Muscles of the Thorax Relating to Respiratory Movements

Question 1

External intercostals

Answer 1

O: Inferior border of the rib above
I: Superior border of the rib below
A: Elevates rib cage, assists in forced inspiration
N: Intercostal nerves

Question 2

Internal intercostals

Answer 2

O: Superior border of the rib below
I: Inferior border of the rib above
A: Depress the rib cage, assists in forced expiration
N: Intercostal nerves

Question 3

Respiratory Diaphragm

Answer 3

O: Rib cage, sternum, and lumbar vertebrae
I: Central tendon
A: Prime mover of inspiration
N: Phrenic nerve