· extends in continuity with tendon of PL
· from distal border of flexor retinaculum
· fans out towards fingers
· divides into 4 slips
· each slip gives off superficial fibres to skin
· slip divides into 2 bands
· inserted into
· deep transverse ligament of palm
· bases of P1
· flexor sheaths
· aponeurosis thin over thenar and hypothenar eminences
· septum passes dorsally from each border of central part
· medial septum to 5th MC
· lateral septum to 1st MC
· thin septum passes from middle of aponeurosis
· intermediate septum to 3rd MC
Middle
· lies between medial and intermediate septae
· dorsal wall formed by 3-4 and 4-5 intermetacarpal spaces
· contains
· flexor tendons of fingers III, IV and V
· their lumbricals
Thenar
· lies between lateral and intermediate septae
· dorsal wall formed by I-2 and 2-3 intermetacarpal spaces
· contains
· FPL
· flexor tendon of II
· its lumbrical
· radial side
· tubercle of scaphoid
· ridge of trapezium
· ulnar side
· pisiform
· hook of hamate
· deep extension on radial side
· bridges groove of trapezium
· transmits FCR
· superficial extension on ulnar side
· called superficial part of retinaculum
· attaches to pisiform
· forms Guyon’s canal
· transmits ulnar n & a (nerve on ulnar side)
· crossed by
· ulnar n & a
· PL (fuses with it)
· palmar cutaneous branch of median n
· superficial palmar branch of radial a
· contains 9 tendons and median n
· 4 x FDS, 4 x FDP, FPL
· finger flexor tendons lie on ulnar side
· tendons of FDS
· lie in 2 planes
· III and IV superficial
· II and V deep
· tendons of FDP
· lie in one plane deep to FDS tendons
· only tendon to II separated
· others separate in palm
· FDS & FDP tendons share common synovial sheath
· tendons invaginated into sheath from radial side
· FPL in own sheath
· 3 web spacs
· extend from skin edge to MCP jts (4 cm)
· contain
· superficial and deep transverse MC ligaments
· digital vessels and nerves
· intrinsics
Superficial transverse metacarpal ligament
· lies beneath palmar skin
· across free margins of webs
· continued along sides of fingers
· supports fold of web
· digital NV bundle lies immediately deep to ligament
· lumbrical tendon lies beneath vessels
Deep transverse metacarpal ligament
· joins palmar ligaments of MCP jts
· lies 3 cm proximal to superficial ligament
· interosseous tendons lie on dorsal side
· lumbrical tendons lie on palmar side
· lacks superficial and deep ligaments
· deep fascia lies across web
· beneath it lie
· transverse head of AdP
· 1st dorsal IO
· from space emerge
· princeps pollicis
· radialis indicis
· attached to dermis
· part of panniculus carnosus
· lies across base of hypothenar eminence
· supplied by superficial branch of ulnar n
· only muscle it supplies
· ulnar a continues from Guyon’s canal
· divides into superficial and deep branches
Superficial branch
· forms superficial palmar arch
· may become continuous with superficial branch of radial a
· this branch passes superficial to or through thenar mm
· often not a complete arch (made up only of ulnar a)
· arch lies superficial to everything in palm
· just deep to palmar aponeurosis
· lies across palm at level of distal border of outstretched thumb web
· gives off 4 branches
· digital a to ulnar side of little finger
· common palmar aa to web spaces 2-3, 3-4 and 4-5
· each common palmar a divides into proper digital a
· thumb and radial side of index finger supplied by branches of radial a
Deep branch
· joins terminal branch of radial artery
· to form deep palmar arch
Radial artery
· leaves lower border of radius
· curves across snuffbox
· passes into hand between 2 heads of 1st dorsal interosseous
Branches
Digital
· gives off 2 branches to thumb and index (rest supplied by ulnar a)
1. arteria radialis indicis
· passes between 1st dorsal interosseous and AdP
· supplies radial side of II
2. princeps pollicis
· passes along MC I
· divides into 2 digital branches
Superficial arch
· may give off superficial palmar branch
· to form part of superficial palmar arch
Deep palmar arch
· terminal branch passes into palm between oblique and transverse heads of AdP
· forms deep palmar arch
· anastomoses with deep branch of ulnar a
· usually complete
· runs across palm 1 cm proximal to superficial arch
· deep branch of ulnar n runs in concavity of arch
· gives off
· 3 palmar metacarpal aa that comunicate with common palmar aa around MC head
· perforating aa that communicate with dorsal metacarpal aa
Superficial branch
· runs distally beneath palmaris brevis
· supplies palmaris brevis
· divides into 2 digital branches
· one for ulnar side of litle finger
· one for 4-5 cleft and adjacent fingers
· nerve to 4-5 cleft sends branch to median digital n
Deep branch
· accompanied by deep branch of ulnar a
· passes deeply
· between AbDM and FDM
· perforates ODM
· crosses palm in concavity of deep palmar arch
· supplies
· all 3 hypothenar muscles
· ulnar 2 lumbricals
· all interossei
· AdP
· FPB (often)
Muscular branch
· syn. recurrent, thenar
· first branch of median n
· arises distal to flexor retinaculum
· may arise in carpal tunnel and pierce retinaculum
· curves laterally and proximally
· crosses and supplies
· FPB
· AbPB
· OP
Digital branches
· divides into 5 common palmar digital branches
· may first divide into medial and lateral branches
· thumb nerves may arise from common stem
· 2 branches pass to thumb
· one for radial side crosses in front of tendon of FPL
· 1 branch passes to radial index finger
· also supplies 1st lumbrical
· 2 branches pass to 2-3 and 3-4 clefts
· divide into proper digital nn for adjacent sides of fingers
· nerve for 2-3 cleft supplies 2nd lumbrical
· nerve for 3-4 cleft receives twig from ulnar n
· tendon perforates flexor retinaculum
· lies in groove of trapezium
· passes deep to tendon of FPL
· inserted into bases of index and middle MCs
· may give slip to scaphoid
· inserted into pisiform
· pisiform is morphologically a sesamoid
· extends insertion of FCU into
· hamate via pisohamate ligament
· MC V by pisometacarpal ligament
· runs along radial border of forearm
· covered by APL and EPB
· inserted into radial styloid