Deepeer muscles of the neck and back in the act includes the following:
Rhomboideus, Rhomboideus Capitis, Splenius, Serratus Ventralis, Serratus
Dorsalis, and the Intercostals.
The Rhomboideus is a thick, large muscle below the [Trapezius muscles]. It
extends from the vertebral border of the scapula to the mid-dorsal line. Origin,
neural spines of the first four thoracic vertebrae, Insertion, vertebral border
of the scapula, Action, draws the scapula to the dorsal.
Rhomboideus capitis is the most cranial of the deeper muscles. It is
Clavotrapezius. Origin, superior nuchal line, Insertion, scapula, Action,
draws the scapula to the head and rotates it.
Splenius is the most superficical of all the deep muscles. It is a thin,
broad sheet of muscle undenreath the
Clavotrapezius and deflecting it. It is crossed also by the Rhomboideus
capitis. Origin, mid-dorsal line of the neckand fasica, Insertion, seuperior
nuchal line and atlas, Action, raises or turns the head.
Serratus Ventralis is exposed by cutting the wing-like
Latissimus Dorsi. The said muscle is covered entirely by adipose tissue.
Origin, from the first nine or ten ribs, and from part of the cervical
vertebrae. Insertion, vertebral border of the scapula, Action, draw scapula
forward, backward and against the body.
Serratus Dorsalis is medial to both the scapula and the Serratus Ventralis.
Origin, apoeurosis following the length of the mid-dorsal line, Insertion,
dorsal portion of the last ribs, Action, draws ribs craniad
The Intercostals is a set of muscles sandwiched between the ribs. They
interconnect ribs, and are therefore, the primary respiratory skeletal muscles.
It is divided into the External and the Internal subscapularis. Origin and
Insertion, ribs, Action, Pull front or back the ribs.