Human Anatomy, Part 2 - K. A. Diubenko, A. K. Kolomiitsev, Yu. B. Chaikovsky 2008

Special Part
Cardiovascular System, *systema cardiovasculare* — Special Part
Blood Vessels of the Systemic Circulation — Arteries of the Upper Limb — Ulnar Artery

The ulnar artery, a.ulnańs (Fig. 37), originates from the brachial artery deep within the cubital fossa (fossa cubiti), passes beneath the pronator teres Muscle (m.pronator teres), and courses toward the ulnar side of the forearm, where it lies in the ulnar sulcus (sulcus ulnaris) between the deep and superficial finger flexors on one side and the ulnar flexor on the other. The ulnar artery is projected onto the Skin from the midpoint of the ulnar crease to the pisiform bone. Near the pisiform bone, the ulnar artery enters the ulnar canal (canalis ulnaris), then emerges onto the palmar surface of the hand and contributes to The formation of the superficial palmar arch (arcus palmaris superficialis). The ulnar artery supplies Blood to the elbow joint, forearm, and hand.

Branches of the ulnar artery

1. A.recurrens ulnaris;

2. A.interossea communis;

3. R.carpalis palmaris;

4. R.carpalis dorsalis,

5. R.palmaris profundus.

1. The ulnar recurrent artery, a.recurrens ulnaris (Fig. 37), divides into an anterior branch (r.anterior) and a posterior branch (r.posterior), which ascend anterior and posterior to the medial epicondyle of the humerus, respectively, anastomosing with branches of the brachial artery (superior and inferior ulnar collateral Arteries, aa.collateralis ulnaris superior et inferior). Through this anastomosis, as well as the anastomoses between the branches of the deep brachial artery (middle collateral and radial collateral arteries, aa.collateralis media et a.collateralis radialis) and the radial recurrent branch (a.recurrens radialis), and the recurrent interosseous artery (a.interossea recurrens)—a branch of the posterior interosseous artery—an arterial network is formed around the elbow joint, known as the articular network of the elbow or rete articulare cubiti (see Fig. 36 A, B), which supplies the joint, skin, and Muscles of the elbow region.

2. The common interosseous artery, a.interossea communis (Fig. 39), runs toward the proximal margin of the interosseous membrane, where it divides into two branches: the anterior interosseous artery (a.interossea anterior) and the posterior interosseous artery (a.interossea posterior). The anterior interosseous artery pierces the membrane, reaches its posterior surface, and extends to the dorsal carpal network (rete саrріі dorsales). Along its course, it gives off branches to the BONES OF THE forearm and adjacent muscles. The posterior interosseous artery passes through the upper aperture of the interosseous membrane to reach the posterior surface, where it gives off the recurrent interosseous branch (a.interossea recurrens). It then courses between the deep and superficial layers of the extensors, reaching the wrist region, where it anastomoses with the anterior interosseous artery.

3. The palmar carpal branch, ramus carpalis palmaris, arises from the ulnar artery at the level of the styloid process, anastomoses with the corresponding branch of the radial artery and a branch from the anterior interosseous artery, and participates in the Formation of the palmar carpal network.

4. The dorsal carpal branch, ramus carpalis dorsalis, originates near the pisiform bone, passes beneath the ulnar wrist flexor (m.flexor саrріі ulnaris), reaches the posterior surface, and anastomoses there with the corresponding branch of the radial artery (a.radialis).

5. The deep palmar branch, ramus palmaris profundus, courses beneath the palmar flexor tendons and, together with the radial artery (a.radialis), forms the deep palmar arch (arcus palmaris profundus).

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Fig. 37. Arteries of the forearm and hand (right upper limb)

Fig. 37 A. Superficial palmar arch (arcus palmaris superficialis) and arteries of the right hand

Fig. 38. Variants of arterial arches and hand arteries according to M. A. Tikhomirov

The superficial palmar arch, arcus palmaris superficialis, in the majority of cases (Fig. 37) is the direct continuation of the main trunk of the ulnar artery*. The artery extends onto the palm, where in 60% of cases (V. V. Kovanov, 1983) it arches across the flexor tendons of digits II–IV and anastomoses with the superficial palmar branch of the radial artery (r.palmaris superficialis)**. The superficial palmar arch lies between the palmar aponeurosis and the digital flexor tendons, positioned 2–2.5 cm more distally than the deep arch (Fig. 37 A). It corresponds approximately to the mid-shaft level of the Metacarpal bones. Four common palmar digital arteries (aa.digitales palmares communes) arise from the superficial palmar arch and course distally; three of these run through the second, third, and fourth interosseous spaces, while the fourth runs along the ulnar side of the little finger. At the level of the metacarpal heads, the terminal segments of the common palmar digital arteries anastomose with the palmar metacarpal arteries (aa.metacarpea palmares) originating from the deep palmar arch. In the interdigital folds, each of these divides into two proper palmar digital arteries (aa.digitales palmares propńae), which run along the opposing sides of adjacent digits.

Based on the number of branches arising from the superficial palmar arch, the following anatomical variants are observed: a) three common palmar digital arteries arising most frequently; b) four common palmar digital arteries arising; c) two common palmar digital arteries arising (M. A. Tikhomirov, 1990) (Fig. 38).