the cardiovascular system Flashcards
1
Q
what are the three main components that make up the cardiovascular system
A
the heart, the vessels, and the blood
2
Q
what does the heart do
A
it is a muscle that constantly contracts to pump blood throughout the body
3
Q
what do the blood vessels do?
A
provide a pathway for the blood to travel
4
Q
what is the blood
A
a fluid that transports oxygen and nutrients needed to cells and carbon dioxide waste away from cells
5
Q
how much blood does the heart pump, on average
A
7000 liters of blood
6
Q
how big is an adult heart?
A
14 cm long and 9 cm wide
7
Q
where is the heart located?
A
the middle of the thoracic cavity and bordered by the lobes of the lungs
8
Q
how is the heart structured?
A
4 hollow chambers that pump and receive blood
9
Q
which chambers do what?
A
the upper chambers are the left and right atrium and receive the blood
the lower chambers are the left and right ventricles which pump the blood
10
Q
why are the chambers separated from each other?
A
to ensure unidirectional blood flow
11
Q
what separates the atriums and the ventricles?
A
a thin muscular wall called a septum
12
Q
what does the septum do?
A
ensures that the blood in the right side of the heart does not mix with the blood on the left side
13
Q
which sides contain oxygenated blood and which do not?
A
right side contains poorly oxygenated and left contains oxygenated
14
Q
what separates the atria from the ventricles?
A
connective tissues called valves
15
Q
what is the purpose of the valves?
A
ensures that the blood travels in one direction from the atria to the ventricles and not the other way around
16
Q
what is the heart connected to?
A
several large blood vessels
17
Q
how does the blood flow through the heart?
A
deoxygenated blood reaches the right atrium through 2 large blood vessels
18
Q
what are the names of the 2 large blood vessels that connect to the right atrium
A
superior vena cava and inferior vena cava
19
Q
where is the tricuspid valve located?
A
between the right atrium and the right ventricle
20
Q
what happens when the tricuspid valve is open?
A
blood travels from the right atrium to the right ventricle
21
Q
what happens when the tricuspid valve contracts?
A
the blood is ejected through the pulmonary semilunar valve to the pulmonary trunk
22
Q
what is the pulmonary trunk?
A
a large blood vessel that delivers blood to the lung
23
Q
what happens when blood reaches the lung?
A
the blood picks up oxygen and unloads carbon dioxide and the pulmonary veins return it to the left atrium
24
Q
where is the bicuspid valve?
A
borders the left atrium and the left ventricle
25
what happens when the bicuspid valve opens
the blood goes into the left ventricle
26
what part of the heart has the thickest muscle wall and the strongest force of contraction?
the left ventricle
27
what happens when the left ventricle contracts?
the blood travels through the aortic semilunar valve to the aorta
28
what is the largest blood vessel in the body and what does it do?
the aorta and it delivers blood to all body cells
29
what happens when blood reaches the body cells?
unloads oxygen and picks up carbon dioxide and is now deoxygenated
30
how does the deoxygenated blood return to the heart
via the superior and inferior vena cava
31
what order do heart contractions happen?
the atria contract simultaniously and then the ventricles contract simultaneously (recieves blood first and then ejects the blood)
32
how does the heart get nourishment?
not through the blood passing through it; but through a separate blood circulation
33
what is the heart's blood circulation system called?
the coronary system
34
how is the coronary system structured?
the right and left coronary arteries branch from the aorta and supply the right and left side of the heart, respectively
35
what happens regarding the coronary arteries when the ventricles are in the relaxed state
both coronary blood vessels supply the heart tissue
36
what is one of the major branches of the coronary system and what does it support?
the anterior interventricular artery (left anterior descending or LAD); supports front of heart
37
what are anastomases
alternate pathways for blood delivery
38
when do anastomases become important
when major blood vessels are blocked due to coronary artery disease (CAD)
39
what is the relaxtion of the heart referred to as?
diastole
40
what is the contraction of the heart referred to as?
systole
41
what is a cardiac cycle
a heartbeat or the complete cycle of contraction and relaxation of the chambers
42
what is the heart sound through a stethoscope termed and why
the lub-dup and it results from the valves closing
43
when does the lub occur?
during ventricular contraction when the tricuspid and bicuspid valves close
44
when does the dup occur?
when the ventricles are relaxed during the period when the aortic and semilunar valves are closing
45
what happens if the valves are not closing properly?
blood may leak from the atria to the ventricle (a heart murmer)
46
what is blood pressure
the force that blood exerts on the walls of the blood vessels as it passes through
47
where is the blood pressure that is measured in a docs office measured from?
the aorta
48
what happens in the aorta as the ventricles contract
blood pressure increases (systolic)
49
what happens in the aorta as the ventricles relax
blood pressure decreases (diastolic)
50
what is the device used to measure blood pressure called?
