Thoracic Limb Brachial mm.

Only 2 are cranial and the rest are caudal group

Biceps brachii m. (cranial group)

O: supraglenoid tubercle of the scapula
I: ulnar and radial tuberosities

N: musculocutaneous n.
A: elbow flexion, shoulder extension

Internal tendon

inside biceps brachii m.

Biceps brachii m. (Eq.) - lacertus fibrosis

lacertus fibrosis is a tendon-like structure b/w the biceps and the extensor carpi radialis m.

Brachialis m. (cranial group)

O: lateral aspect of proximal 1/3rd of humerus
I: ulnar and radial tuberosities

N: musculocutaneous n.
A: elbow flexion

Triceps brachii m.

O: long head: caudal border of scapula; lateral head: tricipital line of humerus; accessory head: neck of humerus; medial head: crest of lesser tubercle
I: olecranon
A: shoulder flexion (long head only) and extension of elbow
N: radial n.

Long head of the triceps brachii m.

O: caudal border of scapula
I: olecranon
A: shoulder flexion (long head only) and extension of elbow
N: radial n.

Lateral head of the triceps brachii m.

O: tricipital line of humerus
I: olecranon
A: extension of elbow
N: radial n.

Medial head of the triceps brachii m.

O: crest of lesser tubercle
I: olecranon
A: extension of elbow
N: radial n.

Accessory head of the triceps brachii m. (Car., Bov.)

O: neck of humerus
I: olecranon
A: extension of elbow
N: radial n.

Tensor fascia antebrachii m.

O: fascia of lateral m. latissimus dorsi
I: olecranon
A: elbow extension
N: radial n.

Anconeus m.

O: lateral supracondylar crest, medial and lateral humeral epicondyles
I: lateral aspect of proximal ulna
A: elbow extension
N: radial n.