Sports science - circulatory responses to exercise

Question 1

What is the functions of the CV system?

Answer 1

• delivery
• removal
• transport
• maintenance
• protection (white blood cells)

Question 2

Is the CV system and open loop or closed loop system?

Answer 2

closed

Question 3

What are the components of the CV system?

Answer 3

• a fluid medium - BLOOD
• a system of channels - BLOOD VESSELS
• a pump - HEART

Question 4

What component of blood can you measure hydration by?

Answer 4

plasma

Question 5

What are the 2 main components of blood?

Answer 5

• plasma (55%)
• formed elements (45%)

Question 6

What is plasma made up of?

Answer 6

• water (90%)
• plasma proteins (7%)
• other (3%)

Question 7

What is the formed elements made up of?

Answer 7

• red blood cells (99%)
• white blood cells + platelets (1%)

Question 8

Does plasma volume increase or decrease after endurance training?

Answer 8

increase

Question 9

Does red blood cell volume increase or decrease after endurance training?

Answer 9

decrease

Question 10

Why does more plasma lead to easier blood flow?

Answer 10

• less viscous
• less resistant to flow

Question 11

What does the vascular system consist of?

Answer 11

• brain
• lungs
• heart
• arteries
• veins
• arterioles
• capillaries

Question 12

What is the role of arterioles?

Answer 12

determine blood flow to individual organs

Question 13

What is the importance of arterioles?

Answer 13

the redistribution of blood flow with exercise

Question 14

What type of vessels can arterioles be referred as?

Answer 14

resistance

Question 15

What type of vessels can the venous system be referred as?

Answer 15

capacitance

Question 16

What is venous pooling?

Answer 16

trouble with getting blood to the brain due to hydrostatic pressure

Question 17

Is blood in the venous system at high or low pressure?

Answer 17

low

Question 18

What is the role of a muscle pump?

Answer 18

• contraction of muscles pushes blood up the veins
• forces blood back to the heart under pressure

Question 19

How many pumps does the heart consist of?

Answer 19

2

Question 20

What are the names of the 2 heart pumps?

Answer 20

• pulmonary (right)
• systemic (left)

Question 21

List the roles of arteries and arterioles

Answer 21

• carry blood away from the heart
• determine redistribution of blood flow during exercise

Question 22

What is the role of capillaries?

Answer 22

exchange of oxygen and carbon dioxide and nutrients within tissues

Question 23

List the roles of veins and venules

Answer 23

• carry blood towards the heart
• skeletal muscle pump, increases the amount of venous blood returning to the heart during exercise

Question 24

How do you calculate cardiac output (Q)

Answer 24

Q = heart rate (HR) x stroke volume (SV)

Question 25

What are the 2 nervous systems?

Answer 25

- parasympathetic - sympathetic

Question 26

What is the role of the parasympathetic nervous system?

Answer 26

slows HR by inhibiting sinoatrial (SA) and atrioventricular (AV) node

Question 27

What is the role of the sympathetic nervous system?

Answer 27

increases HR by stimulating SA and AV node

Question 28

What factors affect stroke volume (SV)?

Answer 28

- increase force of contraction = increased SV - increase sympathetic nervous system activation . effects of circulating adrenaline and noradrenaline . direct stimulation of the heart muscle - increase end diastolic volume (EDV) . length-tension relationship . increase EDV = increased stretch of ventricular sarcomeres . increase stretch = increased force of contraction

Question 29

What are the major factors affecting EDV?

Answer 29

- increased activity of sympathetic nerves to veins - increased blood volume - increased skeletal muscle pump - increased inspiration movements

Question 30

What does cardiac output increase due to?

Answer 30

- increased HR - increased SV

Question 31

Why does oxygen delivery to exercising skeletal muscle increase?

Answer 31

- increased cardiac output - redistribution of blood flow from inactive organs to the contracting skeletal muscle

Question 32

Why does cardiac output increase as a linear function of oxygen during exercise?

Answer 32

- stroke volume reaches a plateau at approximately 40% of VO2 max - at work rates above 40% VO2 max, the rise in cardiac output is due to increase in HR alone