Lung volumes - respiratory mechanics

Question 1

What is the equation for minute ventilation

Answer 1

Minute ventilation (VE) = Tidal volume (TV) x Frequency (f)

Question 2

What is minute ventilation

Answer 2

Volume of air inspired or expired per minute

Question 3

What is an average resting figure for minute ventilation

Answer 3

7.5 l/min

Question 4

What is an average figure for minute ventilation during maximal exercise

Answer 4

200 l/min

Question 5

What happens to minute ventilation before exercise

Answer 5

Increase due to anticipatory rise

Question 6

What happens to minute ventilation at the start of exercise

Answer 6

Rapid increase due to increased breathing frequency and TV

Question 7

What happens to minute ventilation during exercise

Answer 7

Rises steadily then reaches a plateau

Question 8

What happens to minute ventilation after exercise

Answer 8

Initial rapid, then gradual decrease to resting levels

Question 9

Why does VE increase until exercise concludes

Answer 9

Respiratory centre stimulated in response to high levels of Co2 and lactic acid

Question 10

What is tidal volume

Answer 10

Volume of air inspired/expired per breath

Question 11

What is the value for tidal volume at rest for all performers

Answer 11

0.5L

Question 12

What are 5 factors tidal volume is affected by

Answer 12

• Size of lungs
• Age
• Gender
• Fitness
• Respiratory conditions (e.g asthma)

Question 13

What is an average value for TV at exercise for untrained athletes

Answer 13

2.5 - 3.5L

Question 14

What is an average value for TV at exercise for trained athletes

Answer 14

3 - 3.5L

Question 15

What happens to tidal volume during exercise

Answer 15

Increases with intensity and plateaus during sub-max exercise. Short/shallow breaths near exhaustion

Question 16

What is breathing rate / frequency

Answer 16

Number of inspirations / expirations per minute

Question 17

What is a resting average for frequency

Answer 17

12-15 per min
11-12 per min in trained athlete

Question 18

What happens to frequency during exercise

Answer 18

Increases proportionate to intensity until maximal. Max f is 50-60 per min. Plateaus during sub-max, where O2 demand is met

Question 19

What type of process in inspiration

Answer 19

Active

Question 21

What sort of process is inspiration

Answer 21

Active

Question 22

What are the 2 main muscles involved in inspiration

Answer 22

External intercostals, diaphragm

Question 23

What occurs during inspiration

Answer 23

Diaphragm and external intercostals contract, so ribcage pushes up and out and volume of thoracic cavity increases (lungs expand) so pressure decreases

Question 24

What extra muscles are recruited during exercise inspiration

Answer 24

Sternocleidomastoid, pectoralis minor, scalenes

Question 25

What is the role of the extra muscles recruited during inspiration

Answer 25

Lift ribs further, so TV and VE increases

Question 26

What type of process is expiration at rest and during exercise

Answer 26

Passive at rest Active during exercise

Question 27

What occurs during expiration

Answer 27

Diaphragm and external intercostals relax so rib cage moves down and in, and thoracic cavity volume decreases and pressure increases (air leaves)

Question 28

What extra muscles are recruited during expiration

Answer 28

Internal intercostals, rectus abdominus

Question 29

What is the role of the extra muscles recruited during expiration

Answer 29

Internal intercostals - pull ribs down and in Rectus abdominus - push diaphragm up