Cardiac Output, HR, SV, BP

Question 1

What is cardiac output?

Answer 1

Volume of blood ejected from ventricles in 1 minute (SV x HR)

Question 2

What is stroke volume?

Answer 2

Volume of blood ejected from ventricles per contraction

Question 3

What is heart rate?

Answer 3

Number of beats per minute

Question 4

What is a normal adult heart rate?

Answer 4

50-100 bpm

Question 5

What are (3) hormones released to increase heart rate?

Answer 5

• Catecholamines
• Adrenaline
• Noradrenaline

Question 6

What is a hormone released to decrease heart rate?

Answer 6

Acetylcholine

Question 7

What happens to cardiac output during exercise?

Answer 7

Increases due to higher heart rate

Question 8

What should stroke volume be (approx.)?

Answer 8

Approx. 70mL/beat

Question 9

What is normal adult blood pressure?

Answer 9

Systolic / Diastolic
95-140 / 60-90 mmHg

Question 10

What is blood pressure?

Answer 10

Pressure exerted by blood against the inner wall of an artery

Question 11

How is blood pressure maintained?

Answer 11

• Heart rate
• Stroke volume
• Total peripheral resistance

Question 12

How do we calculate blood pressure?

Answer 12

Blood pressure = Stroke volume X Heart rate X Total peripheral resistance

Question 13

What is total peripheral resistance?

Answer 13

Friction encountered by blood as it passes through a peripheral artery

Question 14

How is blood pressure regulated?

Answer 14

By baroreceptors located in pressure receptor zones:
- High pressure zones (e.g. aortic arch)
- Low pressure zones (e.g. venae cava, atria, pulmonary veins)

Renal system
- long term regulation via altering blood volume

Question 15

How do baroreceptors cause adjustments to blood pressure?

Answer 15

Baroreceptors send signals to the medulla (in brainstem) where autonomic nervous system stimulation leads to adjustments

Question 16

Describe Frank Starling law?

Answer 16

The greater the venous return, the greater the stroke volume