Lecture 7&8 Cardiac Output, resistance and flow blood pressure Part 1

Question 1

What is Heart Rate?

Answer 1

(HR) The number of contractions per minute

Question 2

What is Stroke volume?

Answer 2

Stroke volume or SV is the volume of blood ejected per contraction

Question 3

What is Cardiac output

Answer 3

Cardiac Output (CO) is the volume of blood pumped out of the left ventricle (right ventricle) per minute

Question 4

What is Venous Return?

Answer 4

The volume of blood returning to the heart right or left ventricle per minute

Question 5

What does this equation mean? CO = HR x SV

Answer 5

Cardiac output(l/min) = Heart Rate(Beats/min) times Stroke Volume (ml/beat). The answer will be in ml (1000ml) and will need to be converted to Litres (1L)

Question 6

True or false? Sympathetic activation increases HR

Answer 6

True

Question 7

True or false? Sympathetic activation decreases HR

Answer 7

False

Question 8

True or false? parasympathetic activation increases HR

Answer 8

False

Question 9

True or false? parasympathetic activation decreases HR

Answer 9

True

Question 10

Hormones such as adrenaline or noradrenaline act on adrenergic receptors (Beta receptors) from the parasympathetic or sympathetic?

Answer 10

sympathetic

Question 11

What is the difference between alpha and beta receptors?

Answer 11

Beta receptors are on the heart, alpha receptors are in the arteries or veins

Question 12

What are the three ways we can increase stroke volume?

Answer 12

Increase pre-load (end diastolic volume) decrease after-load (aortic blood pressure) Increasing contractility

Question 13

Pre-load is defined as what?

Answer 13

The degree of stretch of the ventricular wall prior to contraction.

Question 14

For practical purposes, what is measured as a ventricular end-diastolic volume?

Answer 14

Pre-load

Question 15

After-load is defined as what?

Answer 15

the pressure that the ventricles must overcome to eject blood.

Question 16

The aortic pressure (diastolic) at the time the aortic valve opens is defined as Pre-load or After-load?

Answer 16

After-load

Question 17

Is this pre-load or After-load?

Answer 17

After-Load

Question 18

Is this Pre-load or After-load?

Answer 18

Preload

Question 19

An increase in venous return will result in what?

Answer 19

An increase in end-diastolic ventricular volume

Question 20

An increase in end-diastolic ventricular volume results in what?

Answer 20

An increasd force of ventricular contraction

Question 21

An increasd force of ventricular contraction results in what?

Answer 21

An increase stroke volume

Question 22

An increase stroke volume results in what?

Answer 22

an increase cardiac output

Question 23

An increase in after-load results in what?

Answer 23

Reduced stroke volume

Question 24

Reduced stroke volume results in what?

Answer 24

increase end-systolic ventricular volume

Question 25

increase end-systolic ventricular volume results in what?

Answer 25

increased end-diastolic ventricular volume

Question 26

increased end-diastolic ventricular volume results in what?

Answer 26

increased force of contraction

Question 27

increased force of contraction results in what?

Answer 27

stroke volume incrases, back towards original value.

Question 28

Cardiac contractility is defined as what?

Answer 28

the ability of the heart to contract, at any given end-diastolic ventricular volume.

Question 29

Increases in cardiac contractility are caused by what?

Answer 29

activation of cardiac sympathetic nerves or an increase in circulating adrenaline

Question 30

Decreases in cardiac contractility are caused by what?

Answer 30

activation of cardiac parasympathetic nerves that produces a decrease in myocardial intracellular

Question 31

What are the three factors that control the venous return?

Answer 31

Skeletal muscle pump (increases VP Peripheral) Respiratory pump (decreases VP Central) Sympathetic venoconstriction (increases VP Peripheral)

Question 32

What is Venoconstriction?

Answer 32

Venoconstriction is the contraction of skeletal muscle to push blood back up to the heart

Question 33

How do you find out the mean arterial pressure

Answer 33

Find out the diastolic pressure, add a third of the Pulse pressure. Pulse pressure is systolic pressure minus diastolic pressure, Divide the PP by 3 to get a third. DBP + 1/3PP MAP = 80 (120-80)/3=93.33