cardiovascular system during exercise of differing intensities and during recovery.

Question 1

what is the effect of sub-maximal intensity exercise on heart rate?

Answer 1

1. anticipatory rise - rise in HR due to adrenaline before exercise.
2. fast increase in HR due to increase in demand for oxygen.
3. plateus as supply meets demand of oxygen.
4. fast drop due to venous return.
5. slower decrease as HR returns to it’s pre exercise value.

Question 2

what is the effect of maximal intensity exercise on heart rate?

Answer 2

1. anticipatory rise - increase in HR due to adrenaline before exercise.
2. fast increase in HR due to increase in demand for oxygen.
3. slower increase as anaerobic and oxygen supply never reaches demand.
4. fast decrease post exercise due to drop in venous return.
5. slower recovery of HR than aerobic due to removal of more waste products (lactic acid.)

Question 3

what is the stroke volume exercise graph?

Answer 3

1. SV increases linearly with exercise intensity due to greater demand for oxygen from muscles.
2. SV plateaus towards maximal intensity as minimum time required to fully fill with blood.
3. SV drops is maximal intensity exercise as HR
   continues to fall so left ventricle can’t fully fill with blood before it is ejected again (cardiovascular drift.)

Question 4

what is your maximum heart rate?

Answer 4

220-age.

Question 5

what is the cardiac output exercise graph?

Answer 5

1. Q increases linearly with exercise intensity (HR and SV both increase.)
2. Q plateaus during maximal intensity exercise - SV decreases but HR continues to increase.

Question 6

what is the definition of vascular shunt?

Answer 6

the redistribution to where blood is required.

Question 7

what is the definition of sympathetic stimulation?

Answer 7

controls the diameter of the arterioles and pre-capillary sphincters.

Question 8

what is the definition of pre-capillary sphincters?

Answer 8

segments of smooth muscle which help direct blood flow into capillaries.

Question 9

describe vascular shunt during exercise?

Answer 9

1. chemoreceptors detect an increase in blood acidity, baroreceptors detect an increase in blood pressure, proprioceptors detect an increase in movement (thermoreceptors detect an increase in temperature.)
2. this informs the vascular control centre (V.C.C.)
3. the V.C.C increases it’s sympathetic stimulation of the arterioles and pre-capillary sphincters going towards organs, causing the arterioles and pre-capillary sphincters to vasoconstrict.

Question 10

describe vascular shunt during recovery?

Answer 10

1. chemoreceptors detect an increase in blood acidity, baroreceptors detect an increase in blood pressure and proprioceptors detect an increase in movement.
2. this information is sent to the vasomotor control centre (V.C.C.)
3. V.C.C decreases sympathetic stimulation of arterioles and pre-capillary sphincters going towards the organs, causing the arterioles and pre-capillary sphincters to vasodilate.
4. V.C.C decreases sympathetic stimulation of arterioles and pre-capillary sphincters going towards the working muscles, causing the arterioles and pre-capillary sphincters to vasoconstrict.

Question 11

what is the definition of venous return?

Answer 11

the return of blood to the right side of the heart via the vena cava.

Question 12

what are the five mechanisms of venous return?

Answer 12

1. pocket valves.
2. gravity.
3. smooth muscle.
4. skeletal muscle pump.
5. respiratory muscle pump.

Question 13

what is the definition of pocket valves?

Answer 13

prevents backflow of blood.

Question 14

what is the definition of gravity?

Answer 14

brings blood back to the heart from above the heart.

Question 15

what is the definition of smooth muscle?

Answer 15

constricts the veins pushing the blood upwards and towards the heart.

Question 16

what is the definition of skeletal muscle pump?

Answer 16

muscles surrounding the veins during exercise, squeeze the veins forcing the blood back to the heart.

Question 17

what is the definition of respiratory muscle pump?

Answer 17

due to increased breathing, pressure difference occur within the abdomen which increases blood movement.

Question 18

what is the blood vessel order?

Answer 18

aorta - arterioles - arteries - capillaries - venules - veins - vena cava

Question 19

benefits of a good venous return system?

Answer 19

• less chance of blood pooling.
• if more blood is being returned then more blood is being pumped to the muscles, enabling them to work for longer and prevent the build up of lactic acid.
• avoids fatigue.

Question 20

problems of venous return?

Answer 20

• blood pressure in the veins returning blood to the heart is 0.
• most of the cardiac output is in the legs so must travel against gravity back to the heart.

Question 21

what is neural control?

Answer 21

involves the sympathetic nervous system which is responsible for increasing heart rate.
involves the parasympathetic nervous system which is responsible for decreasing heart rate.

Question 22

what are the three factors affecting the regulation of heart rate?

Answer 22

1. neural factors.
2. hormonal factors.
3. intrinsic factors.