Anterior Axioappendicular Muscles Flashcards
Pectoralis Major Insertion
1) Lateral lip of intertubercular sulcus of humerus
Pectoralis Major Origin
Clavicular head:
1) anterior surface of medial half of clavicle
Sternocostal head:
1) anterior surface of sternum
2) superior six costal cartilages
3) aponeurosis of external oblique muscle
Pectoralis Major Innervation
1) Lateral and medial pectoral nerves
2) Clavicular head (C5, C6)
3) Sternocostal head (C7, C8, T1)
Pectoralis Major Action
Adducts and medially rotates humerus
Draw scapula anteriorly and inferiorly
Acting alone: clavicular head flexes humerus and sternocostal head extends it from the flexed position
Pectoralis Minor Origin
1) 3rd-5th ribs near their costal cartilages
Pectoralis Minor Insertion
1) Medial border and superior surface of coracoid process of scapula
Pectoralis Minor Innervation
Medial pectoral nerve (C8, T1)
Pectoralis Minor Action
Stabilizes scapula by drawing inferiorly and anteriorly against thoracic wall
Subclavius Origin
1) Junction of 1st rib and its costal cartilage
Subclavius Insertion
1) Inferior surface of middle third of clavicle
Subclavius Innervation
Subclavian nerve (C5, C6)
Subclavian Action
Anchors and depresses clavicle
Serratus Anterior Origin
1) External surface of lateral parts of 1st-8th ribs
Serratus Anterior Insertion
1) Anterior surface of medial border of scapula
Serrats Anterior Innervation
Long thoracic nerve (C5, C6, C7)
Serratus Anterior Action
Protracts scapula and holds against thoracic wall
Rotates scapula
Deltoid Origin
1) Lateral third of clavicle
2) Acromion and spine of scapula
Deltoid Insertion
1) Deltoid tuberosity of humerus
Deltoid Innervation
Axillary nerve (C5, C6)
Deltoid Action
Clavicular (anterior) part flexes and medially rotates arm
Acromial (middle) part abducts arm
Spinal (posterior) part extends and laterally rotates arm
Supraspinatus Origin
1) Supraspinous fossa of scapula
Supraspinatus Insertion
Superior facet of greater tubercle of humerus
Supraspinatus Innervation
Suprascapular nerve (C4, C5, C6)
Supraspinatus Action
Initiates and assists deltoid in abduction of arm and acts with other rotator cuff muscles
Infraspinatus Origin
Infraspinous fossa of scapula
Infraspinous Insertion
Middle facet of greater tubercle of humerus
Infraspinatus Innervation
Suprascapular Nerve (C5, C6)
Infraspinatus Action
Laterally rotate arm
Help hold humeral head in glenoid cavity of scapula
Teres Minor Origin
Middle part of lateral boarder of scapula
Teres Minor Insertion
Inferior facet of greater tubercle of humerus
Teres minor Innervation
Axillary Nerve (C5, C6)
Teres Minor Action
Laterally rotate arm
Help hold humeral head in glenoid cavity of scapula
Teres Major Origin
Posterior surface of inferior angle of scapula
Teres Major Insertion
Medial lip of intertubercular groove of humerus
Teres Major Innervation
Lower subscapular nerve (C5, C6)
Teres Major Action
Adducts and medially rotates arm
Subscapularis Origin
Subscapular fossa (most of anterior surface of scapula)
Subscapularis Insertion
Lesser tubercle of humerus
Subscapularis Innercation
Upper and lower subscapular nerves (C5, C6, C7)
Subscapularis Action
Medially rotates and adducts arm
Helps hold humeral head in glenoid cavity of scapula
