Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ExPhys > Textbook Ch2 > Flashcards

Textbook Ch2 Flashcards

1
Q

signaling sequence of the cardiac cycle

A

AP to the SA node
signal spreads through both atria
AV node - slight pause
His-Purkinje complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what happens/what is allowed to occur when the signal hits the AV node

A

slight pause that allows for atrial kick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when in atrial fibrillation, what is lost and what is the significance?

A

atrial kick is lost
15-20% of cardiac output is lost due to stroke volume decreasing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when speaking of systole and diastole, which chambers are referenced

A

ventricles contracting or ventricles relaxing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what causes S1

A

tricuspid and mitral valve closure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does S1 signal?

A

onset of ventricular systole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

on the ECG, what portion is ventricular contraction

A

top of R in QRS complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

explain isovolumetric contraction

A

ventricular muscles contract with all valves closed
- pressure increases and volume remains the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

importance of isovolumetric contraction

A

increase the pressure in the left ventricle to overcome the pressure in the aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

atrial pressure increasing during isovolumetric contraction of the ventricle is due to

A

retrograde bulging of the mitral valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what event(s) cause(s) S2

A

aortic and pulmonary valves closing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what terminates systole

A

aortic valve closing
- end of ventricular ejection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what does S2 signal

A

isovolumetric relaxation in the atria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is diastasis

A

slow-filling phase of the ventricle that occurs after the rapid-filling phase

– lasts until atrial systole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

mechanical events related to the P Wave

A

start of P wave
– ventricles fill passively

end of P wave ends
– atria contract and contribute 15-20% of EDV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

importance of QRS complex

A

isovolumetric ventricular contraction

17
Q

when does ventricular ejection occur on an ECG

A

early portion of ST segment

18
Q

what is the significance of the T wave in QRS complex

A

repolarization of the ventricular fibers

19
Q

where is atrial repolarization found in the ECG

A

cannot be seen, but it occurs during the QRS complex

20
Q
A
21
Q

what is the average pressure needed to open the aortic valve

A

120 mmHG

22
Q

what is CO? how to calculate

A

cardiac output

heart rate x stroke volume

23
Q

what is the average cardiac output at rest

A

4-6 L/min

24
Q

how long does it take for blood to complete systemic/pulmonary circuits

A

approx 1 min

25
Q

explain HR rising in a biochemical sense

A

epinephrine - adrenal gland
norepinephrine - SNS axons
– open channels of the pacemaker cells of the SA Node and increase the rate of depolarizations and thus HR

26
Q

explain HR lowering in a biochemical sense

A

ACh released by vagus nerve endings
decrease the rate of AP production at the SA node

27
Q

what sets the tone of the SA node

A

net effect of SNS and PSNS

28
Q

chronotropic effect

A

mechanisms that alter the cardiac rate
increase HR = positive chronotropic
decrease HR = negative chronotropic

29
Q

ionotropic effect

A

factors that affect the contractility of the myocardium

30
Q

positive ionotropic medications increase

A

contractility of the heart

leading to increased cardiac output

31
Q

how do Beta Blockers effect HR of patients when exercising

A

diminished HR response

myocardial receptors are unable to respond to sympathetic stimulation

32
Q

variables that regulate stroke volume

A

preload
contractility
afterload

33
Q

what is preload often associated with

A

end diastolic volume

34
Q

what is end diastolic volume

A

maximum amount of blood that can be in the ventricles prior to contraction

35
Q

relationship between preload and stroke volume

A

directly correlated
more EDV more SV

36
Q

what is the Frank-Starling mechanism

A

explains how greater volume of the blood is ejected when more blood is returned

37
Q

preload

A

stretch/load on the myocardial wall prior to contraction

– directly influenced by end diastolic volume

38
Q

what intrinsic factors affect contractility

A

degree of myocardial stretch

ExPhys (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions