone marrow
7
Q
what do two sets of heart valves ensure?
A
one-way flow
8
Q
AV valves description
A
- stands for atrioventricular valves
- makes sure it goes from atria to ventricle without this being reversed
9
Q
tricuspid valve
A
AV valve on the right
10
Q
Bicuspid valve
A
AV valve AKA mitral valve on the left side
11
Q
semilunar valves
A
- between ventricles & arteries
- Aortic valve
- pulmonary valve
12
Q
Aortic valve
A
left ventricle and aorta
13
Q
pulmonary valve
A
right ventricle and pulmonary trunk
14
Q
steps to blood flow in heart (basic)
A
- deoxygenated blood enters through vena cava (superior & inferior) into the right atria
- blood flows from the atria into the ventricle
- blood flows from the ventricle out the pulmonary semilunar valve and out of the heart in the pulmonary space
- the blood will come back to the heart via pulmonary veins into the left atria
- blood will flow to the left atria then to the left ventricle
- the blood will exit the heart via aortic valve, and flow through the rest of the body.
15
Q
myocardium
A
cardiac muscle that forms the walls of chambers
- allows for contraction and pressure
16
Q
types of contraction
A
- isovolumic
- systole
17
Q
types of relaxation
A
- isovolumic
- diastole
18
Q
isovolumic contraction
A
increases in pressure, but not enough to move blood
19
Q
systole contraction
A
blood in squeezed out of chamber
20
Q
isovolumic relaxation
A
decrease in pressure, but not enough to move blood
21
Q
diastole relaxation
A
blood fills a chamber
22
Q
The cardiac cycle
A
- late diastole
- atrial systole
- isovolumic contraction
- ventricular systole, atrial diastole
- isovolumic relaxation
23
Q
late diastole
A
-AV valves are open, semilunar valves are closed and myocardium is relaxed
- fills about 70% of the way
24
Q
atrial systole
A
AV valves are already open and atria will squeeze their blood into ventricles
25
Isovolumic ventricular contraction
AV valves close and there is still no movement of blood since there is not enough pressure to open semilunar valves
26
ventricular systole
Semilunar valves are now open with enough pressure and blood begins to flow out
27
isovolumic ventricular relaxation
as pressure falls, blood will begin to flow back into the atria, yet the AV valve will still be closed.
28
Auscultation
listening to the heart through the chest wall through a stethoscope
29
what is the first heart sound of the heart and what does it mean?
- "lub"
- vibrations following closure of the AV valves
30
what is the second heart sound of the heart and what does it mean?
- "dub"
- vibrations created by closing of semilunar valves
31
myogenic
- coming from the heart
- nervous system doesn't have to tell the heart to contract
- nervous system can modify heart rate
32
what can specialized cardiac muscle cells do?
- spontaneously depolarize and make pacemakers
- spontaneously sends out action potentials at a very predictable rate
33
sinoatrial node
- acts as pacemaker
- known as SA node
- sits between venous sinus and right atrium
- depolarizes atrial wall
- sets heart rate to 70 bpm
- has gap junctions
- could contribute to physical condition
34
transmit depolarization to muscle fibers via ____
electrical synapse
35
Atrioventricular node
- found only on right side of the heart
- routes the direction of electrical signals so the heart contracts from apex to base with a 0.5 sec delay
- act as pace maker at 50 bpm
36
bundle branches
- wall between two ventricles
- rapidly transmit signal to apex so depolarization is bottom up for ventricles
- acts as pacemaker at 20-40 bpm
37
Purkinje fibers
- rapidly transmit signals up the walls of the ventricles
- help spread faster
38
what would happen if perkinje fibers worked as a pacemaker?
- you will die do to the heart beating too slow
39
what are the two abbreviations for an electrocardiogram
EKG or ECG
40
Electrocardiogram
records of electrical activity at the heart
41
P-wave
- atrial depolarization
42
P-R segment
conduction through AV node and AV bundle
43
QRS complex
ventricular depolarization
44
T wave
ventricular repolarization
- can go upside down, big, or small and still be normal
- if it has a sharp peak, it may be a warning of a heart attack
45
QT interval
- strong enough physical shock during this interval can stop the heart
- ex. if it hit the heart during this interval, the heart could stop.
