Respiratory System

Question 1

2 additional muscles involved in inspiration

Answer 1

• sternocleidomastoid

- pectoralis major

Question 2

2 additional muscles involved in expiration

Answer 2

• internal intercostals

- rectus abdominis

Question 3

Inspiration

Diaphragm & external intercostals…
2 additional muscles involved…

As a consequence of this

diaphragm...
rib cage moves...
volume of thoracic cavity...
pressure of air inside lungs...
air moves...

and so

rate of breathing…

Answer 3

Inspiration

contract with more force
sternocleidomastoid & pectoralis minor

As a consequence of this

flattens more
up & out more
increases more
decreases more
in

and so

increases

Question 4

Expiration

Diaphragm & external intercostals…
2 additional muscles involved…

As a consequence of this

diaphragm...
rib cage moves...
volume of thoracic cavity...
pressure of air inside lungs...
air moves...

and so

rate of breathing…

Answer 4

Expiration

relax more
internal intercostals & rectus abdominis

As a consequence of this

is pushed further up rib cage
down & in more
decreases more
increases more
out

and so

increases

Question 5

Mechanics of breathing during exercise

Answer 5

• additional muscles involved to move rib cage more during inspiration & expiration

The higher the exercise intensity the greater the force produced in these muscles

Question 6

Mechanics of breathing during recovery

Answer 6

• rate & depth of breathing remain elevated during recovery
• this keeps O2 volume breathed in & CO2 volume breathed out high to help recovery process
• rate & depth will return to their pre exercise values gradually

Question 7

Effect of O2 on gaseous exchange at the alveoli (during exercise)

Answer 7

• muscles using more O2
• deoxygenated blood returning to lungs has lower PPO2
• steeper diffusion gradient between alveoli & blood
• faster & more efficient gaseous exchange
• more O2 moves from alveoli & combines with haemoglobin in the lungs

Question 8

Effect of CO2 on gaseous exchange at the alveoli (during exercise)

Answer 8

• muscles producing more CO2 during exercise
• deoxygenated blood returning to lungs has higher PPCO2
• steeper diffusion gradient between blood & alveoli
• faster & more efficient gaseous exchange
• more CO2 moves from blood to alveoli to be expired