The Brachial Plexus & Shoulder

2 parts of the BP

-Anterior (flexor) flexor groups of the UE -Posterior (extensor) extensor groups of the UE

What is the Brachial Plexus?

-bundle of nerves -innervates the shoulder and upper extremity

Location of the Brachial Plexus

-deep in the lower part of the neck -exits from transverse processes of C-5 to T-1 -squeezes between the anterior and middle scalenes extends between the clavicle and the 1st rib into the axilla

In anatomical position, the coracobrachialis is deep to which two muscles?

-pectoralis major -anterior deltoid

Which shoulder movement would shorten the fibers of the teres major?

Adduction

What is the insertion of the teres major?

Crest of the lesser tubercle of the humerus

What movement shortens the fibers of the triceps brachii?

Elbow extension

Which shoulder movement would lengthen the anterior fibers of the deltoid?

Extension

Which joint is formed where the humerus and scapula meet

Glenohumeral

What is the insertion of the teres minor?

Greater tubercle of the humerus

What is the insertion of the latissimus dorsi?

Intertubercle groove of the humerus

What is an action of the infraspinatus?

Laterally rotate the shoulder

M O V E

Motor Output Ventral Efferent

S I D A

Sensory Input Dorsal Afferent

What muscle acts as a synergistic with pectoralis minor during anduction of the scapula?

Serratus anterior

What is the origin of the subscapularis?

Subscapular fossa of the scapula

Which muscle is sandwiched between the subscapular fossa and serratus anterior?

Subscapularis

Which rotator cuff muscle creates shoulder abduction?

Supraspinatus

Which bone of the shoulder region is the last of the skeletal system to completely develop?

The clavicle

What is the origin of the teres minor?

Upper two-thirds of lateral border of the scapula

What is an action of the trapezius?

Upwardly rotate the scapula