sphygmomanometer
51
where can you feel the blood pressure changing with your hands?
by touching the radial artery on your arm or on the carotid artery on the neck
52
what is the cardiac conduction system
the specialized muscle cells that distribute electrical impules throughout the heart to ensure constant contraction
53
what is the average resting HR in healthy individuals
70-100 bpm
54
what determines the amount of blood that can enter the arteries
the heart contraction strength
55
what is stroke volume (SV)
the amount of blood ejected from the heart per beat
56
what is cardiac output
the amount of blood ejected per minute
57
how to calculate cardiac output
HR x stroke volume
58
what do blood vessels do?
they nourish the body with blood in a closed circuit of tubes that take blood away from the heart and then back to the heart
59
what are different kinds of blood vessels?
arteries, arterioles, capillaries, venules, and veins
60
how long would the blood vessels stretch if all connected together?
62 000 miles
61
which blood vessels nourish the body cells?
the arteries
62
how many layers make up an artery
3
63
what are the 3 layers of an artery called? {in order from outermost to innermost}
tunica externa, the tunica media, and the tunica intima
64
what is the tunica externa made of
the outermost layer of an made of a thick layer of connective tissue
65
what does the tunica externa do?
provides protection and elasticity to to allow the blood vessel to to stretch and increase in diameter when needed
66
what is the tunica media made of
the middle layer of an artery made of smooth muscle
67
what is the tunica media'a function?
to modulate the diameter of the blood vessel
68
what is vasodilation
when the tunica media smooth muscles relax and widen the lumen of the blood vessel
69
what is vasoconstriction
when the tunica media's smooth muscles contract and decrease the diameter of the blood vessel
70
what is smooth muscle
an involuntary muscle
71
what is the tunica intima?
the innermost layer of an artery made of a single layer of endothelial cells
72
where do problem start inside a blood vessel?
the endothelial cells
73
what is the lumen?
the hole/cavity is the blood vessel
74
which layer is in contact with the blood flowing?
the tunica intima
75
how to characterize a healthy blood vessel?
flexible with healthy endothelial cells
76
what is released from the endothelial cells and what does it do?
nitric acid, a potent vasodilator
77
what do endothelial cells do?
control vasodilation and vasoconstriction
78
what is blood and its components?
a connective tissue made of cells, water, and proteins
79
what is the function of blood?
vital - carrying oxygen, nutrients, hormones, and other chemicals to cells to cells as well as picking up their metabolic waste products and taking them away
80
average amount of blood in the body
male: 5-6 L
female: 4-5 L
81
what type of cells are in the blood?
red blood cells (erythrocytes), white blood cells, and cell fragments aka platelets
82
what do red blood cells do?
carry oxygen and carbon dioxide
83
what do white blood cells do?
function in immunity
84
what do platelets do
function in clot formation
85
what is blood plasma?
the water and protein portion of blood
86
what is the purpose of a hemtocrit (aka packed cell volume)?
to assess the proportions of various components of the blood
87
how to perform a hematocrit?
centrifuge a blood sample to see the different components of the blood based on density
88
what happens to red blood cells during a hematocrit?
settle at the bottom of the tube and represent a large quantity
89
what happens to white blood cells and platelets during a hematocrit?
they settle in the middle
90
what happens to the plasma during a hematocrit?
forms a large clear portion at the top
91
what is the result hematocrit?
the percentage of red blood cells that settle at the bottom of the test tube to the total volume of the blood sample
92
what is the hematocrit in a healthy male?
42-47%
93
what happens during a heart attack?
an artery isn't functioning properly so there is deprivation of blood to some heart cells and they can die off; artery is closed off
94
what can cause heart attacks?
fat build up in blood vessels as a result of over consumption of fats and calories in general over time
95
signs of fat build up in arteries
shortness of breath because less blood can get through the arteries to supply the body
96
what is it called when an artery connected to the brain closes up?
stroke
97
what arteries tend to close up first?
1st: coronary arteries
2nd: brain
3rd: others
98
what is cholesterol
a form of lipid that exists in our body
99
2 sources of cholesterol
exogenous - dietary
| endogenous - synthesized in the liver
100
do we need to ingest cholesterol?
