the mechanics of breathing

Question 1

what muscles are used during inspiration at rest?

Answer 1

diaphragm
external intercostals

Question 2

what muscles are used during inspiration during exercise?

Answer 2

diaphragm
external intercostals
sternocleidomastoid
scalenes
pectoralis major

Question 3

what muscles are used during expiration at rest?

Answer 3

passive: diaphragm and intercostals just relax

Question 4

what muscles are used during expiration during exercise?

Answer 4

abdominals
internal intercostals