yogabook / muscles / intercostales interni

M. intercostalis internus

the profound part of the oblique abdominal muscles (but more superficial than the transversus abdominis), running ventrally from caudal-lateral to cranial-medial; the reduction in size of the thorax caused by it causes excess pressure in the lungs and leads to exhalation. It is therefore an expiratory respiratory muscle.
Origin: rib
Insertion: following rib
Innervation: Intercostal nerves 1-11, Th1 to Th12
Antagonists:
Movement: Exhalation

Intercostales interni (Linkmap)