Arteries
The oxygenated blood reaches the right side via the brachiocephalic trunk and the left side directly from the aortic arch into the right or left subclavian artery. The subclavian artery merges into the axillary artery, which runs between the lower edge of the collarbone and the anterior axillary fold. Smaller branches lead to the musculature lying there, including the subscapular artery, which divides at the back of the shoulder blade and then supplies the shoulder or humeral head with blood.
From the front axillary fold, the axillary artery merges into the brachial artery. Together with the vein on the inside of the upper arm, it runs to the crook of the arm, where it divides into the stronger ulnar artery and the weaker radial artery. As it progresses, the brachial artery gives off the profunda brachii artery, which also supplies the triceps.
The collateral ulnar and inferior arteries also emerge from the brachial artery and supply the elbow joint. In the area of the elbow, the radial artery emerges from the interossea artery. On the side of the radius, the vessel passes between the muscles and to the carpal bones and finally forms the deep palmar arch (Arcus palmaris profundus).
During its course, the radial artery gives off branches to the thumb, the vascular network of the carpal bones, the back of the hand and the index finger. The ulnar artery also originates from the brachial artery in the area of the elbow. It runs on the side of the radius (ulna) between the flexor muscles of the forearm.
On the palm of the hand it forms the superficial hollow arch (Arcus palmaris superficialis). In doing so, it gives off a receding branch to the elbow joint (Arteria recurrens ulnaris). Further branches go to the carpal bones, the arterial network on the palm as well as on the back of the hand, a deep branch to the little finger and further small branches along the fingers.
