Exam 11: April 3-7 Flashcards
1
Q
what is a P wave?
A
atrial depolarization part of EKG
2
Q
what is a QRS complex?
A
ventricular depolarization part of EKG
obscures atrial repolarization
3
Q
what is a T wave?
A
ventricular repolarization
4
Q
what sound should your heart make?
A
lub dub
5
Q
when does the lub sound happen? what is it?
A
happens right after QRS complex
it’s the cuspids closing
6
Q
what is the dub sound? when does it happen?
A
happens right after T wave
it’s the semilunars closing
7
Q
what causes the heart to squeeze?
A
squeeze is happening by myocardial cells squeezing
it’s no different than squeezing/contraction of skeletal muscle biceps so your heart doesn’t make any sounds either
8
Q
what is the cause of the sound of your heart beat?
A
it’s the one way valves
when you get a big force to slam a door you get a big sound
9
Q
what is happening during the QRS complex?
A
QRS is the squeeze of ventricles
we don’t want the blood to go back into the atria so the tricuspid and bicuspid valves close
(when ventricles squeeze you want the blood to go from LV to aorta – in our RV you want the blood to go to pulmonary artery)
10
Q
what happens in the left ventricle during QRS complex?
A
when ventricles squeeze you want the blood to go from LV to aorta
11
Q
what happens in the right ventricle during QRS complex?
A
in our RV you want the blood to go to pulmonary artery
12
Q
what happens during the t wave?
A
it’s the relaxation of ventricles so the blood is in the aorta, in the pulmonary artery
you want the blood to continue on to the body so the semilunar valve closes
13
Q
what does it mean if your heart has a murmur?
A
you don’t want to heard a shh/murmur when listening to the heart because that means the valves aren’t closing properly and you’re getting backflow happening = murmur
14
Q
what does lub shh dub mean?
A
it means blood is going back into atria so it’s a problem with cuspid
15
Q
what does lub dub shh mean?
A
problem with semilunar valve
16
Q
how do things move with respect to pressure?
A
things move from high to low pressure
we create convective flow because we can’t rely on diffusion
17
Q
what causes blood pressure?
A
BP is due to space contraction
the heart does a 3D squeeze
atria gets squeeze to go down while ventricles get squeeze to go up so you can direct pressure in whatever way it needs to go
18
Q
what’s the relationship between P and V?
A
PV = nRT
we want to change the volume of the space so pressure has to change too
P = (nRT)/V = c/V so you have an inverse relationship between P and V
as volume gets smaller, pressure increases
19
Q
what are the two phases in a stroke?
A
systole and disatole
20
Q
what is the systole phase?
A
contraction to empty/send blood out
1/3 of the time
21
Q
what is the diastole phase?
A
relaxation to fill
2/3 of the time
22
Q
what is a stroke?
A
it’s one cycle
one systolic and one diastolic phase
23
Q
what is the end diastolic volume?
A
pre-contraction
24
Q
what is end systolic volume?
A
post-contraction
she dumped water on the stage
25
how do you know how much blood gets pumped out of the heart each stroke?
end diastolic - end systolic
take the maximum volume of end diastolic - minimum volume at the end of the squeeze which is end systolic
blood goes out into your vessels and mingles with the rest of the blood in your body so you can’t tell how much left but you can tell how much blood was in the heart before and after contraction and you can take the difference between the two
26
what is the maximum volume of the heart?
135 mL
end diastolic volume
27
what is the minimum volume of the heart?
65 mL
end systolic volume
28
what is stroke volume?
how much you get out of the heart in one stroke
SV
29
what is heart rate?
strokes per minute
or
cycles per minute
HR
30
what is the formula for cardiac output?
multiple stroke volume x number of times you do that process
SV x HR
31
what is cardiac output?
SV x HR
the overall amount that gets dumped out is a combination of how much is going out and how many times did you do it
4.9 L /minute which is pretty efficient even though only half of blood leaves every time you pump
32
what are the two ways to regulate cardiac output?
heart rate or stroke volume
or
EDV or ESV
33
what happens to SV if you change HR?
they're relatively independent
you can regulate those two things separate of each other
you can keep HR the same and change SV up or down or vice versa
34
what impacts heart rate?
