Pe As Questions

Front 1

Identify 3 changes in the vascular system when it undergoes exercise

Back 1

Increased blood flow/cardiac output/stroke volume/oxygen delivery to working muscles/delays OBLAPre capillary sphincters/capillaries constrict at organs

Front 2

Explain how gas exchange is increased at the lungs to ensure that a greater amount of oxygen is diffused into the blood during exercise.

Back 2

There is high partial pressure/concentration of oxygen (PO2) in the lungs/alveoli.
There is a low partial pressure/concentration of oxygen (PO2) in the blood.
During exercise there is an increased pressure/concentration
/diffusion gradient.
Faster diffusion will occur.
Increased blood supply/temperature.
Increased surface area of lungs/respiration rate.
Reduced resistance to diffusion.

Front 3

How is oxygen transported in the blood to the working muscles?

Back 3

Dissolved in plasma.
Attaches to haemoglobin.
Forms oxyhaemoglobinb/Hb + O2 ►HbO2.

Front 4

During exercise more oxygen must be supplied to the working muscles.
Describe the passage of oxygenated blood through the pulmonary and systemic networks from the lungs to the working muscles.

Back 4

Blood travels through pulmonary vein.
Enters the left atrium.
Passes through bicuspid valves/AV valves.
Into left ventricle.
Through semi-lunar/aortic valve.
Pumped into aorta.
Travels via arteries/arterioles/capillaries.

Front 5

is recommended that a performer completes a warm up prior to exercise.
Give two effects of a warm up on the vascular system.

Back 5

Increased blood flow/cardiac output/Q/stroke volume.
Which leads to increased oxygen delivery to muscle.
Blood vessels/arteries/arterioles in muscle dilate/vasodilate/opening of pre-capillary sphincters.
Blood vessels/arteries/arterioles to non-essential organs. constrict/vasoconstriction/
closing of pre-capillary sphincters.
Redistribution of blood flow from organs to muscles/vascular shunt.

Front 6

During aerobic performance a large amount of carbon dioxide is produced at the muscles.
How is carbon dioxide diffused from the muscle tissue into the blood during exercise?

Back 6

1. CO2 flows from an area of high pressure to low pressure.
Partial pressure of carbon dioxide (PCO2) is lower in the blood/lower
in the blood.
During exercise there is a greater concentration gradient/diffusion
gradient.
So faster diffusion will occur.
Haemoglobin is able to pick up carbon dioxide more easily when O2 is released.
Greater diffusion capacity for CO2/vasodilation within muscle.

Front 7

Describe the passage of deoxygenated blood through the systemic and pulmonary networks which allows carbon dioxide to be removed during aerobic performance.

Back 7

Transported through capillaries/venules/veins/vena cava
Into right atrium.
Through tricuspid/AV. valve/tricuspid/AV valve closes to
prevent backflow.
Into right ventricle.
Pumped via pulmonary artery to lungs.
Through semilunar/semilunar valves shut to prevent backflow.

Front 8

Identify two ways in which carbon dioxide is carried in the blood during aerobic performance.

Back 8

1. Dissolves in the plasma
2. Combines with haemoglobin
3. Forms carbaminohaemoglobin
4. Dissolves in water/forms carbonic acid/forms H2CO3
5. In plasma dissociates to hydrogen ions/bicarbonate ions

Front 9

Why does an increase in carbon dioxide during exercise increase heart rate? How does this happen?

Back 9

1. Increase in carbon dioxide changes ph/acidity
How (sub max 2 marks)
2. This is detected by chemoreceptors
3. Information sent to Cardiac control centre/CCC
4. Under autonomic control/autonomic nervous system (ANS)
5. Impulses sent via cardiac accelerator nerve
6. SA node is stimulated
7. Known as sympathetic control

Front 10

Describe how the mechanics of breathing alter during exercise to expire greater volumes of carbon dioxide.

Back 10

1. This process becomes active
2. Due to internal intercostals contracting
3. Abdominal muscles contracting
4. Diaphram pushed up harder/rib cage pulled in and down
5. Decrease in volume of thoracic cavity
6. Causing an increased pressure within thoracic cavity

Front 11

Following a training session a coach will require the performer to complete a cool down. How would a cool down aid the vascular system?

