Corpus: Superficial palmar arch
Synonym: superficial volar arch
Definition
The superficial palmar arch is an inconsistently occurring vascular arch in the palm. It is formed by the anastomosis of the distal portion of the ulnar artery with the superficial palmar branch of the radial artery.
Anatomy
The superficial palmar arch lies just below the palmar aponeurosis and the palmaris brevis muscle. It is embedded in loose connective tissue there, situated above the flexor retinaculum, the flexor tendons of the palm, the lumbrical muscles, as well as the flexor digiti minimi brevis muscle and the opponens digiti minimi muscle. Furthermore, it crosses the divisions of the median and ulnar nerves into their finger branches.
Branches
From the superficial palmar arch, 3-4 common palmar digital arteries arise. Each of them gives rise to two proper palmar digital arteries, supplying the two opposing sides of the fingers.
Topography
The apex of the superficial palmar arch projects to approximately the midpoint of the base of the third metacarpal bone.
Frequency
The closed vascular arch, the superficial palmar arch, occurs in only about 37 to 42 % of cases. The open variant is more common. The "typical" configuration described in textbooks, with a connection to the radial artery, is present in only about 35 % of individuals.
Mnemonic
Superficial palmar arch from the ulnar artery.