Pectoral Region and Axilla Muscles Flashcards
Pectoralis Major Clavicular Head
Origin
-anterior surface of medial half of clavicle
Pectoralis Major
Insertion
-Lateral lip of intertubercular groove of humerus
Pectoralis Major
Innervation
- Lateral and medial pectoral nerves
- clavicular head (C5, C6)
- sternocostal head (C7, C8, T1)
Pectoralis Major
Action
–Horizontally adducts and medially rotates humerus.
Pectoralis Major Sternocostal Head
Origin
- anterior surface of sternum
- superior 6 costal cartilages
Pectoralis Major Clavicular Fibers
Action
-horizontally adduct humerus.
Pectoralis Major Sternocostal Fibers
Action
-horizontally adduct & extend humerus from a
flexed position.
Pectoralis Minor
Origin
-3rd to 5th ribs near their costal cartilages
Pectoralis Minor
Insertion
-Medial border and superior surface of coracoid process of scapula
Pectoralis Minor
Innervation
-Medial pectoral nerve (C8, T1)
Pectoralis Minor
Action
Anteriorly tilts & depresses scapula.
Subclavius
Origin
-Junction of 1st rib and its costal cartilage
Subclavius
Insertion
-Inferior surface of middle third of clavicle
Subclavius
Innervation
-Nerve to subclavius (C5, C6)
Subclavius
Action
-Stabilizes and depresses clavicle.
Serratus Anterior
Origin
-External and lateral surface of 1st – 8th ribs
Serratus Anterior
Insertion
-Anterior surface of medial border of scapula
Serratus Anterior
Innervation
-Long thoracic nerve (C5, C6, C7)
Serratus Anterior
Action
- Upwardly rotates & abducts scapula.
- Stabilizes scapula on thoracic wall.
Coracobrachialis
Origin
-Coracoid process of scapula
Coracobrachialis
Insertion
-Middle third of medial surface of humerus
Coracobrachialis
Innervation
-Musculocutaneous nerve (C5, C6, C7)
Coracobrachialis
Action
- Flexes & adducts humerus.
- Resists dislocation of glenohumeral joint.