1) autonomic nervous system
2) epinephrine
3) body temperature
4) electrolytes
5) endocrines
35
what controls heart rate?
autonomic nervous system
we have a base line of 70 bpm but SNV will make it higher while PNS will make it lower
36
how does the autonomic nervous system impact heart rate?
1) ANS can give input to SA nodded increase or decrease heart rate
SNS will increase HR
PNS will decrease HR
2) ANS can also change conduction velocity
37
how does the autonomic nervous system change conduction velocity?
if we get things moving faster, and have atrial cells pass signals on faster then we can shorten the amount of time it takes to do a cycle so that the HR can go up
need to increase AP frequency to do this
38
how does epinephrine impact heart rate?
epinephrine put in by SNV gets cardiac output to go up by impacting HR
this is why you use epi in the ER room if someone’s heart isn’t working right
39
how does body temperature impact heart rate?
if you get too high or low of temperature, the HR will increase in both cases
there is a dive reflex though when you get too low of a temperature then your body will drop your HR
40
how do electrolytes impact heart rate?
HR depends on AP so you need Na and K for AP to work
41
how do endocrines impact heart rate?
when we fall in love your heart pitter patters”
especially happens with sex endocrines
42
in what ways can you regulate stroke volume?
1) increase end diastolic volume
2) arterial pressure
3) sympathetic nervous system
43
how does increasing end diastolic volume effect stroke volume?
end diastolic volume = largest volume because it’s the end of the relaxation
aka how much you fill the heart up
if the EDV is bigger you get an increased contraction force when stretched a little
filling the heart a little more gets us a better contraction
stretching increases potential for CBC
44
what happens if the end diastolic volume is increased too much?
you stretch your skeletal muscles before you exercise because you need myosin and actin to pull against each other
when you stretch you make sure they line up again so what you see when you do stretch of the heart, you stretch myocardial cells and straighten out myosin/actin
you can’t stretch too much because then you’ll separate myosin and actin and if that happens, there’s not CBC
45
what happens to ESV if EDV increases?
SV = EDV - ESV
increasing EDV means ESV decreases
both of these helps SV to be bigger
46
what is congestive heart failure?
when your heart is stretched too far and then their CBC doesn’t work
decreased force when too much stretch though because that’ll eliminate CBC
we want to fill heart a little bit more but not too much because then we’ll get rid of CBC – you hit a threshold basically
47
can your heart recover from over stretching/having too high of EDV?
yes
you can’t so easily relax your heart and let it be able to recover if you over stretch it
but now we’re figuring out that you just have to give it enough time off so that all its proteins can realign
48
what did avalon do during lecture?
she demonstrated arterial pressure by pushing a chair with bronson in it
49
what is arterial pressure?
heart moves the blood out
the heart moves blood out by creating pressure
more pressure in the arteries means the heart has more to push against which is harder for it
if there’s too much pressure outside of the heart, the heart won’t be able to do its job
50
what do the ventricles do with blood? what does it make?
they eject blood into arteries
there’s a pressure gradient that we have to create enough pressure in the heart that’s bigger than the pressure gradient in the arteries so that we can send the blood out
pressure gradient in arteries creates resistance
51
what does increased arterial pressure do to stroke volume?
there will be no change in EDV but ESV will increase
this means that overall, SV decreases because we'll have more blood left in the heart
52
what effect does the sympathetic nervous system have on stroke volume?
NE/Epi from SNV causes a better squeeze regardless of starting EDV = will increase contraction force regardless of EDV
if you squeeze better you get smaller ESV which means bigger SV
53
what are all blood vessels lined with?
endothelial cells
54
what do endothelial cells do?
endothelial cells like all blood vessels
they act as separation between plasma and interstitial fluid compartments
55
what do arteries do?
they carry blood away from the heart
do NOT say they always carry oxygenated blood because the pulmonary artery carrier deoxygenated blood
56
why are arteries elastic?
you need flexibility/elasticity of arteries to get continuous flow
we need arteries to be elastic so that they give when a big amount of blood comes from the heart and recover when the heart isn’t doing anything so that there’s a continuous flow rather than flow/no flow throughout a heart beat
during no flow the cells don’t get oxygen or glucose so you want a continuous flow
57
what's wrapped around arteries? what does it do?
smooth muscle
smooth muscles does not to participate in elasticity component but rather adjusting the size of the vessel which comes into play with PV=nRT to change blood pressure coming through vessels
58
how much hydrostatic pressure do arteries have?
arties have the highest level of hydrostatic pressure of any of our vessels!
