Upper Extremity

Question 1

Biceps

Answer 1

Origin: Long head: supraglenoid tubercle of the scapula;
Short head: apex of coracoid process

Insertion: Tuberosity of radius

Innervation: C5 - C6 Musculocutaneous nerve

Function: Powerful flexor of the fore- arm at the elbow joint and supinator of the forearm; accessory flexor of the arm at the glenohumeral joint

Question 2

Brachialis

Answer 2

Origin: Anterior aspect of humerus (medial and lateral surfaces) and adjacent intermuscular septae

Insertion: Tuberosity of ulna

Innervation: C5 - C6 Musculocutaneous
nerve; (contribution of radial nerve to lateral part of muscle)

Function: Powerful flexor of the fore- arm at the elbow joint.

Question 3

Triceps

Answer 3

Origin: Long head - infraglenoid tubercle on scapula; Medial head - posterior surface of humerus
Lateral head - posterior surface of humerus

Insertion: Olecranon process of ulna

Innervation: C6 - C7 - C8 Radial nerve

Function: Extension of the forearm at the elbow;
Long head - accessory adductor and extension of the arm at the glenohumeral joint

Question 4

Brachioradialis

Answer 4

Origin: Proximal part of lateral suparepicondylar ridge of humerus and adjacent intermuscular septum

Insertion: Lateral sur- face of distal end of radius

Innervation: C5 - C6 Radial nerve

Function: Accessory flexor of el- bow joint when forearm is mid-pronated

Question 5

Wrist Flexors

Answer 5

Innervation: C6-C7-C8-T1

Function: Wrist flexion

Question 6

Wrist Extensors

Answer 6

Innervation: C6-C7-C8

Function: Wrist extension