Ulnar artery, a. ulnaris, represents one of the two terminal branches of the (larger) brachial artery. From the place of onset in the cubital fossa (against the neck of the radial bone), it fits under m. pronator teres, up to the middle third of the forearm goes sideways, deviating to the elbow side. In the lower two-thirds, it runs parallel to the ulna, first between the m. flexor digitorum superficialis and so on. flexor carpi ulnaris, in the lower third, due to the transition of muscles into tendons, its position becomes more superficial (sulcus ulnaris). At the radial side of the pea-shaped bone, the ulnar artery passes into canalis carpi ulnaris (spatium interaponeuroticum) and, passing on the palm, is part of the arcus palmaris superficialis.
Branches of the ulnar artery:
1. A. recurrens ulnaris, recurrent ulnar artery, gives two branches – rami anterior et posterior, which run in front of and behind the medial epicondyle, anastomosing with aa. collaterals ulnares superior et inferior. Thanks to these anastomoses, as well as the above anastomoses between the branches a. profunda brachii and a. radialis in the circumference of the elbow joint is obtained arterial network – rete articulare cubiti.
2. A. interossea communis, the common interosseous artery, goes to the interosseous membrane, at the proximal margin of which is divided into two branches:
a) a. interossea anterior to the anterior surface of the interosseous membrane reaches m. pronator quadratus, pierces the membrane and goes to the rear, where it ends in the rete carpi dorsale. At the beginning of your journey a. interossea anterior gives a. mediana (goes to the palm along with medianus), aa. diaphyseos radii et ulnae – to the bones of the forearm and rami musculares – to the surrounding muscles;
b) a. interossea posterior prohrdit through the upper opening of the interosseous membrane on the back side, gives a. interossea recurrens, lies between the superficial and deep extensor layers and anastomose in the wrist area with a. interossea anterior.
3. Ramus carpeus palmaris, the palmar carpal branch, goes towards the same-named branch of the radial artery, with which it anastomoses.