Lecture 9 Cardiovascular Flashcards

(60 cards)

1
Q

what causes blood to move throughout the circulatory system

A
  • pressure differences throughout the circulatory system

- pressure higher in aorta and decreases to almost 0 in vena cava

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2
Q

2 parts of the heart

A
  • right = pulmonary, left = systemic
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3
Q

4 chambers of the heat and general role

A

2 atria that receive blood
2 ventricle that pump blood out of heart
- left atria receives unoxygenated blood
- left ventricle pumps blood to lungs / pulmonary circulation
- right atria receives oxygenated blood from lungs
- right ventricle pumps oxygenated blood to the body

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4
Q

2 types of valves, total of 4 valves

A
  • AV = atrioventricular - connects atria and ventricles
  • semilunar = goes from ventricles to arteries
  • AV = tricuspid in right heart and bicuspid aka mitral in left heart
  • semilunar = pulmonary valve in right heart and aortic valve in left heart
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5
Q

part of heart that separates chambers

A

fibrous skeleton

- atria attached on top and ventricles attached to the bottom

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6
Q

venous return meaning

A

unoxygenated blood that is returning to the heart through the superior and inferior vena cava

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7
Q

describe flow of blood through the circulatory system (entire flow)

A

vena cava –> right atria –> tricuspid valve –> right ventricle –> pulmonary valve –> pulmonary arteries –> lungs and pulmonary capillaries and alveoli –> gas exchange and oxygenation –> pulmonary veins –> left atria –> mitral valve –> left ventricle –> aortic valve

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8
Q

describe the relationship between resistance, pressure, and radius of the lumen

A
  • smaller radius –> increased resistance and pressure

- blood has to work harder if pressure and resistance are high

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9
Q

which ventricle does more work and why

A
  • left ventricle works harder because blood pressure in systemic circulation is higher than that of pulmonary circulation
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10
Q

describe how hypertension can lead to congestive heart failure

A

hypertension –> increased system blood pressure –> left ventricle has to work harder –> thickening of left ventricle heart muscle –> cavity of left ventricle becomes smaller –> not enough blood being pumped

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11
Q

effect of exercise on cardiovascular system (blood pressure)

A
  • decreased systemic bp so heart doesnt have to work as hard
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12
Q

eversion aka prolapsing of valves

A
  • valves flip out the opposite way
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13
Q

what causes valves to open

A

changes in blood pressure

- when bp is higher downstream then upstream valves open

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14
Q

papillary muscle

A

prevent valves from prolapsing

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15
Q

chorda tendinea

A

tendons that connect valves and papillary muscle

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16
Q

3 names for valves that can become prolapsed

A

regurgitative, incompetent, insufficient

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17
Q

systole vs diastole

A
systole = contraction of ventricles 
diastole = relaxation of ventricles
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18
Q

end diastolic volume

A

volume in ventricles after relaxation when it fills with blood

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19
Q

end systolic volume

A

volume in ventricle after contraction when blood gets pushed out

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20
Q

stroke volume and 2 representations

A

end diastolic volume - end systolic volume

  • how much blood as ejected
  • percent = amount ejected / end diastolic volume
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21
Q

isovolumteric contraction

A
  • ventricles are contraction and AV valve is closed but semilunar valves have not yet opened
  • no change in volume
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22
Q

isovolumetric relaxation

A
  • semilunar valves have closed and AV valves are still closed but are about to open
  • ventricles are relaxing
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23
Q

describe flow / 5 parts of the heart beat

A
1 = isovolumetric contraction - ventricles being to contract and pressure rises but semilunar valves not yet open 
2 = ventricle contraction and semilunar valves open = blood is ejected 
3 = isovolumetric relaxation - AV and semilunar valves are closed, ventricles are relaxed 
4 = passive filling of ventricles due to pressure differences 
5 = atria contract to fill ventricles
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24
Q

