Muscles of Thorax Flashcards
Origin of the Diaphragm
Xphoid process
Costal Margin
Fascia over quadratus lumborum and psoas major
Vertebral bodies of L1-L3
Lateral & medial arcuate ligaments
Insertion of Diaphragm
Central tendon of diaphragm
Action of Diaphragm
Pushes abdominal viscera inferiorly increasing the volume of thoracic cavity (inhalation)
Origin of External Intercostals
Lower border of a rib within an intercostal space
Insertion of External Intercostals
Upper border of rib below, coursing downward and medially
Action of External Intercostals
Keeps the intercostal space from blowing out or sucking in during respiration
Origin of Innermost Intercostals
Upper border of a rib
Insertion of Innermost Intercostals
Fibers course up and medially to insert on the inferior margin of the rib above
Action of Innermost Intercostals
Keep the intercostal space from blowing out or sucking in during respiration
Origin of Internal Intercostals
Upper border of rib above
Action of Internal Intercostals
Keep the intercostal space from blowing out or sucking in during respiration
Insertion of Internal Intercostals
Lower border of rib above, coursing up and medially
Origin of Levatores Costarum
TVP’s of C7-T11
Insertion of Levatores Costarum
Rib below its origin, medial to the angle
Action of Levatores Costarum
Elevates rib
Origin of Serratus Posterior Inferior
Thoracolumnar fascia, SPs of T11-L2
Insertion of Serratus Posterior Inferior
Ribs 9-12, latearl to the angles
Action of Serratus Posterior Inferior
Pulls down lower ribs
Origin of Serratus Posterior Superior
Nuchal ligament, Sp’s of C7-T3
Insertion of Serratus Posterior Superior
Ribs 1-4, lateral to the angles
Action of Serratus Posterior Superior
Elevates the upper ribs
Origin of Subcostalis
Angles of ribs
Insertion of Subcostalis
Angle of a rib 2-3 ribs above origin
Action of Subcostalis
Compresses the intercostal space
