Muscles of Thorax - Deep (O/I/A)

Question 1

External intercostals

Answer 1

O: Inferior border of rib above
I: Superior border of rib below
A: Pull ribs toward one another to elevate rib cage

Question 2

Internal intercostals

Answer 2

O: Superior border of rib below
I: Inferior border of rib above
A: Draw ribs together and depress ribcage

Question 3

Diaphragm

Answer 3

O: Inferior internal surface of ribs and sternum at sixth rib
I: Central Tendon
A: Mover of inspiration