The Cardiovascular system

Question 1

Describe what cardiovascular drift is

Answer 1

• DECREASE in SV, venous return and arterial blood pressure, INCREASE in heart rate.
• Occurs during prolonged exercise in hot weather despite the intensity of exercise being the same.

Question 2

What happens to blood pressure during exercise?

Answer 2

• blood leaves the heart under high pressure to provide the muscles with O2 quickly.

Question 3

What is systolic pressure?

Answer 3

• pressure of blood against the arterial walls when the left ventricle contracts to allow blood into the heart.

Question 4

What is diastolic pressure

Answer 4

• It is the pressure against the arterial walls as the ventricles relax

Question 5

How is blood redistributed to the heart and then the muscles during exercise?

Answer 5

• more blood goes to the heart as it needs more O2 to beat faster and increase force of contraction
• blood is distributed to the muscles as they need O2 to for energy and to remove CO2 as well as lactic acid

Question 6

What are the venous return mechanisms in the body?

Answer 6

• skeletal muscle pump
• respiratory pump
• pocket valves
• smooth muscle
• gravity
• suction pump

Question 7

How does the skeletal muscle pump function?

Answer 7

• when muscles contract and relax they change shape
• when they change shape they press on nearby veins
• helps pump and squeeze blood to heart

Question 8

How does the respiratory pump work?

Answer 8

• when muscles contract and relax during breathing pressure changes occur in the chest and stomach/abdominal cavities.
• pressure changes compress nearby veins and help blood RETURN to the heart.

Question 9

How do pocket valves work to help blood flow?

Answer 9

• makes sure that when blood only flows one way, no backflow

- once blood has passed through the valves they close to stop the backflow of blood.

Question 10

How do the smooth muscles work as a venous return mechanism?

Answer 10

• This is a thin layer of muscle in the vein walls

- Helps to squeeze blood to heart

Question 11

How does the suction pump work as a venous return mechanism?

Answer 11

• when blood starts to fill the heart, the pressure in the heart is lower as there is more space
• blood is then pulled in by the vena cava.

Question 12

How does gravity act as a venous return mechanism?

Answer 12

• helps blood return to the heart from the upper body

Question 13

How is the skeletal muscle pump affected by exercise?

Answer 13

• significant
• causes increase in muscular contraction and venous return
• very effective as it can happen all over the body but working muscles impact effectiveness

Question 14

How is the respiratory pump affected by exercise and how is it effective?

Answer 14

• significant
• increases respiratory rate and depth
• increased pressure in chest cavity makes sure blood returns to the heart
• it is effective because it is close to the heart.

Question 15

How are pocket valves affected by exercise and how effective is it?

Answer 15

• medium (Only sig when used with skeletal pump)
• increase in the force of contraction increases blood flow
• V effective as it is found in all veins

Question 16

How is the suction pump affected by exercise?

Answer 16

• medium
• the increase in force and rate of contraction allows for more blood to be pulled into the heart.
• Limited effectiveness because as it only acts on veins close to the heart

Question 17

How is the smooth muscle affected by exercise?

Answer 17

• very limited
• involuntary muscles are not impacted by exercise.
• Effective as it is found in every vein / Not effective as it doesn’t increase with exercise

Question 18

How is gravity affected by exercise?

Answer 18

• Limited if person is standing up
• consider the sport in question
• not very effective because it is only useful if the position of the working muscles are above the heart.