59
what is blood pressure?
the amount of flow
the amount of convective flow to push blood out to the body
60
what is hydrostatic pressure?
vessels are needed to control movement of fluid because fluid doesn’t always want to go in the path that it does and the fluid pushes against the walls of the vessels aka hydrostatic pressure
body gets blood in the systolic phase of the blood and the walls need to expand because of the hydrostatic pressure pushing against them
61
when does the body get blood? what effect does this have on hydrostatic pressure in vessels?
body gets blood in the systolic phase of the blood and the walls need to expand because of the hydrostatic pressure pushing against them
62
what's the relationship between blood pressure and hydrostatic pressure?
direct relationship
the bigger the blood pressure the bigger the hydrostatic pressure
63
how can you lower hydrostatic pressure?
the more surface area for the vessel wall, the lower the hydrostatic pressure
we are putting this pressure against walls, we’re putting the pressure against a space so the more we disperse this pressure against a particular area=the lower the ending force will be
we would rather be stepped on with elephant with big feet rather than high heel
depends on how much wall it is pushing on
we are putting this pressure against space, so the more space=bigger dispersion= the lower the ending force will be
64
what two things factor into hydrostatic pressure?
blood pressure and surface area of vessel
65
why do we have really high hydrostatic pressure within our arteries?
because we have very high blood pressure because we’re right by the source that’s causing BP (heart) and we don’t have a lot of arties to spread the pressure over
aka high blood pressure and low surface area
66
what are arterioles?
they're much smaller vessels than arteries
they're also much further away from our heart
67
how elastic are arterioles? why?
less elastic than arteries
they just need to make small changes in these variations in pressure since your arteries already took care of the big variation from your heart
68
what surrounds arterioles? what does it do?
smooth muscle
to change size of the vessel and change blood pressure
69
what hydrostatic pressure do arterioles have? why?
high but not as high as the arteries because they're farther from the heart
as you get farther from the source generating the pressure, our BP which factors into hydrostatic pressure, is going down so therefore the hydrostatic pressure is also going down
70
what is the smallest vessel?
capillaries
71
what is the size capacity of capillaries?
only one RBC can move through them at a time!
the RBC actually has to turn sideways and squeeze through there so it's not a simple movement
aka these capillaries are really small!!
72
where do you do exchange in your body?
capillaries are where you do exchange between interstitial fluid and plasma
arteries and arterioles don't do exchange
73
why do you want capillaries to be small?
you want the capillaries to be small and abide by size of RBC because RBC carry oxygen and you want them to be right there to deliver oxygen
74
how many layers do capillaries have?
they only have one layer and that layer is made up of just endothelial cells
it's endothelial cells because all vessels have endothelial cells
75
why do capillaries have thin walls?
capillaries have very thin walls with only one layer so that this way things can diffuse despite their distance problem
if the walls are thin, the walls are thin and diffusion is easy
BP creates convection to help diffusion and in the end it’s still diffusion because at the end the oxygen still needs to diffuse from plasma to interstitial fluid
76
why do we need diffusion in our circulatory system? where does it happen?
oxygen diffuse from plasma to IF, the glucose from the plasma to IF via capillaries
if we started making these walls thicker we would have more difficulty making diffusion happen
77
how big is the surface area of capillaries?
capillaries are the exchange site aka where diffusion happens
bigger surface area=easier for diffusion to happen
the big surface area isn’t associated with one capillary, it is when all of them are combined the overall surface area of capillaries as a whole is huge
78
how big is the surface area of arteries? how about arterioles?
there are few arteries = small surface area
arterioles have intermediate SA
capillaries have the highest surface area which helps us with diffusion
79
what does increased surface area help with? where does this come in handy?
