This section is from the book "Anatomy Of The Arteries Of The Human Body", by John Hatch Power. Also available from Amazon: Anatomy of the Arteries of the Human Body, with the Descriptive Anatomy of the Heart.
The Inferior Profunda Artery arises nearly opposite the insertion of the coraco-brachialis muscle, and descends on the outside of the ulnar nerve, pierces with it the internal intermuscular ligament, and descends between this ligament and the triceps muscle to the interval between the internal condyle of the humerus and the olecranon process of the ulna, where it is covered by the ulnar nerve, and anastomoses with the posterior ulnar recurrent artery, and with branches from the anastomotic artery. In this course it supplies the integuments of the arm, and the biceps and triceps muscles. This artery may be small, absent, or double, or may arise in common with the superior profunda.
The Anastomotic Artery arises from the inside of the brachial, a little above the bend of the elbow; it then descends with a slight degree of obliquity inwards, anastomoses with the anterior ulnar recurrent, pierces the internal intermuscular ligament, and terminates between the internal condyle and olecranon process, in anastomosing with the inferior profunda artery and the posterior ulnar recurrent. The anastomotic artery varies considerably in size, being usually small, but sometimes as large as the inferior profunda.