The inferior ulnar collateral artery (anastomotica magna artery) arises about 5 cm. above the elbow.

Course

It passes medialward upon the Brachialis, and piercing the medial intermuscular septum, winds around the back of the humerus

Humerus

The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....

 between the Triceps brachii and the bone, forming, by its junction with the profunda brachii

Profunda brachii

The arteria profunda brachii is a large vessel which arises from the lateral and posterior part of the brachial artery, just below the lower border of the Teres major.-Course:...

, an arch above the olecranon fossa

Olecranon fossa

The olecranon fossa is a deep triangular depression on the posterior side of the humerus, superior to the trochlea, in which the summit of the olecranon is received during extension of the forearm.-External links: *...

.

Branches and anastomoses

As the vessel lies on the Brachialis, it gives off branches which ascend to join the superior ulnar collateral: others descend in front of the medial epicondyle

Medial epicondyle

Medial epicondyle can refer to:* Medial epicondyle of the humerus * Medial epicondyle of the femur...

, to anastomose with the anterior ulnar recurrent.

Behind the medial epicondyle a branch anastomoses with the superior ulnar collateral and posterior ulnar recurrent arteries.