Brachial Plexus - Study Notes

BRACHIAL PLEXUSBrachial Plexus is a nerrous network, which supplies theupper limb, Starts from the neck, passes behind the claviclealong with axillary vessels through cervico-axillary canalor apex of axilla and enters the axillaIt is formed by ventral rami of lower 4 cervical nervesDivisions and Cords.and the TI nerves Consists of Roots, TrunksROOT FORMATIONPART- 1Formed by anterior primary rami of C5 to T1 andassisted by C4 and T2Roots are equal in sizeDIPANIAAR RAYSometimes, with contributions from the anterior primaryrami of 4 and T2.Pre Fixed Type PlexusPost Fixed Type PlexusBranch from e4 LargeBranch from es-ReducedBranch from -Frequently AbsentBranch from Ti- ReducedBranch from Ti- - LargedBranch from T2 Always PresentC4 Nerve (Nervous Furcula) -Divides to assist in the formationof Cervical and Brachial plexus. BRACHIAL PLEXUSTRUNK FORMATIONUPPER TRUNKC5 nerve supplemented by a branch from C4 uniteswith C6 (At lateral Border of Sclenus medius muscle)Form upper trunk.MIDDLE TRUNKCy Nerves runs independently (Behind Scelenusanterior M.) to form Middle thankLOWER TRUNKTj nerve, supplemented by a twig from theT2 here unite with the Cg (Behind Scelens conterior)form Lower trunk.TRUNKS DIVISIONPART-2 -DIPAMKAR RAY3 trunks thus formed descend downward and laterally and behindthe davicle, each trunk splits up into Anterion and Posteriordivisions in order to supply the muscles of flexor and extensorcompartments.FORMATION OF CORDLATERAL CORDFormed by union of Anterior division of upper andmiddle trunks. Contains fibres from C5,C6, C7.MEDIAL CORDContinuation of anterior division of Lower trunkcontains fibres from Cg and Ti.POSTERIOR CORDFormed by assemble of posterior divisions ofall 3 trunks. Conveys fibres from C5.C.C7,C8 andT,.Three their cords names enter the axilla and are arranged according toLateral and Posterior cards lie lateral to the artery.. Whereasaccording to 2nd and 3rd part of axillary arterythe medial cord passes behind the artery. BRACHIAL PLEXUSBranches of Brachial PlexusSUPRA CLAVICULAR BRANCHESINFRA CLAVICULAR BRANCHESARISING FROM NERVE ROOTARISING FROM NERVE TRUNKDorsal Scapular N-C5From upper trunk ofLong Thoracic N - C5,C6,CTBrachial plexus onlySupra-scapular NerveA branch to join Phrenic N- C5Nerve to sub-claviusMuscular Branches of longusColi and Scalen;PART -3DIMMORRAYFROM LATERAL CORDFROM MEDIAL CORDFROM POSTERIOR CORD3 Brandres5 Branches5 BrandresLateral PectoralMedial PectoralUlnar N (C7, , C8,T1)Upper Subscapular N.Muscedo-PuteneousLateral Root of Median N.Medial Root ofThoraso-dorsal N.Median N.Lower Subscapular NMedial Cuterrous Nof ARMAxillary N (C5,C6)Media Cuteneous NRadial N (C5,C,G,Cof forearmTi)