surface area area also helps with hydrostatic pressure by spreading it
the capillaries have the lowest amount of hydrostatic pressure
the capillaries are made of one cell layer and won’t handle hydrostatic pressure very well so they need to have very low hydrostatic pressure so these thin walls protect against HP
capillaries aren’t built for strength, they’re build for diffusion
80
where is the lowest hydrostatic pressure in the body?
capillaries
because of increased surface area which helped spread hydrostatic pressure
81
what is the flow rate in capillaries?
decreased flow rate which makes sense because only one RBC being able to move through at once
82
why is the flow rate in capillaries suitable?
there is low flow rate in capillaries
this is good for diffusion because it gives time for diffusion to happen
the decreased flow rate allows more things added much like a slow conveyor belt rather than a fast conveyor belt – a slow conveyor belt gives you time to pull things off of it
83
what is the pattern of BP in the different vessels of the body?
arteries have the highest BP
arterioles have intermediate BP
capillaries
veins have the lowest BP
84
where is the lowest BP in the entire body?
veins
veins have the lowest blood pressure because it decreases with distance and these veins are furthest from the heart since veins return blood to the heart
85
do veins have valves?
yes
BP going back to the heart is lower and you’re often going against gravity so you want to make sure the blood keeps going in the right direction so you again, need 1-way valves so that as blood moves towards the heart
if anything flows backwards they’ll close and stop it to make sure it continues towards the heart
86
where are many of our veins located?
many of our large veins run within our skeletal muscles
87
how can you help increase the blood pressure in the veins?
the flow through our veins is caused by heart which pushes blood and causes pressure
BP is the lowest in our veins and many of our veins are within our skeletal muscles
we can help this pressure since it’s low by squeezing skeletal muscle to create an additional force to prevent movement in the wrong way and help the heart move the blood back towards it
88
why do people move around when their leg falls asleep?
o When people sit for a while get restless and want to move their legs because they’re starting to have issues with return flow so squeezing leg muscles gets better flow
skeletal muscle is not the reason for the flow, it is only helping the flow (heart is what causes the flow)
89
what is the level of hydrostatic pressure in the veins?
the hydrostatic pressure in the veins is higher than in the capillaries even though HR/BP is decreased because the surface area of veins is smaller
90
what is the level of hydrostatic pressure in the vessels of the body?
arteries (highest)
arterioles
veins
capillaries (lowest)
91
hydrostatic vs. blood pressure
BP: linear movement of the blood to or from the heart = parallel to the walls of vessels
hydrostatic pressure is perpendicular to the walls of the vessels
92
what is arterial blood pressure?
PV=nRT
V = volume/size of vessels
n = volume/amount of blood
93
what is the relationship between volume of blood and pressure?
volume/amount of blood is the “n” in the equation
this is a direct relationship between volume of the blood and the pressure
P = n/V
94
what's the relationship between the volume of the vessel and blood pressure?
inverse
95
how does rigidity of vessel walls effect blood pressure?
changing the size of the vessel deals with how rigid the walls are (arteries should be elastic)
as we make the walls more rigid and less elastic, our ability to change the V decreases, which sets limits to change the blood pressure
96
what pattern does blood pressure have in large vessels?
large vessels = arteries
in large vessels blood pressure mirrors cardiac cycle aka it has 2 phases
97
what are the two phases of blood pressure in large vessels?
systolic and diastolic phase
98
what is the systolic phase of blood pressure in large vessels?
this is the squeeze
it’s the end of the contraction= big blood pressure because we’re decreasing V
max BP
99
what is the diastolic phase of blood pressure in large vessels?
relaxing before contraction
lower BP (not zero)
minimum BP
100
what is the top number of blood pressure?
systolic pressure
101
what is the bottom number of blood pressure?
diastolic pressure
102
what does it mean if the top number in BP is too high?
systolic pressure is too high
aka the heart is working too hard which is a problem
103
what does it mean if the bottom number in BP is too high?
diastolic pressure
how well does your heart relax
it's not a big deal if this number gets too low
104
does arterial pressure differ in parts of the body?
arterial blood pressure in different points of your body shouldn’t really differ
105
what do arterioles do?
they regulate the blood flow to specific tissue/organs
106
does arteriolar pressure differ across the body?
yes
it's regulating flow to specific tissue/organs
this fact is normal and how it should be, some areas need more of this blood flow and glucose and some of these areas need less blood
if you increase arteriolar pressure in one place, a different place will decrease so no one is ever equal - the arteriolar level is where we get tradeoffs happening
blood pressure going to liver is different that blood flow to spleen
107
what are the three methods for accomplishing size change of arterioles? aka how do you change arteriolar BP?
