the heart - mech events of the cardiac cycle Flashcards

1
Q

how is cardiac muscle connected

A

through intercalated disks with Gap junctions

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

how is the AP of skeletal muscle different from cardiac

A

skeletal have a shorter AP

Skeletal can do tetanus

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

what happens during the plateau phase of cardiac muscle AP

A

trigger Ca enters the cells

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

what is the roll of the HEart

A

The pump that moves the blood

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

how is cardiac activity expressed

A

Cardiac output (amount of blood moved per unit time)

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

what is the average cardiac output

A

5 liters a minute

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

what caues the first heart sound

A

Closure of the AV valves

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

what causes the second heart sound

A

closure of the Aortic and pulmonary valves

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

what is stenosis

A

Narrowing

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

what is regurgitation

A

insufficiency (leaky)

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

what causes murmurs

A

stenosis
regurgitation
septal defects

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

when do you hear stensosi

A

When valves are open

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

when do you hear regurgitation

A

When valves are closed

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

how are the system and pulmonary circulations plumbed

A

in series

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

how are organs in systemic circulation plumbed

A

Parallel

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

what is systole

A

Ventricle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is diastole

A

Ventricles relaxed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what causes the valves of the heart to open

A

Pressure differences on both sides of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how much filling is passive is ventricle

A

80%

20
Q

what does the final portion of filling of the ventricles

A

Artrial kick

21
Q

what happens in isovolumetric contraction

A

both valves closed (aortic pressure is higher than the ventricle)
raising of ventricular contraction

22
Q

how do you know something is isovolumic contraction

A

both valves closed

volume is non-changing

23
Q

when does QRS happen relative to ventricular contraction

A

QRS preceeds ventricular contraction

24
Q

what is the eq for cardiac output

A

Heart ratexStroke volume

25
Q

what pumps more blood, the Right or Left heart

A

pump both the same amount

26
Q

what pumps higher pressure, Right or left heart

A

Left heart is higher pressure

27
Q

what does parasympa and sympa affect in the heart

A

Parasympa closes funny channels

Sympa opens funny channels

28
Q

how can hormones affect the heart

A

release of Epinephrine leads to an increase in HR

29
Q

how can one speed up heart rate

A

deliver more sympa hormone (epinephrine) more sympa neurotransmitter (norepinephrine)
decrease release of parasympa neuro (acetylcholine)

30
Q

can parasympa change stroke volume

A

No

31
Q

what are the three factors influencing stroke volume

A

Preload
Sympa input to the ventricles
Afterload

32
Q

what is preload

A

The volume of blood in the ventricles just before contraction
- end diastolic volume

33
Q

what is afterload

A

the pressure against which the ventricle epumps

34
Q

why does preload increase stroke volume

A

increased stretch of ventricle aligns actin and myosin to a more optimal pattern of overlap

35
Q

how to further increase stroke volume beyond preload

A

preload+ sympa signals

36
Q

how does sympa signals lead to higher stroke volume

A

causes ventricles to relax more rapidly
- more time to refill
causes ventricles to contract more rapidly

37
Q

what does sympa do inside the mycardial cell to increase stroke volume

A

Regulates/increases Ca

38
Q

what is the frank-starling mechanism

A

increased preload leads to increased stroke volume

39
Q

does preload change the amount of inracellular ca

A

no`

40
Q

can you increase stroke volume and increase heart rate separately

A

No, not under normal circumstances

41
Q

how can one measure cardiac function

A
Thermodilution cardiac output
Angiography
Echocardiogram
MRI
ejection fraction
42
Q

what is ejection fraction

A

Measure of contractility

43
Q

what is the formula for ejection fraction

A

(End diastolic volume-end systolic volume)/ End diastolic volume

44
Q

what is hypertrophic cardiomyopathy

A

increased heart wall thickness
myocardial disarray
- specifically interfer with blood ejection

45
Q

what are the symptoms of hypertrophic cardiomyopathy

A

Angina
Arrhythmias
Sudden cardiac death