Back 11

1. Flushes out lactic acid/waste products/repays oxygen debt
2. Keeps capillaries dilated/maintains blood flow/oxygen to muscles
3. Maintains skeletal muscle pump/respiratory pump
4. Prevents blood pooling
5. Maintains venous return
6. Maintains stroke volume/cardiac output
7. Maintains blood pressure
8. Keeps metabolic activity elevated/gradually decreases heart rate

Front 12

Following the release of oxygen at the tissues the blood is returned to the heart (venous return).
Identify two mechanisms that aid venous return during exercise.

Back 12

1. Valves
2. Respiratory pump
3. (Skeletal) muscle pump
4. Venoconstriction of veins/venomotor tone
5. Gravity forces blood from above heart

Front 13

Give one reason why a good venous return helps an endurance performer.

Back 13

1. Increase stroke volume
2. Increase cardiac output
3. Therefore more blood/oxygen supplied to working muscles
4. Greater amounts of carbon dioxide removed via lungs

Front 14

Describe how hormonal control is used to alter heart rate during the training run.

Back 14

1. Adrenaline/Epinephrine/Noradrenaline is released
2. Stimulates the SA node
3. Increases the heart rate
4. Also increases strength of contraction/stroke volume/cardiac output/Q

Front 15

Describe the mechanisms of venous return that ensure enough blood is returned to the heart during the training run.

Back 15

1. (Skeletal) muscle pump/muscles contract to squeeze blood back
to the heart
2. Valves/direct blood flow back to the heart/prevent backflow
3. Respiratory pump/changes in pressure around abdominal cavity
squeezes/ pulls blood back to the heart
4. Blood above the heart will return due to the effect of gravity
5. Venoconstriction of veins returning blood to the heart

Front 16

Why should the performer warm up before the training run?

Back 16

1. An increase in muscle temperature
2. This allows greater stretch in the muscles/oxygen dissociates from haemoglobin quicker
3. Decreases risk of injury/prevents injury
4. Nerve impulse conduction is quicker
5. Improves muscle contraction speed/faster reaction time/improved
co-ordination of antagonistic pairs
6. Increase in heart rate/respiratory rate/stroke volume/cardiac output
7. This increases blood flow/increased oxygen delivery
8. Increased enzyme activity/hormonal activity
9. More energy available in muscles
10. Blood vessels within the muscle dilate/pre capillary sphincters/
capillaries dilate at muscle
11. Pre capillary sphincters/capillaries constrict at organs/
Redistribution of blood flow from organs to muscles/vascular shunt

Front 17

During aerobic exercise the performer requires the heart to pump more blood to the working muscles.
Define stroke volume and give a value for maximal stroke volume during exercise.

Back 17

The amount of blood ejected by the left ventricle/each ventricle in one beat.
1. mark for value:
2. 100-220 ml/100-220cm3

Front 18

Explain how a performer is able to increase stroke volume during exercise.

Back 18

1. Increase in venous return
2. Due to skeletal muscle pump/respiratory pump/valves
3. Stretches cardiac muscle/heart wall/increases end diastolic volume
4. Leads to an increased force of contraction/increased myocardial
contractility
5. Starling’s Law/Stroke volume is dependent upon venous return
6. Chemoreceptors detect change in pH
7. Increased sympathetic control
8. Impulse travels down cardiac accelerator nerve
9. The release of adrenaline

Front 19

The cardiac cycle explains how the heart pumps blood to the working muscles.
Describe how the conduction system of the heart controls the cardiac cycle in the diastole and systole stages.

Back 19

Diastole phase
1. Heart is in relaxation phase
2. This allows the atria to fill with blood
Systole phase
3. Impulse initiates from sino atrial node (SA node)
4. Impulse (travels across atria) causing atria to contract
5. Impulse received by atrioventricular node (AV node)
6. Impulse conducted down Bundle of His/purkinje fibres
7. Impulse (travels through ventricles) causing the ventricles to contract

Front 20

Describe the changes that occur in the distribution of cardiac output as a performer moves from rest to exercise. Explain how the vasomotor centre controls this distribution.

Back 20

(Describe)
1. More blood is distributed to the working muscles.
2. Less blood is distributed to non-essential organs
(Explanation)
3. Vasodilation of arteries/arterioles supplying working muscles/Vascular shunt
4. Opening/vasoldilation of precapillary sphincters supplying working muscles
5. Vasoconstriction of arteries/arterioles supplying non-essential organs
6. Closing/vasoconstriction of precapillary sphincters supplying non essential organs