serratus posterior superior muscle

The serratus posterior superior muscle is a thin, quadrilateral muscle of the posterior thorax. It extends from the vertebrae to the ribs and aids in deep inspiration.

Summary

Gross anatomy

The serratus posterior superior muscle forms from a thin, broad aponeurosis which is attached to the lower part of the ligamentum nuchae, spinous processes of C7 to T3 vertebrae, and intervening supraspinous ligament. It passes inferolaterally and inserts onto the superior border, just lateral to the angles of the 2 to 5ribs .

Innervation

The serratus posterior superior muscle is innervated by the 2 to 5intercostal nerves .

Action

This muscle elevates the superior ribs which aids in inspiration.

Variant anatomy

  • may originate from the spinous processes of C7 and upper two or three thoracic vertebrae
  • may insert onto the 2 to 4 or 2 to 5 ribs