Lecture 8: THE HEART AS A PUMP Flashcards

1
Q

How is the heart in the mammalian cardiovascular system?

A

Four chambered (atria and ventricle on each side)

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

How does the blood flow in the mammalian cardiovascular system?

A

In one direction

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

Where does arterial blood flow?

A

Away from the heart (not always oxygenated)

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

Where does venous blood flow?

A

Towards the heart (not always deoxygenated)

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

The heart is …

A

Two pumps that lie in series

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

What is the first part of the heart series?

A

Right atrium

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

What comes after the right atrium?

A

Right ventricle

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

What comes after the right ventricle?

A

Lungs

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

What comes after the lungs?

A

Left atrium

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

What comes after the left atrium?

A

Left ventricle

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

What comes after the left ventricle?

A

All organs

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

What goes through the two circuits?

A

Equal flow

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

What happens when the atria contract?

A

AV valves are open to allow the ventricle to fill while the semilunar valves are closed so that pressure builds up in the ventricles

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

What happens when the ventricles contract?

A

AV valves close so as the ventricles contract it puts force on the blood and makes sure the blood doesn’t flow backwards.

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

What happens when pressure gets great enough?

A

The semilunar valves open and ejection of the blood occurs

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

What contracts simultaneously?

A

Right and left pumps

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

What contracts first?

A

Atria

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

What contracts second?

A

Ventricles

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

What do valves do?

A

Open and close to direct blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the thin filament?

A

Actin (light coloured)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the thick filament?

A

Myosin (blue coloured)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How are calcium levels during relaxation?

A

Low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What happens after relaxation (calcium levels)?

A

Ca2+ levels go up and more ca2+ is released form the sarcoplasmic reticulum (SR)

24
Q

What happens when calcium levels rise?

A

Myosin binds to actin to form cross bridges

25
Q

What happens after myosin binds to actin to form cross bridges?

A

Myosin pulls on actin to shorten the sarcomere and generate force (head changes position)

26
Q

What is activated during every beat?

A

Every cardiomyocyte

27
Q

How can the force of contraction be increased?

A

Increasing cytosolic calcium levels, increasing number of cross bridges formed

28
Q

What happens during relaxation (calcium levels)?

A

Decrease in cytosolic calcium levels as calcium is pumped back into the SR

29
Q

When do cross bridges release?

A

When ATP binds to myosin

30
Q

What does a reduction in force mean?

A

The heart can relax

31
Q

What do all cardiomyocytes do each beat?

A

Relax

32
Q

What is diastole?

A

Relaxing and falling pressure

33
Q

What is systole?

A

Contracting and rising pressure

34
Q

When does the cardiac cycle begin?

A

All four chambers are relaxed and partly filled with blood ready to contract

35
Q

What is the first phase of the cardiac cycle?

A

Atrial systole

36
Q

What happens in atrial systole?

A

Atria contract and fill the ventricles with blood. AV valves open and semilunar valves closed

37
Q

What is the phase after atrial systole?

A

Ventricular systole (isovolumetric contraction)

38
Q

What happens in ventricular systole (isovolumetric contraction)?

A

The volume of the bold in the ventricles remains the same as the atria relax and ventricles begin to contract. Both valves are closed

39
Q

What is the phase after ventricular systole (isovolumetric contraction)?

A

Ventricular systole (ventricular ejection)

40
Q

What happens in ventricular systole (ventricular ejection)?

A

Semilunar valves open when the pressure build up so that blood can be released into the arteries

41
Q

What phase is after ventricular systole (ventricular ejection)?

A

Isovolumetric ventricular relaxation

42
Q

What happens in isovolumetric ventricular relaxation?

A

Blood has been pushes out and semilunar valves snap shut. AV valves open, heart relaxes and falling pressure of the blood

43
Q

What phase is after isometric ventricular relaxation?

A

Ventricular diastole

44
Q

What happens in ventricular diastole?

A

All chambers relax and the atria begin to fill passively

45
Q

Which circuit has higher pressure?

A

Systemic

46
Q

What is the highest blood pressure?

A

Systolic blood pressure

47
Q

What is the lowest blood pressure?

A

Diastolic blood pressure

48
Q

What is the mean pressure?

A

The average pressure across the whole pulse and almost always closer to diastole because the heart spend more time in this phase

49
Q

What is pulse pressure?

A

The difference between the highest and lowest points

50
Q

What is hypertension?

A

High blood pressure

51
Q

What is hypotension?

A

Low blood pressure

52
Q

What is the pressure in the systemic circulation?

A

High (110mmHg)

53
Q

What is the pressure in the pulmonary circulation?

A

Low (25mmHg)

54
Q

How is the flow equal in both circuits?

A

Resistance - the pulmonary circuit has less resistance than the systemic circuit

55
Q

What is flow equal to?

A

Pressure difference/resistance