Serratus Posterior Superior Anatomy

Serratus Posterior Superior Muscle

Origin: Lower part of the nuchal ligament and the spinous processes of the vertebrae C7 through T3 and their corresponding supraspinous ligaments
Insertion: Superior borders and external surfaces of the second to fifth ribs, lateral to their angles
Actions: Elevation of the ribs during respiration
Innervation: Ventral rami of T2, T3, T4, T5
Blood Supply: Superior intercostal artery via the dorsal rami of the upper two posterior intercostal arteries

Primary Actions of the Serratus Posterior Superior

1. Forced inspiration

Agonists:

  • Levatores costarum brevis
  • Levatores costarum brevis longus

Antagonists:

  • Serratus posterior inferior
  • Transversus  abdominis

Anterior scalene and middle scalene assist with forced inspiration in some instances of labored breathing, such as during heavy exertion.

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