Anat Cell Biol.  2014 Mar;47(1):77-80. 10.5115/acb.2014.47.1.77.

Multiple unilateral variations in medial and lateral cords of brachial plexus and their branches

• Goel S
• Rustagi SM
• Kumar A
• Mehta V
• Suri RK

• KMID: 2168860
• DOI: http://doi.org/10.5115/acb.2014.47.1.77

Abstract

During routine dissection of the upper extremity of an adult male cadaver, multiple variations in branches of medial and lateral cords of brachial plexus were encountered. Three unique findings were observed. First, intercordal neural communications between the lateral and medial cords were observed. Second, two lateral pectoral nerves and one medial pectoral nerve were seen to arise from the lateral and medial cord respectively. The musculocutaneous nerve did not pierce the coracobrachialis. Finally, the ulnar nerve arose by two roots from the medial cord. Knowledge of such variations is of interest to anatomists, radiologists, neurologists, anesthesiologists, and surgeons. The aim of our study is to provide additional information about abnormal brachial plexus and its clinical implications.

Keyword

Intercordal communication; Musculocutaneous nerve; Thoracic nerves; Ulnar nerve

MeSH Terms

Adult
Anatomists
Brachial Plexus*
Cadaver
Humans
Male
Musculocutaneous Nerve
Thoracic Nerves
Ulnar Nerve
Upper Extremity

Figure

• 

  Fig. 1 Right axillary region showing. AA, axillary artery; AV, axillary vein; ILPN, inferior lateral pectoral nerve; LC, lateral cord of brachial plexus; LTA, lateral thoracic artery; PMi, pectoralis minor muscle; PMj, pectoralis major muscle; SLPN, superior lateral pectoral nerve; SSA, subscapular artery; STA, superior thoracic artery; TAA, thoracoacromial artery.

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  Fig. 2 Right axillary region showing. AA, axillary artery; AV, axillary vein; BB, biceps brachii muscle; LC, lateral cord of brachial plexus; LTA, lateral thoracic artery; MC, medial cord of brachial plexus; MCN, musculo cutaneous nerve; MN, median nerve; MPN, medial pectoral nerve; PMi, pectoralis minor muscle; PMj, pectoralis major muscle; STA, superior thoracic artery; TAA, thoracoacromial artery; 1, cranial branch of MPN; 2, caudal branch of MPN.

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  Fig. 3 Right arm anteromedial aspect showing. AA, axillary artery; BB, biceps brachii muscle; b1, short transverse branch of MCN to coracobrachialis; b2, long branch of MCN to coracobrachialis; b3, branch of MCN to biceps brachii; b4, branch of MCN to biceps brachii and brachialis; CB, coraco brachialis muscle; MCN, musculocutaneous nerve; MN, median nerve; PMj, pectoralis major muscle; SSA, subscapular artery.

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  Fig. 4 Right axillary region. AA, axillary artery; LC, lateral cord of brachial plexus; LR, lateral root of median nerve; LTA, lateral thoracic artery; MC, medial cord of brachial plexus; MCN, musculocutaneous nerve; MCNA, medial cutaneous nerve of arm; MCNF, medial cutaneous nerve of forearm; MN, median nerve; MPN, medial pectoral nerve; MR, medial root of median nerve; PMi, pectoralis minor muscle; SSA, subscapular artery; STA, superior thoracic artery; TAA, thoracoacromial artery; UN, ulnar nerve; #, caudal neural communication; *, cranial neural communication, a and b, two roots of origin of ulnar nerve.

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