6.7 the mechanism of breathing

Question 1

describe what is by the antagonistic interaction of the intercostal muscles.

Answer 1

one relaxes while one contracts

Question 2

describe the movement of the exchange system during inspiration. include the change in pressure & volume.

Answer 2

diaphragm muscles
- contracts & pull down

external intercostal muscles
- contracts, pulls ribcage out and up

internal intercostal muscles
- relaxes

volume of thorax increases & lung pressure decreases

Question 3

describe the movement of the exchange system during expiration. include the change in volume & pressure.

Answer 3

diaphragm muscles
- relaxes, pushed up

external intercostal muscles
- relaxes, ribcage moves down & in

internal intercostal muscles
- contracts

volume of thorax decreases & lung pressure increases

Question 4

how do you get pulmonary ventilation rate?

Answer 4

tidal volume * breathing rate