Serratus posterior superior

  • The serratus posterior superior (Latin: musculus serratus posterior superior) is a thin rectangular muscle that is located in the upper back and back part of the thorax. It lies deep to the rhomboid muscles

    Origin

    The serratus posterior originates from the inferior part of the nuchal ligament, and the cervical and thoracic parts of the vertebral column (usually C7 - T3). 

    Insertion

    The muscle fibers pass in an inferolateral direction and insert into ribs 2 to 5 slightly beyond their angles.

    Action

    The serratus posterior superior acts to elevate ribs 2 to 5, therefore, aiding in deep respiration.

    Innervation

    The intercostal nerves (2nd through 5th) innervate the serratus posterior superior.

    Blood supply

    The serratus posterior superior is supplied by the intercostal arteries.