A&P Lab Muscles - shoulder and upper limb

Muscles crossing the shoulder joint : movements of the arm (humerus)

3 prime movers:

• Pectoralis major

• Latissimus dorsi

• Deltoid

Remaining 2:

• Teres major

• Coracobrachialis

Pectoralis major

Origin - clavicle, sternum, 1st 6 ribs

Insertion - greater tubercle humerus, lateral lip intertubercular sulcus

Action - prime mover arm flexion, adducts, medially rotates arm; bonus - extends flexed arm

Deltoid

Origin - clavicle, scapula (acromion and spine)

Insertion - humerus: deltoid tuberosity

Action - abduction of arm prime mover; bonus - flexor, extensor of arm

Muscles crossing the shoulder and elbow joints, movements of the arm and forearm

• Supraspinatus - insertion on superior face greater tubercle

• Infraspinatus - posterior face greater tubercle

• Teres minor - inferior to infraspinatus (post. face greater tubercle)

• Subscapularis (not seen!)- lesser tubercle (anterior humerus)

Latissiumus dorsi and teres major: synergists

Latissimus dorsi

Origin -

Insertion -

Action -

Subscapularis

Supraspinatus

Infraspinatus

Teres minor

Teres major

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