Control of Cardiac Function Flashcards

1
Q

What is the total oxygen consumption of the body?

A

250ml of oxygen a minute

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

What is the total oxygen consumption by the brain?

A

50ml of oxygen a minute

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

How is a constant flow of oxygen to the brain achieved?

A

By a constant blood pressure and a constant partial pressure of oxygen

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

What is the formula for ABP?

A

ABP = TPR x CO

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

What controls total peripheral resistance?

A

Blood vessel diameter

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

What is the formula for CO?

A

CO = HR x SV

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

What is the stroke volume otherwise known as?

A

The force of contractility

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

What is the normal stroke volume

A

70ml of blood per beat

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

How do you work out stroke volume?

A

EDV - ESV

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

What is the normal heart rate?

A

70bpm

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

What is the total cardiac output?

A

70ml x 70bmp = 4900ml = about 5L/min

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

What is the regular blood pressure?

A

120/80mmHg

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

What is intrinsic regulation?

A

How the heart functions without an stimulus from the outside (neural or hormonal)

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

In an isolated heart what is the heart rate and where is it generated?

A

70bpm generated in the sino atrial node

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

If the sino atrial node is removed where is the heart beat generated and what is the rate?

A

In the atrio-ventricular node and is 60bpm

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

If the sino atrial node and the atroventricular node are both removed in the isolated heart where is the heart beat generated and what is the rate?

A

In the ventricular muscle at 30bpm

17
Q

What does starlings law of the heart state about the contractility of the heart?

A

The more you stretch the heart the greater the force of contraction (stroke volume)

18
Q

What is preload?

A

Venous return - the volume of blood coming back to the heart that has to be pumped out again

19
Q

What happens when preload is increased?

A

The amount of blood returning to the heart (venous return) increases so the end diastolic volume increases so the heart is stretched more and the force of contraction is greater

20
Q

What is afterload?

A

the pressure the left ventricle must pump against inorder to get blood into the aorta

21
Q

What happens when afterload is increased?

A

The contractility of the heart increases due to the stretch of the left ventricle being greater by more blood coming in and so produces a greater stroke volume to pump it out again

22
Q

What is more influential in the increase is cardiac contractility prelaod or afterload?

A

Preload