Inferior ulnar collateral artery Inferior ulnar collateral artery The inferior ulnar collateral artery (anastomotica magna artery) is a artery in the arm. It arises about 5 cm. above the elbow from the brachial artery. It passes medialward upon the Brachialis, and piercing the medial intermuscular septum, winds around the back of the humerus between the Triceps brachii and the bone, forming, by its junction with the profunda brachii, an arch above the olecranon fossa. 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, to anastomose with
Inferior mesenteric artery Inferior mesenteric artery In human anatomy, the inferior mesenteric artery, often abbreviated as IMA, is the third main branch of the abdominal aorta and arises at the level of L3, supplying the large intestine from the left colic (or splenic) flexure to the upper part of the rectum, which includes the descending colon, the sigmoid colon, and part of the rectum. Proximally, its territory of distribution overlaps (forms a watershed) with the middle colic artery, and therefore the superior mesenteric artery. The SMA and IMA anastomose via the marginal artery of the colon (artery of Drummond) and via Riolan's arcade