46
QT interval syndrome
makes this interval last longer causing it to be more dangerous
47
cardiac output
volume of blood pumped by one ventricle in a given period of time
- Avg= 5 L/min
48
cardiac output equation
CO=HR*SV
49
Stroke volume
- amount of blood pumped by one ventricle during a contraction
- avg= 70mL
50
stroke volume equation
SV=EDV-ESV
51
how can cardiac output be controlled?
change HR, SV, or both
52
cardiovascular control via parasympathetic
-Efferent path: parasympathetic neurons acetylcholine
- effector: Muscarinic receptors of autorythmic cells
- tissue response: K+ increase & Ca2+ decreased, hyperpolarizes cell and decreases rate of depolarization, heart rate goes down
53
cardiovascular control via sympathetic
- efferent path: sympathetic neurons norepinephrine
- effector: beta receptors of auto rhythmic cells
- tissue response: increase of Na+ & Ca2+ influx, increase in rate of depolarization, increased heart rate
54
parasympathetic funny channels
will take more of hyper polarization to opens later and are less active.
55
sympathetic funny channels
open earlier and more active.
- slope will be sharper as ions move in faster and it doesn't take as much to open the channels
56
force of contraction is affected by ____
- length of muscle fiber
- number of active cross-bridges
- contractility of heart
- as stretch of the ventricular wall increases, so does stroke volume
- preload
57
length of muscle fiber is determined by what?
determined by volume of blood at the beginning of contraction
58
contractility increases with what?
- more ATP
- more calcium
- if troponin is more efficient at moving tropomyosin
59
the more stretched out the ventricular wall is, what happens?
this means there is more blood so the harder the force of contraction is, increasing movement of blood by more than double.
60
Frank-Starling law states what?
- stroke volume increases as EDV increases
- the heart becomes more efficient at moving blood
61
What determines EDV?
venous return
62
Venous return is affected by what?
- skeletal muscle pump
- respiratory pump
- sympathetic innervation of veins
63
when you move, what happens to blood?
- the more you move around, the more blood vessels shoot blood up to the heart and valves close, so blood doesn't come back down.
64
what will hyperventilation do to the veins?
cause thoracic veins to squeeze blood towards the heart
65
describe heart rate in your sleep
in sleep, heart rate and rate of breathing decrease so that energy can be used towards:
- tissue repair
- hormone regulation
- growth
66
sympathetic vasocontriction
a process in which the sympathetic nervous system triggers the narrowing of blood vessels, reducing blood flow
67
what is the blood flow down a pressure gradient?
moves from high to low pressure (blood will go to the path of least resistance so it will always go towards low pressure)
68
what is driving pressure created by?
ventricles
69
what kind of flow do arteries have?
experience high, fluctuating pressures and fast flow rate
70
what kind of flow do capillaries have?
experience lower pressure and very slow flow rates
- increase surface area
- more capillary blood than anything else in the body causing flow to be slow
71
what kind of flow do veins have?
experience lowest pressure, but flow rates increase due to reduced total surface area
72
pressure cascade
higher in arteries and lower in veins
73
smooth muscle
provides resistance to expansion and allows for control of flow rate
74
elastic tissue
provides resistance to expansion
- allows it to exist stretching
75
fibrous tissue
holds shape at a cost of control of rate
- prevents from being pinched off and closed
76
Why is cardiac muscle not capable of tetanus?
tetanus has a long refractory period. if this were to occur in the heart, then you would die.
77
How is cardiac muscle action potential different than skeletal?
cardiac: potentials are long, calcium ion are responsible for initial depolarization phase.
Skeletal: Potentials are short, sodium channels are responsible for initial depolarization phase
78
What is cardiac output? what components of physiology determine cardiac output?
The amount of blood the heart pumps out in one minute.
- components that determine this are heart rate and stroke volume
79
How is heart rate controlled via sympathetic and parasympathetic signals? list all neurotransmitters, receptors, and effects.
SNS
- neurotransmitter: releases norepinephrine and epinephrine
- receptor: beta-1 adrenergic receptors on the heart muscle
- effect: increases heart rate, force of contraction, and conduction velocity in the heart. muscles
PNS
- neurotransmitter: acetylcholine
- receptor: Muscarinic M2 receptors on the heart muscle
- effect: decreases heart rate
80
How is stroke volume controlled?
- preload
- contractility
- afterload
81
What blood vessels experience the highest pressures? lowest? how does the structure of the vessel match its function?
