Blood pressure

Question 1

Define blood pressure

Answer 1

• Blood pressure is the force exerted by the blood against the blood vessel wall.
• Blood flow x resistance.

Question 2

What are the 2 types of blood pressure?

Answer 2

1. Systolic blood pressure
2. Diastolic blood pressure

Question 3

Define systolic blood pressure

Answer 3

• The pressure in the arteries when the ventricles contract.
• TOP NUMBER!!

Question 4

Define diastolic blood pressure

Answer 4

• The pressure in the arteries when the ventricles relax.
• BOTTOM NUMBER!!!

Question 5

What is the average blood pressure?

Answer 5

120/80

Question 6

Effects of exercise on blood pressure: aerobic exercise

Answer 6

1) Systolic bp increases.
2) Diastolic bp remains constant.

Question 7

Effects of exercise on blood pressure: anaerobic exercise

Answer 7

1) Systolic bp increases.
2) Diastolic bp increases

Question 8

What is venous return + what happens to it during exercise?

Answer 8

• it is the blood returning to the heart via the vena cava.
• During exercise venous return increases.

Question 9

Recap: what is Starlings law?

Answer 9

1. Increased venous return.
2. Greater diastolic filling.
3. Cardiac muscle stretched.
4. More force of contraction.
5. Increased ejection fraction.

Question 10

What happens to blood when it travels away from the heart?

Answer 10

• After travelling away from the heart, blood pressure drops significantly once it enters the veins.
• Blood cannot rely on just the heart beating to bring it back to the heart, so it uses other mechanisms.

Question 11

What are the 5 venous return mechanisms?

Answer 11

1. Skeletal pump.
2. Respiratory pump.
3. Valves
4. Smooth muscle
5. Suction pump.

Question 12

What is the skeletal pump?

Answer 12

When the muscles contract, and squeezes the veins, pushing blood back towards the heart.

Question 13

What are valves?

Answer 13

• Prevent the backflow of blood and make sure that blood travels in one direction.

Question 14

What is the smooth muscle?

Answer 14

• A thin layer of muscle in the veins that helps squeeze blood back towards the heart.

Question 15

What is the respiratory pump?

Answer 15

Increased breathing rates alter the pressure in the chest cavity, which in turn compresses nearby veins and assists blood flow back to the heart.

Question 16

What is the suction pump?

Answer 16

• When the heart beats forcefully, it sucks blood in when relaxing.

Question 17

Venous return (at rest)

Answer 17

• At rest the valves and the smooth muscle are enough to maintain venous return.

Question 18

Venous return (during exercise)

Answer 18

• Important that venous return increase during exercise in order to supply the muscles with enough O2.
• During exercise the body must rely on the respiratory and skeletal pumps in order to maintain a stable O2 supply.

Question 19

What effects blood pressure?

Answer 19

1. Age’
2. Blood viscosity
3. Health factors (diet, stress etc)
4. Blood vessel diameter + length
5. Stroke volume