The serratus posterior superior is a thin, quadrilateral muscle, situated at the upper and back part of the thorax, deep to the rhomboid muscles.
It arises by a thin and broad aponeurosis from the lower part of the ligamentum nuchae, from the spinous processes of the seventh cervical and upper two or three thoracic vertebrae and from the supraspinal ligament.
Inclining downward and lateralward it becomes muscular, and is inserted, by four fleshy digitations, into the upper borders of the second, third, fourth, and fifth ribs, a little beyond their angles.
The function of serratus posterior superior is to elevate second to fifth ribs, which aids deep inspiration.
Position of serratus posterior superior muscle (shown in red).
Serratus posterior superior muscles are labeled at center left and center right.
This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)
- Clinically Oriented Anatomy, 4th ed. Keith L. Moore and Arthur F. Dalley.
- Board Review Series: Gross Anatomy, 4th ed. Kyung Won Chung.
- Anatomy figure: 01:05-02 at Human Anatomy Online, SUNY Downstate Medical Center - "Intermediate layer of the extrinsic muscles of the back, deep muscles."