1) local factors
2) extrinsic control
3) endothelial cell secretions
108
how do local factors control arterioles BP?
the local area, that tissue or organ themselves is what’s controlling how much blood comes to it
they do it via paracrine and autocrines = local factors because they travel short distances so not endocrines or NT
109
what are the two ways to control arteriolar BP via local factors?
1) active hyperemia
| 2) flow autoregulation
110
what is active hyperemia?
when there's increased flow to an area due to increased metabolic activity
if we’re metabolically active, that means we’re making CO2 and dropping levels of O2 which is the trigger for the arterioles to bring more blood to this area
there’s a limited overall flow though so if you raise the flow to this organ/tissue it means a decreased flow to a different area
111
what happens if you try to move every single muscle in your body at the same time?
if you try to move your whole body via skeletal muscles, then what loses the flow of blood is your brain, heart, etc. so we have a limitation on active hyperemia because there’s vital organs that need blood flow and they need a particular level of blood flow
112
what is flow auto regulation?
it counteracts active hyperemia
it's set up by the key organs so that active hyperemia doesn't pull too much blood flow from vital organs and that they maintain the proper amount of blood flow that they need
arteriole changes to maintain consisten flow to key organs
113
does the digestive system do flow auto regulation?
no because the sympathetic system can shut down the digestive system
114
how does extrinsic control of arteriolar BP work?
it's done via more distant factors such as endocrines or NTs
115
does the parasympathetic have an impact on extrinsic control of arteriolar BP?
it have a small impact on arteriolar BP b/c arteriolar BP will come down naturally so why use energy to bring it down
116
does the sympathetic have an impact on extrinsic control of arteriolar BP?
it has a lot of control of arteriolar BP because it can bring it up super fast for fight or flight
117
what is flow?
the amount of blood moving
118
what are the two ways to control arteriolar BP via extrinsic control?
1) vasodilation
| 2) vasoconstriction
119
what is vasodilation?
making the vessel wider
which is changing our V= increased flow through that area
speed is slower, low/ decreased blood pressure
120
what causes vasodilation?
1) nitric oxide: it's a free radical so there's tradeoffs
| 2) epinephrine in skeletal muscles
121
what is vasoconstriction?
making the vessel skinnier
which is changing our V= decreased flow through that area
speed is faster, high/ increased blood pressure
like putting your thumb over a host to make water come out faster
122
what causes vasoconstriction?
1) vasopressin and angiotensin II endocrines
| 2) norepinephrine and epinephrine from sympathetic nervous system
123
is epinephrine a vasoconstrictor or dilator?
both!
it's a vasoconstrictor outside the skeletal muscle
within the skeletal muscle it’s a vasodilator
124
what's the goal of the sympathetic nervous system?
fight or flight
to do that, you need to be engaging skeletal muscles which need blood moving nice and slow and you need a lot of it
when you do vasodilation at skeletal muscle you get more blood there and you’re getting it to go slower because that’s where you want the exchange of oxygen to happen – aerobic gets us tons of ATP
125
how do endothelial cell secretions regulate arteriolar BP?
the vessels themselves controlling how much blood is going through them – all vessels are lined with endothelial cells
done via paracrine that impact the surrounding smooth muscles to control blood
126
how is vasodilation done through endothelial cell secretions?
nitric oxide (NO)
sympathetic vasodilation is done via epinephrine which is the only exception
127
how is vasoconstriction done through endothelial cell secretions?
it's caused by endothelia-1 (ET-1)
128
what are baroreceptors?
just a fancy name for mechanoreceptors because they just tell you about pressure
you're measuring something that's going on in your body so they receive afferent signals (going to the brain)
129
where are baroreceptors found?
