Iliocostalis muscle

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Description:

This muscle has three subdivisions - the iliocostalis lumborum, iliocostalis thoracis, and iliocostalis cervicis

Origin of iliocostalis lumborum:
Posterior iliac crest and adjoining costal part of sacrum

Insertion of iliocostalis lumborum:
Tip of transverse processes of L1 to L4 and lower borders of ribs 6 to 12 near the angle

Origin of iliocostalis thoracis:
Upper borders of the angles of the lower six ribs

Insertion of iliocostalis thoracis:
Superior borders of the angles of the upper six ribs and the back of the transverse process of the seventh cervical vertebra

Origin of iliocostalis cervicis:
Superior margin of the angles of ribs 3 to 6 just medial to attachment of iliocostalis thoracis

Insertion of iliocostalis cervicis:
Posterior tubercles of transverse processes of C4 to C6

Actions:
Extend vertebral column

Nerve supply:
Dorsal rami of cervical, thoracic, lumbar, and sacral spinal nerves

Blood supply:
Branches of external carotid, posterior intercostal, and lumbar arteries