- Arteries experience highest blood pressure. it has direct connection to the heart. it is thicker and has more elasticity
- Veins experience lowest blood pressure as they return blood to the heart. it is thinner and has more distensible walls
82
How are resistance and vessel diameter related? what does this mean for pressure and flow rates through vessels?
a wider vessel means less friction and lower resistance, increasing flow, while narrower vessel leads to increased friction and resistance, decreasing flow.
- to maintain blood flow, the heart must generate a pressure gradient to overcome resistance
- a decrease in vessel diameter will decrease blood flow, and vise versa
83
How can blood be shunted away from a capillary bed?
blood can be shunted away from capillary bed by closing the precapillary sphincters
84
What is the purpose of valves in large veins?
ensure one way blood flow toward the heart, preventing back flow and pooling
85
How is blood pressure measured? mean arterial pressure?
- auscultation
OR
- sphygmomanometer
86
How is blood pressure/flow controlled?
- changes in cardiac output
- changes in blood vessel diameter
- sphincters
87
How do substances move out of the blood and into tissues?
through diffusion
88
diffusion definition
molecules move from areas of high concentration to areas of low concentration through capillary walls.
89
describe myogenic auto regulation
happen because the muscle itself is changing pressure.
90
how do we dilate arteriole diameter?
- decrease norepinephrine release onto alpha receptors.
- as the signal rate decreases, the blood vessels dilate.
91
how do we constrict arteriole diameter?
- increase the amount of norepinephrine release onto alpha receptors.
- as signal rate increases, the blood vessel constricts.
92
what experiences the highest pressures as they are closest to the heart?
Arteries
93
how many layers does the artery wall have and what are they?
4
- endothelium
- elastic tissue
- smooth tissue
- fibrous tissue
94
how many layers does the arteriole wall have and what are they?
2
- endothelium
- smooth muscle
95
how many layers does the capillary wall have and what are they?
1
- endothelium
96
how many layers does the venule wall have and what are they?
2
- endothelium
- fibrous tissue
97
how many layers does the vein wall have and what are they?
4
- endothelium
- fibrous tissue
- smooth muscle
- elastic tissue
98
veins in the lower legs
- have very low pressure
- we have to fight gravity to get blood pumped back to the heart
- when skeletal muscle contracts around the vein, blood will be squeezed up and valves will close behind it to stop from going back down.
- this process will repeat till it reaches the heart
99
what causes deep vein throbmosis?
standing or sitting upright for long periods of time without moving.
- edema will occur and blood clot may form
100
vasoconstriction
a decrease in blood vessel diameter and radius
- decreases blood flow
- increases pressure, velocity
101
vasodilation
an increase in blood vessel diameter/radius
- increase blood flow
- decrease pressure, velocity
102
If trying to reduce amount of blood flow to a capillary, what do we have to do?
- we have to reduce the size of the arteriole before
OR
- bypass by using pre-capillary sphincters and a shunt called anastomosis
103
Systolic
highest pressure and rest at the end of ventricular systole
104
Diastolic
lowest pressure at rest at the end of ventricular diastole
105
how to calculate pulse pressure
systolic pressure-diastolic pressure
106
how to calculate mean arterial pressure
Diastolic+ 1/3 (pulse pressure)
107
what is mean arterial blood pressure determined by?
- Blood volume
- cardiac output
- system resistance to blood flow
- venoconstriction
108
myogenic auto regulation
happen because the muscle itself is changing pressure
109
paracrine
active hyperemia vs reactive hyperemia
110
hyperemia
increased blood flow to tissue
111
hormones involved in control of blood pressure
vasopressin
112
Active hyperemia
- matches blood flow to increase metabolism
- Release of metabolic vasodilators into ECF and arterioles.
- Arteriole dilate
- Decreased resistance creates increase in blood flow
- O2 and nutrient supply to tissue increases as long as metabolism is increased.
113
reactive hyperemia
follows a period of decreased blood flow
114
____ & ____ exchange materials across thin capillary walls
- plasma
- cells
115
what is related to metabolic activity of cells and why?
capillary density
- more density, more metabolic activity of cells
116
what blood vessel has the thinnest walls? and what are they made up of?
capillaries; single layer of flattened endothelial cells
117
exchange between plasma and interstitial fluid occurs by what 2 processes?
- para-cellular pathway
- endothelial transport
118
what are small dissolved solutes and gases moved by?
diffusion down concentration gradient
119
what are large solutes and proteins moved by?
vesicular transport (transocytosis)
120
Why aren't fenestrations always good?
if pressure increases too much, they leak
