arm muscles

Biceps brachii action

Flexes arm and forearm, supinates forearm

Biceps brachii innervation

Musculocutaneuous

Biceps brachii origin

Long head: supraglenoid tubercle. Short head: coracoid process

Biceps brachii insertion

Radial tuberosity of radius

Coracobrachialis action

Flexes and adducts the arm

Coracobrachialis innervation

Musculocutaneous

Coracobrachialis origin

Coracoid process

Coracobrachialis insertion

Medial diaphysis of humerus

Brachialis action

Flexes forearm

Brachialis innervation

Musculocutaneous

Brachialis origin

Distal half of diaphysis of anterior humerus

Brachialis insertion

Radial tuberosity of radius

Triceps action

Extends forearm, extends arm at shoulder joint

Triceps brachii innervation

Radial

Triceps brachii origin

Long head: infraglenoid tubercle, lateral head: posterior, proximal diaphysis of humerus, medial head: most of posterior diaphysis of humerus

Triceps brachii insertion

Olecranon process

Anterior (flexor) compartment of arm

Biceps brachii, Coracobrachialis, Brachialis

Posterior (extensor) compartment of the arm

Triceps brachii only