Robert Frysztak, PhD. Structure of the Human Body Loyola University Chicago Stritch School of Medicine THORAX MUSCLE TABLE PROXIMAL ATTACHMENT DISTAL ATTACHMENT MUSCLE INNERVATION MAIN ACTIONS BLOOD SUPPLY MUSCLE GROUP (ORIGIN) (INSERTION) Sternal half of clavicle, sternum to Pectoral branch of thoraco‐acromial 7th rib, cartilages of true ribs, Lateral lip of intertubercular sulcus of Flexes and adducts arm, rotates arm Pectoralis major Medial and lateral pectoral nerves artery, perforating branches of Pectoral/axilla region aponeurosis of external oblique humerus medially internal thoracic artery muscle Pectoral branch of thoraco‐acromial Outer surface of upper margin of ribs Lowers lateral angle of scapula and Pectoralis minor Coracoid process of scapula Medial pectoral nerve and intercostal lateral thoracic Pectoral/axilla region 3–5 protracts scapula arteries Costal surface of medial border of Protracts scapula and holds it against Serratus anterior Lateral surfaces of upper 8–9 ribs Long thoracic nerve Lateral thoracic artery Pectoral/axilla region scapula thoracic wall Xiphoid process, lower six costal Draws central tendon down and Pericardiacophrenic, musculophrenic, Diaphragm Converge into central tendon Phrenic nerve Posterior abdominal wall cartilages, L1–L3 vertebrae forward during inspiration superior and inferior phrenic arteries

Serratus posterior inferior Spinous processes of T11–L2 Inferior aspect of ribs 9–12 Ventral rami of lower thoracic nerves Depresses ribs Posterior intercostal arteries Superficial back Ligamentum nuchae, spinous Serratus posterior superior Superior aspect of ribs 2–4 Ventral rami of upper thoracic nerves Elevates ribs Posterior intercostal arteries Superficial back processes of C7–T3 Posterior intercostal arteries, collateral branches of posterior Supports intercostal spaces in Upper border of rib below rib of intercostal arteries, costocervical External intercostal Lower border of ribs Intercostal nerves inspiration and expiration, elevates Thoracic wall origin trunk, anterior intercostal branches ribs in inspiration of internal thoracic artery, musculophrenic artery

Muscular branches of anterior intercostal arteries, muscular Upper border of rib below rib of branches of posterior intercostal Innermost intercostal Lower border of ribs Intercostal nerves Elevates ribs Thoracic wall origin arteries, intercostal branches of internal thoracic and musculophrenic arteries, costocervical trunk branches

Muscular branches of anterior Prevents pushing out or drawing in of intercostal arteries, muscular Costal cartilage and edge of costal intercostal spaces in inspiration and branches of posterior intercostal Internal intercostal Lower border of ribs Intercostal nerves Thoracic wall groove of rib above rib of origin expiration, lowers ribs in forced arteries, intercostal branches of expiration internal thoracic and musculophrenic arteries, costocervical trunk branches Transverse processes of C7 and Subjacent ribs between tubercle and Dorsal ramus of lower thoracic Levator costarum Elevates ribs Posterior intercostal arteries Thoracic wall T1–T11 angle nerves Internal surface of lower ribs near Superior borders of 2nd or 3rd rib Posterior intercostal artery, Subcostal Intercostal nerves Depresses ribs Thoracic wall their angles below musculophrenic artery Internal surface of costal cartilages Anterior intercostal arteries, internal Transversus thoracis Posterior surface of lower sternum Intercostal nerves Depresses ribs and costal cartilages Thoracic wall 2–6 thoracic artery

07/16/2015