Henry Gray (18251861). Anatomy of the Human Body. 1918.
on or through the fibers of the Supinator, but beneath the Anconæus, and anastomoses with the radial collateral branch of the profunda brachii, the posterior ulnar recurrent and the inferior ulnar collateral.
The muscular branches (rami musculares) are distributed to the muscles along the ulnar side of the forearm.
The volar carpal branch (ramus carpeus volares; anterior ulnar carpal artery) is a small vessel which crosses the front of the carpus beneath the tendons of the Flexor digitorum profundus, and anastomoses with the corresponding branch of the radial artery.
The dorsal carpal branch (ramus carpeus dorsalis; posterior ulnar carpal artery) arises immediately above the pisiform bone, and winds backward beneath the tendon of the Flexor carpi ulnaris; it passes across the dorsal surface of the carpus beneath the Extensor tendons, to anastomose with a corresponding branch of the radial artery. Immediately after its origin, it gives off a small branch, which runs along the ulnar side of the fifth metacarpal bone, and supplies the ulnar side of the dorsal surface of the little finger.
The deep volar branch (ramus volaris profundus; profunda branch) (Fig. 528) passes between the Abductor digiti quinti and Flexor digiti quinti brevis and through the origin of the Opponens digiti quinti; it anastomoses with the radial artery, and completes the deep volar arch.
The superficial volar arch (arcus volaris superficialis; superficial palmar arch) (Fig. 527) is formed by the ulnar artery, and is usually completed by a branch from the a. volaris indicis radialis, but sometimes by the superficial volar or by a branch from the a. princeps pollicis of the radial artery. The arch passes across the palm, describing a curve, with its convexity downward.
Relations.The superficial volar arch is covered by the skin, the Palmaris brevis, and the palmar aponeurosis. It lies upon the transverse carpal ligament, the Flexor digiti quinti brevis and Opponens digiti quinti, the tendons of the Flexor digitorum sublimis, the Lumbricales, and the divisions of the median and ulnar nerves.
Three Common Volar Digital Arteries (aa. digitales volares communes; palmar digital arteries) (Fig. 527)arise from the convexity of the arch and proceed downward on the second, third, and fourth Lumbricales. Each receives the corresponding volar metacarpal artery and then divides into a pair of proper volar digital arteries (aa. digitales volares propriæ; collateral digital arteries) which run along the contiguous sides of the index, middle, ring, and little fingers, behind the corresponding digital nerves; they anastomose freely in the subcutaneous tissue of the finger tips and by smaller branches near the interphalangeal joints. Each gives off a couple of dorsal branches which anastomose with the dorsal digital arteries, and supply the soft parts on the back of the second and third phalanges, including the matrix of the finger-nail. The proper volar digital artery for medial side of the little finger springs from the ulnar artery under cover of the Palmaris brevis.
5. The Arteries of the Trunk. a. The Descending Aorta
The descending aorta is divided into two portions, the thoracic and abdominal, in correspondence with the two great cavities of the trunk in which it is situated
1. The Thoracic Aorta
The thoracic aorta(Fig. 530) is contained in the posterior mediastinal cavity. It begins at the lower border of the fourth thoracic vertebra where it is continuous with the aortic arch, and ends in front of the lower border of the twelfth at the aortic