This section is from the book "Anatomy Of The Arteries Of The Human Body", by John Hatch Power. Also available from Amazon: Anatomy of the Arteries of the Human Body, with the Descriptive Anatomy of the Heart.
The Superficial palmar arch of arteries corresponds nearly to the semicircular fold on the palm of the hand which circumscribes the muscles of the thumb: it is, in general, smaller than the deep arch, and its convexity, which looks downwards and inwards, is nearer to the phalanges: anteriorly it is covered by the integuments and palmar aponeurosis: posteriorly it lies on the flexor tendons, and the divisions of the median nerve as they pass to the fingers. In the fore-arm we see the radial and ulnar arteries lying between their corresponding nerves; but in the hand the order is reversed, the nerves being situated between the arches of arteries.
The branches of the superficial palmar arch arise both from its concavity and from its convexity.
The Branches from the Concavity of the Superficial Palmar Arch are small and numerous: they supply the tendons of the flexor muscles, the lumbricales, lower portion of the median nerve, the annular ligament, and parts in the immediate vicinity; and anastomose with branches of the radial and ulnar arteries.