SAC 2

Question 0

result of acute respiratory responses in maximal exercise

Answer 0

ventilation (how much air breathed in and out in one minute) and diffusion (movement of molecules from an area of higher concentration to one of lower concentration)

Question 1

Acute responses to submaximal exercise in the first 5 seconds

Answer 1

Demand for oxygen increases so greater extraction of oxygen occurs from the blood. Therefore a-VO2 difference increases immediately as a result due to demand of mitochondria

Question 2

fuel use in fast twitch fibres when sprinting between 30-60 seconds

Answer 2

anaerobic= ATP-PC and anaerobic glycolysis

Question 3

Venous return to heart-how it is assisted?

Answer 3

The muscle pump- uses pumping action and muscle pressure to squash the veins forcing the blood to flow through them toward the heart. The valves in the vein stop the blood from flowing backwards.

Respiratory pump -During inspiration the diaphragm increases abdominal pressure, and the veins in the thorax and abdomen are emptied toward the heart.

Venoconstriction-Venoconstriction is a reflex controlled the CNS. It reduces the capacity of the venous system, forcing blood to be pushed toward the heart

Question 4

1-Compare the oxygen consumption of a sprinter and triathlete in a variable speed treadmill test.
A- indicate which is likely to be each athlete.

Answer 4

TRI- more oxygen consumption. S-less oxygen consumption-relies on Atp-PC

Question 5

1-Compare the oxygen consumption of a sprinter and triathlete in a variable speed treadmill test.
B-which one would be the steady state line on the graph-

Answer 5

straight line

Question 6

1-Compare the oxygen consumption of a sprinter and triathlete in a variable speed treadmill test.
C-what happens during oxygen deficit-

Answer 6

oxygen deficit is the difference between the total amount of oxygen required to perform the activity and actual amount of oxygen available to perform the activity until a steady state is reached

Question 7

1-Compare the oxygen consumption of a sprinter and triathlete in a variable speed treadmill test.
D-what occurs when lip is reached and how it contributes to fatigue in the muscle

Answer 7

when LIPis reached lactic acid is produced at a faster rate than it is able to be cleared and is a fatiguing by-product of physical activity as it continuously accumulates.
LA causes pain, inhibits the production of ATP, interferes with muscle contraction

Question 8

2-figure presented on arterio-venous oxygen difference

A-calculate the avo2 difference

Answer 8

oxygen concentration of arteriole blood (oxygenated blood) -the oxygen concentration of venous blood (deoxygenated blood)

Question 9

2-figure presented on arterio-venous oxygen difference

B-What happens to avo2 diff during exercise-

Answer 9

during exercise cells consume more oxygen , therefore,more oxygen goes from the arteries to the cells and less oxygen circulates the veins. This means that the arteriovenous oxygen difference increases with exercise.

Question 10

3-Graph used by athletes under different intensities over 40 minutes
A- what fuel other than blood glucose would be used by the athletes-

Answer 10

free fatty acids (fats) or glycogen (carbohydrates)

Question 11

3-Graph used by athletes under different intensities over 40 minutes
B-mechanisms involved in dealing with increased muscle temperatures-

Answer 11

Our bodys stimulates the sweat glands to produce sweat and increased blood flow to the skin combine to maintain a relatively constant body temperature.

Question 12

3-Graph used by athletes under different intensities over 40 minutes
C-venous return to the heart/ how it is assisted-

Answer 12

list the different mechanisms- respiratory pump, the muscle pump and venoconstriction

Question 13

4-complete a table with blank in stroke volume, heart rate and cardiac output.
A-calculate the answers of the blank areas

Answer 13

Q= Heart rate X stroke volume

Question 14

4 B-discuss acute respiratory responses that occur to an elite endurance athlete that contribute to oxygen supply

Answer 14

increased ventilation, tidal volume, respiratory rate or diffusion. Increased TV increases the amount of of oxygen taken in, increases RR increases how often oxygen is taken in, and these two combined increase the overall ventilation. Increased diffusion means that greater amounts of the oxygen taken in are transferred to the blood to be delivered to the working muscles.

Question 15

4 C-motor unit recruitment- what happens when different intensities of contraction are required?

Answer 15

A motor unit will contract maximally or not at all, depending on the strength of the stimulus. The amount of force generated in a muscle is directly related to the number of motor units recruited and the frequency of the messages sent to activate the motor units. A powerful movement (discuss throwing) requires the message to be sent to many motor units at an increased frequency to produce large force in the muscle. A more precise movement (shooting a goal in netball) requires fewer motor units to be recruited and the messages will not need to be so rapid as not many motor units are needed to produce the force required.

Question 16

5-graph on heart rate and lactate responses

A-Indicate where LIP occurs-

Answer 16

spot before the increase

Question 17

5-graph on heart rate and lactate responses

B-what happens in the muscle when LIP is exceeded and how it contributes to fatigue

Answer 17

LIP stands for the lactate inflection point and this occurs when H+ ions start to accumulate due to insufficient oxygen being supplied to enable them to be broken down. When this happens they accumulate quickly and fatigue sets in shortly after this

Question 18

6-why athletes should avoid large meals before competing or training. Discuss what can happen to adversely affect their performance

Answer 18

athletes can experience gastric discomfort and the digestion of food takes blood away from working muscles