AOS2 Chapter 7 (Acute Responses)

Question 1

Acute response

Answer 1

• A short term physiological change to help meet the energy demands of exercise
• Body’s respiratory, cardiovascular and muscular systems go through series of changes to meet the new energy requirements

Question 2

Respiratory responses

Answer 2

• When exercise starts, the respiratory system aims to increase the volume of oxygen intake at the lungs

Question 3

Respiratory system

Answer 3

• The lungs and airways responsible for taking in oxygen and breathing out carbon dioxide

Question 4

Summary of respiratory responses

Answer 4

• Increased respiratory rate
• Increased ventilation
• Increased tidal volume
• Increased pulmonary diffusion

Question 5

Increased respiratory rate (Rf)

Answer 5

• Number of breaths per minute

Question 6

Increased ventilation (V)

Answer 6

• Volume of air breathed in per minute

- Rf times TV equals V

Question 7

Increased tidal volume (TV)

Answer 7

• Volume of air breathed per breath

Question 8

Increased pulmonary diffusion

Answer 8

• The gas exchange of gas transferred from the alveoli (lungs) to the capillary (blood) and vice versa
• An increased activation of alveoli results in more sites being available for gas exchange
• More sites for gas exchange, more pulmonary diffusion= increased levels of oxygen intake

Question 9

Cardiovascular responses

Answer 9

• When exercises starts, the aim of the cardiovascular system is to increase the volume of oxygenated blood delivered to the working muscles

Question 10

Cardiovascular system

Answer 10

• The heart, blood vessels and the blood itself which word, together to maintain blood flow to all parts of the body to allow it to survive

Question 11

Summary of cardiovascular system

Answer 11

• Increased heart rate
• Increased stroke volume
• Increased cardiac output
• Increased systolic blood pressure
• Redistribution of blood flow
• Increased venous return
• Increased a-VO2 difference
• Decreased blood volume

Question 12

Increased heart rate (HR)

Answer 12

• Number of beats per minute

Question 13

Increased stroke volume (SV)

Answer 13

• Volume of blood pumped per beat of the heart

Question 14

Increased cardiac output (Q)

Answer 14

• Volume of blood pumped by the heart per minute

- HR times SV equals Q

Question 15

Increased systolic blood pressure

Answer 15

• The pressure exerted by the blood against the arterial walls when the heart contracts

Question 16

Redistribution of blood flow

Answer 16

• Altering the percentage of cardiac output distributed around the body
• Vasodilation to the working muscles to increase blood flow
• Vasoconstriction to the inactive areas of the body to reduce blood flow (liver, kidneys etc)

Question 17

Increased venous return

Answer 17

• The blood returning to the heart via the venous system (veins)

Question 18

Increased a-VO2 difference

Answer 18

• The difference in concentration of oxygen in the arterial blood and the venous blood
• Increased at different intensities, more oxygenated blood, more oxygen uptake in muscle, more less oxygen concentrated blood leaving muscle= higher a-VO2 difference

Question 19

Decreased blood volume

Answer 19

• Total quantity of blood in the body (plasma and cellular)
• Decreasing body temp by cooling the body down via sweating means losing water component of blood
• Means reducing blood volume in the body and restricting blood flow

Question 20

Summary of muscular responses

Answer 20

• Increased motor unit recruitment
• Increased body temperature
• Increased oxygen uptake and consumption (VO2)
• Decreased energy substrate stores
• Increased metabolic by-products

Question 21

Increased motor unit recruitment

Answer 21

• The number and frequency of motor units recruited for muscle
• Increase in force production occurs either :
  • increase in the number of motor units stimulated
  • increase in the frequency of messages arrive to motor unit

Question 22

Increased muscle temperature

Answer 22

• The degree or intensity of heat present in the muscles
• During warm up, increasing muscle temp helps:
  • increase muscle elasticity
  • increase flexibility
  • reduce risk of injury
• During prolonged exercise, heat can become a fatigue factor (aerobic system), blood is redistributed to skin to cool off (sweat)

Question 23

Increased oxygen uptake and consumption (VO2)

Answer 23

• Volume of oxygen that can be taken up and used by the body

Question 24

Decrease energy substrate stores

Answer 24

• All available fuel sources within the muscle decrease when exercise is undertaken
• Duration and intensity of exercise determine the fuels and fibres used
• ATP, CP, Glycogen, Triglycerides

Question 25

Increased metabolic by-products

Answer 25

• Lactate is produced at rest and during exercise
• Able to remove lactate through oxidisation to convert it to glucose or glycogen
• Stays balance between lactate appearance and removal depending on duration and intensity of exercise
• If lactate exceeds LIP, production of blood lactate increases
• Can manage it better with endurance training