Pec major/minor, serratus anterior, subclavius, omohyoid Flashcards
Omohyoid origin
Superior border of scapular near suprascapular notch
Omohyoid insertion
Inferior border of hyoid
Omohyoid action
depresses, retracts, and steadies hyoid
Omohyoid innervation
C1-C3 by a branch of ansa cervicalis
Subclavius origin
Junction of 1st rib and its costal cartilage
Subclavius insertion
Inferior surface of middle third of clavicle
Subclavius action
Anchors and depresses clavicle
Subclavius innervation
Subclavian nerve C5,6
Serratus anterior Origin
External surfaces of lateral parts of 1-8th ribs
Serratus anterior Insertion
anterior surface of medial border of scapula
Serratus anterior Action
Protracts scapula and holds against thoracic wall, rotates scapula
Serratus anterior innervation
Long thoracic nerve C5,6,7
Pec. Minor origin
3-5th ribs near their costal cartilage
Pec. minor insertion
Medial border and superior surface of coracoid process of scapular
Pec. minor action
Stabilizes scapula by drawing inferiorly and anteriorly against thoracic wall
Pec. minor innervation
Medial pectoral nerve C8, T1
Pec major origin
Clavicular head- anterior surface of medial half of clavicle
Sternocostal- anterior surface of sternum, superior 6 costal cartilages, and aponeurosis of external oblique muscle
Pec. major insertion
Lateral lip of intertubercular sulcus
Pec. major action
Adducts, medially rotates shoulder joint, draws on scapula anteriorly and posteriorly
Clavicular head alone- flexes shoulder joint
Sternocostal head alone- extends shoulder joint, when should is flexed
Pec. major innervation
Lateral and medial pectoral nerve, clavicular head C5,6 and sternocostal head C7, 8 T1