NO! our body can synthesize it
101
how is ingested cholesterol digested?
in the small intestine by the pancreatic enzyme cholesterol esterase
102
what happens to cholesterol after digestion by the pancreatic enzyme?
transported in micelles into the enterocytes in the lumen of the duodendum
103
what happens to cholesterol after transport into the enterocytes
packaged into chylomicrons
104
what is a chylomicron?
a large lipoprotein vesicle
105
what do the chylomicrons do
cross the enterocytes into the lymphatic system before reaching the blood cells and take the cholesterol to be stored in the liver
106
how does the liver function with cholesterol
acts as a hub for storage and release of cholesterol
107
how does the liver send cholesterol into circulation
packaging it in very low-density lipoprotein vesicles (VLDL)
108
what do VLDLs do?
travel in circulation and unload lipid products to the body cells
109
what happens to VLDLs as their lipid content decreases?
they transform into low-density lipoproteins (LDLs) and are returned to the liver where the lipid contents canbe recycled
110
what are HDLs and where are they produced
high density lipoprotein vesicles and are produced by the liver
111
what do HDLs do?
collect excess cholesterol from the blood and return it to the liver
112
why is LDL bad?
carries a high amount of cholesterol and has the potential to get stuck in the blood vessels, leading to cardiovascular disease
113
why is HDL good?
collects cholesterol from the blood and returns it to the liver for excretion
114
what is athlerosclerosis?
a disease of the arteries that is the primary cause of myocardial infarctions (progressive) and strokes
115
how does athlerosclerosis start?
a build up of cholesterol that is traveling in lipoprotein vesicles in the blood vessels and once it's trapped, it starts to oxidize
116
why is it bad for cholesterol to oxidize?
it results in inflamation and recruitment of immune cells which can damage the blood vessel until blood flow starts to diminish
117
why is diminishing blood flow bad?
the cells are deprived of oxygen and cells of vital organs start to undergo ischemia (cell death)
118
what ultimately leads to a stroke or heart attack?
thrombus (clot) formation that completely blocks blood flow to the heart and/or brain
119
endothelial layer function
selective permiable layer to facilitate the movement of blood contents across it
120
other functions of endothelial cells
regulating blood flow, regenerating, and communicating with immune cells, control the overlaying smooth muscle cels in the tunica media
121
what is a major stimulus of endothelial cells?
shear stress induced as blood flows through the vessel
122
what is a common site for athlerosclerosis?
endothelial cells in regions where the arteries branch
123
what can lead to an increased circulation of cholesterol in LDLs?
high fat diets
124
how does LDL buildup relate to endothelial cells?
the LDL starts to permeate through the endothelial layer and and build up in the sub-endothelial space between the tunica intima and the tunica media
125
how does HDL interact with the negative effects of LDLs
it minimizes them
126
what happens during the Inflammation stage of athlerosclerosis?
characetrized by recruitment of immune cells such as macrophages and lymphocytes, to the site of the LDL buildup
127
what happens when macrophages reach the site where LDL is trapped during the foam-cell formation stage of athlerosclerosis?
they roll and enter through the space between the endothelial cells into the sub-endothelial cells
128
what is the main function of the immune cells during the foam-cell foration stage of athlerosclerosis?
to clear the trapped lipid by uptaking them and clearing them out of the subendothelial space
129
what is endocytosis?
a mechanism where macrophages bind and engulf trapped LDL
130
why is the stage called foam-cell stage?
the macrophages enlarge in size as fat deposits grow and become foamy cells and yellow-ish
131
what happens in the fibrous plaques formation stage of athlerosclerosis?
the macrophages and leukocytes in the subendothelial space release more cytokins
132
what are cytokins?
chemicals that promote the formation of aggregates known as plaques
133
what are plaques?
lipid filled masses that combine with migrating smooth muscle cells
134
why does the blood vessel lose flexibility?
fibers and calcium are depositied to stabilize the border of the plaque-mass
135
clinical term to describe percent blood vessel oclusion
stenosis
136
what is a coronary artery bypass graft (CABG)
when a blood vessel is sewn so the blood flow is bypassed around the area of occlusion
137
what is ischemia
scar tissue formation
138
what are 2 cases for a heat attack to occur
1. the amount of scar tissue and dead cells block the blood flow to a large proportion of the heart, leading it to underperform
2. the plaque that has formed in the blood vessel is unstable and may get washed out in the circulation where it reaches a smaller blood vessel and completely occludes it
139
diagnosis start of athlerosclerosis
shortness of breath, tingling sensation, pain, numbness is the left arm or chest area
140
what will a doc say if stenosis is low
give medication to lower cholesterol and to exercise and eat a low fat diet
141
what will a doc say if stenosis is high
admit patient to hospital and given surgery/procedural options to remove plaque
142
what is angioplasty
a technique to widen a blood vessel at the site of occlusion using a stent and balloon inserted through the femoral artery on the leg to the site of the narrowing
143
what is a coronary artery bypass graft
a surgical procedure where arteries or veins from other locations in the body are removed and placed around the area of the blockage so blood bypasses the blockage
144
what are common arteries/veins used for a graft
the internal thoracic artery that supplies the arm, and the greater saphenous vein that drains the leg
145
risk factors of cardiovascular disease [9]
sedentary lifestyle
not exercising regularly
consuming lots of alcohol
not consuming recommended amounts of omega 3 and omega 6 fatty acids
not consuming a variety of fruits and vegetables
smoking
consuming a diet high in saturated fats and trans fats
being overweight or obese
prolonged inflamation