what causes sounds of the heart

A
lub = closing of AV valves 
dub = closing of semilunar valves
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25
heart murmur definition
- abnormal heart sounds caused by abnormal flow of blood in heart
26
2 causes of heart murmurs (just list them)
- congenital = born with | - rheumatic fever
27
rheumatic fever
- antibodies made in response to strep end up binding to valves and causing autoimmune response
28
systolic vs diastolic murmur and sound order
``` systolic = lub shhh dub diastolic = lub dub shhh ```
29
mitral valve prolapse - what type of murmur
- mitral valves evert/prolapse when closed | - systolic because mitral/AV valves are closed during ventricle contraction
30
mitral stenosis - meaning and what type of murmur
- calcification of valves preventing them from opening fully - diastolic because AV / mitral valve open during ventricle relaxation when it is filling with blood
31
septum description
separates right and left heart, thicker between ventricles
32
congenital septal defect
hole in the septum, may close after birth but if not causes shunting of blood from one side of heart to the other
33
gap junctions of myocardial cells
allow electricity to pass from one cell to another
34
can electrical activity pass from chamber to chamber directly? why?
no! due to fibrous skeleton and septum
35
pacemaker cells
cells that can generate their own AP
36
HCN channels - what type, where found, when open, and meaning of HCN
Na+ VGIC channels - found in pacemaker cells only - H = hyperpolarization, CN = cAMP increases their frequency of AP - open during hyperpolarization causing pacemaker potential and pacemaker cell to reach threshold
37
affect of sympathetic system on pacemaker cells (entire flow)
sympathetic --> epi/norepi from adrenal medulla --> bind to excitatory beta 1 adrenergic receptor -->
38
describe all stages of AP for pacemaker cells
Na+ entering HCN causes pacemaker potential a spontaneous graded depoalrization --> Ca2+ enters VGIC channels causing steep depolarization --> K+ exits cause steep repolarization and hyperpolarization --> HCN channels open
39
SA node - regular rate, location, and affect of parasympathetic
- 100 bpm - right atria - parasympathetic Ach onto M2 muscarinic receptors, K+ exit causes hyperpolarization and decrease in heart rate
40
atropine mechanism and effect on SA node
- M2 antagonist, decreases affect of parasympathetic on heart - increases heart rate
41
AV node - normal rate, location
- 40-60 bpm - right atria - slower then SA node so never generates its own AP, always depolarized by the SA node
42
AV bundle - alternate name, function
- bundle of His - brings AP from SA node and right atria down septum and to bottom of the heart - splits off into left and right bundle branch and Purkinje fibers on the right
43
Purkinje fibers
- branch off from right bundle branch of AV bundle | - also has pacemaker cells 15-40 bpm
44
sinus rhythm
- heart rate is determined by SA node
45
ectopic pacemaker
heart rate is determined by some node other than SA - AV node or Purkinje fibers, abnormal
46
flow of electricity through heart
right atria --> left atria (both atria contract) --> travels down bundle of His to bottom of heart --> travels up heart and both ventricle contract while both atria relax (and repolarize)
47
EKG function
measure electrical activity fo the heart
48
P wave
atria depolarize
49
QRS complex
ventricle depolarize
50
T wave
ventricle repolarize
51
myocardial cell RMP
-90 (instead of -70)
52
plateau phase - what is it and what is the cause
Ca2+ entering cell makes absolute refractory period longer by keep cell depolarized for a longer period of time
53
importance of plateau phase / long refractory period
- gives heart contraction a chance to finish before next AP is generated - if plateau phase was not present back to back AP could be generated and heart would not relax and refill with blood = tetany
54
excitation-contraction coupling meaning and flow
- excitation of heart muscles causes their contraction - excitation / stimulus --> Ca2+ enters cells --> Ca2+ released from SR (storage inside cell) --> Ca2+ wave occurs --> Ca2+ binds to troponin and causes muscle contraction
55
caffeine effect on heart and mechanism
- inhibits the enzyme that breaks down cAMP | - mimics epi/norepi which increases cAMP and speed of HCN opening = increase in heart rate
56
sympathetic/sympathoadrenal and parasympathetic effect on pacemaker cells (2 flows)
- sympathoadrenal: epi/norepi from adrenal medulla --> beta 1 adrenergic receptors --> increase in cAMP --> HCN channels open faster --> increased heart rate - parasympathetic: Ach onto M2 muscarinic --> K+ channels open and K+ exits causing hyperpolarization --> heart rate decreased
57
blood pressure in pulmonary circulation, aorta, and venous return
``` arterial = 100-120mmHg pulmonar = 15 mmHg venous = 0-10 mmHg ```
58
problem if pressure in pulmonary system was too high
if pressure too high blood would be squeezed out of capillaries and fill alveoli
59
passive vs active filling and percentages
- passive = AV valves open, pressure difference moves blood, 90% of filling - active = atria contract, 10% of ventricle filling
60
pacemaker potential
spontaneous graded potential caused by HCN channels opening and Na+ entering