Ant. Axio-Appendicular and Scapulohumeral muscles Flashcards
Insertion of pectoralis major
Lateral lip of intertubercular sulcus (groove) of humerus
Origin of pectoralis major
Clavicular head: anterior surface of medial half of clavicle
Sternocostal head: anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique muscle
Innervation of pectoralis major
Lateral and medial pectoral nerves Clavicular head (C5 and C6) Sternocostal head (C7, C8, T1)
Main actions of pectoralis major
Adducts and medially rotates shoulder joint
Draws scapula anteriorly and inferiorly
Alone : clavicular head flexes shoulder joint and sternocostal head extends it from the flexed position
Origin of pectoralis minor
3rd-5th ribs near their costal cartilages
Insertion of pectoralis minor
Medial border and superior surface of coracoid process of scapula
Innervation of pectoralis minor
Medial pectoral nerve (C8, T1)
Action of pectoralis minor
Stabilizes scapula by drawing inferiorly and anteriorly against thoracic wall
Origin of subclavius
Junction of 1st rib and its costal cartilage
Insertion of subclavius
Inferior surface of middle third of clavicle
Innervation of subclavius
Subclavian nerve (C5, C6)
Action of subclavius
Anchors and depresses clavicle
Origin of serratus anterior
External surfaces of lateral parts of 1st-8th ribs
Insertion of serratus anterior
Anterior surface of medial border of scapula
Innervation of serratus anterior
Long thoracic nerve (C5, C6, C7)
Action of serratus anterior
Protracts scapula and holds against thoracic wall; rotates scapula
Origin of deltoids
Lateral third of clavicle
Acromion and spine of scapula
Insertion of deltoids
Deltoid tuberosity of humerus
Innervation of deltoid
Axillary nerve (C5, C6)
Action of deltoid
Clavicular part flexes and medially rotates shoulder joint
Acromial part abducts shoulder joint
Spinal part extends and laterally rotates shoulder joint
Origin of supraspinatus
Supraspinous fossa of scapula
Insertion of supraspinous
Superior facet of greater tubercle of humerus
Innervation of supraspinatus
Suprascapular nerve (C4, C5, C6)
Action of supraspinatus
Initiates and assists deltoid in abduction of shoulder joint and acts with other rotator cuff muscles
Origin of infraspinatus
Infraspinous fossa of scapula
Insertion of infraspinatus
Middle facet of greater tubercle of humerus
Innervation of infraspinatus
Suprascapular nerve (C5, C6)
Action of infraspinatus
Laterally rotate shoulder joint
Help hold humeral head in glenoid cavity of scapula
Origin of teres minor
Middle part of lateral border of scapula
Insertion of teres minor
Inferior facet of greater tubercle of humerus
Innervation of teres minor
Axillary nerve (C5, C6)
Action of teres minor
Laterally rotate shoulder joint
Help hold humeral head in glenoid cavity of scapula
Origin of teres major
Inferior part of lateral border of scapula and posterior surface of inferior angle of scapula
Insertion of teres major
Medial lip of intertubercular sulcus of humerus
Innervation of teres major
Lower subscapular nerve (C5, C6)
Action of teres major
Adducts and medially rotates shoulder joint
Origin of subscapularis
Subscapular fossa (most of anterior surface of scapula)
Insertion of subscapularis
Lesser tubercle of humerus
Innervation of subscapularis
Upper and lower subscapular nerves (C5, C6, C7)
Action of subscapularis
Medially rotates and adducts shoulder joint
Helps hold humeral head in glenoid cavity
