Upper posterior cog muscle

Upper posterior cog , m. Serratus posterior superior, - a thin muscle, covered with a rhomboid muscle and forms the third layer of superficial muscles of the back.

It starts from the lower part of the nuchal ligament and the spinous processes of the two lower cervical and the two upper thoracic vertebrae. Its tufts are directed obliquely downward and laterally and are attached by four prongs to the outer surface of the II-V ribs, somewhat lateral to their corners.

Function : lifts the upper ribs, participating in the act of inspiration.

Innervation : nn. Intercostales (ThI-ThIV).

Blood supply : aa. Intercostales, cervicalis profunda.