It is an arterialarcade (arch) and thedominant vascularstructure of the palm.It is defined asthe anastomosesbetween thesuperficial branch ofthe ulnar artery andsuperficial palmarbranch of the radialArtery(usually).There are somevariations seen inthis too i.e. The archis variable.
SITUATION:• The convexity of the arch is directedtowards the fingers.• The distal point of the arch lies at thesame level as the distal border of thenareminence when the thumb is fully extended.
FORMATION: Medially: Normally,it begins as a terminalbranch of the ulnar artery on the flexorretinaculum distal to the pisiform bone. The arch: It then crosses the hook of thehamate bone and turns laterally deep to thepalmar aponeurosis. Laterally: It passes between abductorand flexor digiti minimi. It joins thesuperficial palmar branch of the radial artery.
RELATIONS: Superficially: Palmar Aponeurosis Palmaris brevis Deeply: Flexor digiti minimi Flexor tendons of fingers The lumbricals The digital branches of median nerve.
BRANCHES: The branches arise from the convexity of the arch. Themain branches are the 4 palmar digital arteries. The most medial is the PROPER PALMAR DIGITALBRANCH, supplying the medial side of the little finger. The other three called the COMMON PALMAR DIGITALBRANCHES, pass to the interdigital clefts. There, each receives the corresponding palmar metacarpalartery from the deep palmar arch. Then they divide into 2 PROPER PALMAR DIGITAL BRANCHESto the adjacent sides of two fingers. Thus, these branches supply the adjacent sides of littleand ring, ring and middle, middle and index fingers.THE PALAMR DIGITAL ARTERIES SUPPLY THE MEDIAL 3&½FINGERS.
VARIATIONS: The superficial palmar arch is formedpredominantly by the ulnar artery, with acontribution from the superficial palmarbranch of the radial artery. However, insome individuals the contribution from theradial artery might be absent, and insteadanastomoses with either the princepspollicis artery, the radialis indicisartery, or the median artery, the formertwo of which are branches from the radialartery.
ARTERIAL PATTERN IN THE PULP OF FINGERS: The two digital branchesrunning along the sides of thefingers ends in a rich arterialanastomoses at the pulp space onthe fingers.
DEEP PALMAR ARCH The deep palmar arch (or deep volar arch) isan arterial network found in the palm, deep to thesuperficial palmar arch. It provides a second channel connecting theulnar and radial arteries.FORMATION: The deep palmar arch is formed mainly by theterminal part of the radial artery, and is completedmaedially at the base of the fifth metacarpal bone bythe deep palmar branch of the ulnar artery.
RELATIONS: Superficially:• the oblique head of the adductorpollisis muscle,• the flexor tendons of the fingers,• the lumbricals of the hand. deeply:• the bases of the metacarpal bones,• the interossei of the hand.
BRANCHES: From its convexity i.e. from its distal side, thearch gives of three palmar metacarpal arteries, whichdistally in the 2nd, 3rd and 4th spaces, supply themedial 4 metacarpals, and terminate at the fingerclefts by joining the common digital branches of thesuperficial palmar arch. Dorsally, the arch gives off three (proximal)perforating arteries which pass through the medialthree interosseous spaces to anastomose with the dorsalmetacarpal arteries. The digital perforating arteries connect the palmardigital branches of the superficial palmar arch withthe dorsal metacarpal arteries. Recurrent branch arises from the concavity of thearch and pass proximally to supply the carpal bones andjoints, and ends in the palmar carpal arch.
APPLIED ASPECTS: The presence of variations in the superficial palmar arch is of surgical importance and whenever a surgery in done in the palmar aspect of hand,these variations if present, must be identified and approached accordingly.