in large arteries like the carotid in your neck or the aorta
why do you want to know the BP in your neck? It’s the blood feeding your brain and if you don’t have the right blood flow to your brain everything else is useless
130
where do baroreceptors input information?
they input to the brainstem which is the key to life
the brainstem deals with cardiac activity like heart rate and blood pressure
131
how do baroreceptors work?
they register to see what the stretch is then sends that information via AP that then gets turned into NT to the brainstem for it to process
132
what kind of regulation do baroreceptors provide?
short-term regulation
you standing up changes your BP like when you get up too fast and feel light headed because you dropped BP enough that blood flow to brain was decreased
133
what happens if short term you register high blood pressure?
It gets registered with baroreceptors that send higher than normal AP frequency to brain stem
brainstem registers this and realizes it needs to compensate on the efferent side and get BP to go down which is an efferent autonomic process and we specifically want parasympathetic system to kick in to lower BP
the activity of sympathetic is lowered because you’re trying to lower BP
now the BP is lowered and you’ve completed negative feedback to get us back to steady state
134
what if you have a drop in blood pressure?
Baroreceptors send less AP
brainstem registers this and increases sympathetic and decreases parasympathetic so that BP increases
135
is low or high blood pressure worse?
high BP in short term was a short term issure, but eventually it’ll come back down so using the NS to fix this is fine
but for a low BP, if the BP is too low, cells aren’t getting the oxygen that they need so they can’t make ATP that they need and things have more problem
low BP is far worse than high BP so using just the NS isn’t enough
you also need to use the endocrine system to fix low BP such as angiotensin II and vasopressin into the system because they both cause increased BP since they’re both vasoconstrictions
(you wouldn't want to put in nitric oxide)
136
how is blood pressure regulated long term?
primarily based on blood volume...increased n means increased P
this is regulated by the kidneys which create urine to filter our blood
individuals with high BP are put on diuretics because they make them urinate more which drops blood volume by having more fluid leave your body via the urine
137
what can cause increased blood pressure long term?
1) low O2
2) increase CO2
3) skin pain
138
how does low O2 increase BP long term?
low oxygen levels means you need to get blood moving more and raise BP to get more O2 out to the tissues and get more blood flowing through the lungs to pick up oxygen
139
how does increased CO2 increase BP long term?
if it’s the tissues causing this because the tissues are working a lot, this would lead to increased CO2 and you don’t want too much CO2 in the system
140
how does skin increase BP long term?
if you have skin pain you’ll get fight or flight response started which is an easy indication you need to increase BP
like if you're being scratch by a dog
141
what things can caused a decrease in blood pressure long term?
1) visceral pain
| 2) sleep
142
how does visceral pain decrease blood pressure long term?
visceral pain means organs are screaming
it’s not just that your skin is broken, it means your intestines are being ripped apart and you could be having internal bleeding and you don’t want to bleed out so you lower BP so you can get away and recover
143
how does sleep decrease blood pressure long term?
drop in BP when you sleep which is tied to metabolism because when you sleep you don’t need a lot of energy so you can let off on the heart and let it rest
this is why heart attacks usually happen first thing in the morning because your heart is rested and then you wake up and need to start your heart back up and if something isn’t working properly that could be the breaking and it won’t start up right
144
what is hypotension?
low BP
145
what are the two types of hypotension?
1) hemorrhage
| 2) shock
146
what is hemorrhage?
low BP
loss of plasma fluids
if you cut open your closed system and your “n” is leaking out so P also drops (PV = nRT)
if someone goes to ER and has a lot of bleeding, get them on an IV to replace fluids
later if necessary you might need to add blood
147
what is shock?
low BP
you get individuals that are in the ER getting pushed to the side because they weren’t bleeding but they died because they were actually experiencing visceral pain which is associated with drop in BP because of internal bleeding
visceral pain gets lowered BP and then other organs are unhappy so you lower BP more which is positive feedback
if positive feedback doesn’t get stopped and resolved, you’ll keep going in the wrong direction and that’s what happened to those patients
now the first thing paramedics look at are symptoms of shock regardless of anything else going on
