Template:Infobox Nerve Editor-In-Chief: C. Michael Gibson, M.S., M.D. ; Associate Editor(s)-in-Chief:
The brachial plexus is an arrangement of nerve fibres, running from the spine, specifically from above the fifth cervical vertebra to underneath the first thoracic vertebra (C5-T1). It proceeds through the neck, the axilla (armpit region) and into the arm.
- The brachial plexus is responsible for cutaneous and muscular innervation of the entire upper limb, with two exceptions: the trapezius muscle innervated by the spinal accessory nerve and an area of skin near the axilla innervated by the intercostobrachialis nerve.
- This function may be impaired by tumor growth of the Apical region of either Lung.
- Therefore, brachial plexus lesions can lead to severe functional impairment.
One can remember the order of brachial plexus elements by way of the mnemonic, "Read The Damn Cadaver Book" - Roots, Trunks, Divisions, Cords, Branches or - Roots, Trunks, Divisions, Cords, Collateral/Pre-terminal Branches, and (Terminal) Branches.
- The five roots are the five anterior rami of the spinal nerves, after they have given off their segmental supply to the muscles of the neck.
- These roots merge to form three Trunks:
- Superior or Upper (C5-C6)
- Middle (C7)
- Inferior or Lower (C8-T1)
- Each trunk then splits in two, to form six Divisions:
- Anterior division of the superior, middle and inferior trunks
- Posterior division of the superior, middle and inferior trunks
- These six divisions will re-group to become the three Cords. The cords are named by their position in respect to the axillary artery.
- The posterior cord is formed from the three posterior divisions of the trunks (C5-T1).
- The lateral cord is the anterior divisions from the upper and middle trunks (C5-C7).
- The medial cord is simply a continuation of the lower trunk (C8-T1).
- The branches are listed below. Most branch off of the cords, but a few branch (indicated in italics) directly off of earlier structures. The five in bold are considered "terminal branches".
|roots||dorsal scapular nerve||C5||rhomboid muscles and levator scapulae||-|
|roots||long thoracic nerve||C5, C6, C7||serratus anterior||-|
|superior trunk||nerve to the subclavius||C5, C6||subclavius muscle||-|
|superior trunk||suprascapular nerve||C5, C6||supraspinatus and infraspinatus||-|
|lateral cord||lateral pectoral nerve||C5, C6, C7||pectoralis major (by communicating with the medial pectoral nerve)||-|
|lateral cord||musculocutaneous nerve||C5, C6, C7||coracobrachialis, brachialis and biceps brachii||becomes the lateral cutaneous nerve of the forearm|
|lateral cord||lateral root of the median nerve||C5, C6, C7||fibres to the median nerve||-|
|posterior cord||upper subscapular nerve||C5, C6||subscapularis (upper part)||-|
|posterior cord||thoracodorsal nerve||C6, C7, C8||latissimus dorsi||-|
|posterior cord||lower subscapular nerve||C5, C6||subscapularis (lower part) and teres major||-|
|posterior cord||axillary nerve||C5, C6||anterior branch: deltoid and a small area of overlying skin
posterior branch: teres minor and deltoid muscles
|posterior branch becomes upper lateral cutaneous nerve of the arm|
|posterior cord||radial nerve||C5, C6, C7, C8, T1||triceps brachii, supinator, anconeus, the extensor muscles of the forearm, and brachioradialis||skin of the posterior arm as the posterior cutaneous nerve of the arm|
|medial cord||medial pectoral nerve||C8, T1||pectoralis major and pectoralis minor||-|
|medial cord||medial root of the median nerve||C8, T1||fibres to the median nerve||portions of hand not served by ulnar or radial|
|medial cord||medial cutaneous nerve of the arm||C8, T1||-||front and medial skin of the arm|
|medial cord||medial cutaneous nerve of the forearm||C8, T1||-||medial skin of the forearm|
|medial cord||ulnar nerve||C8, T1||flexor carpi ulnaris, the medial 2 bellies of flexor digitorum profundus, most of the small muscles of the hand||the skin of the medial side of the hand and medial one and a half fingers on the palmar side and medial two and a half fingers on the dorsal side|
Template:Spinal nerves Template:Brachial plexus
de:Plexus brachialis hr:Ručni splet id:Plexus brachialis he:מקלעת הזרוע no:Plexus brachialis sv:Plexus brachialis