origin:  lower border of ribs

insertion:  upper border of rib below

intercostal n.

elevates ribs in inspiration

origin:  lower border of ribs

insertion:  upper border of rib below

intercostal n.

elevate interchondral part of ribs

depresess ribs in expiration

origin:  lower border of ribs

insertion:  upper border of rib below

intercostal n.

elevates ribs

origin:  posterior surface of lower sternum and xiphoid process

insertion:  inner surface of costal cartilages 2-6

intercostal n.

depresses ribs

origin:  inner surface of lower ribs near angles

insertion:  upper borders of ribs 2 or 3 below

intercostal n.

elevates rib

origin:  transverse processes of T7-T11

insertion:  subjacent ribs b/t tubercle and angle

dorsal primary rami of C8-T-11

Elevates ribs