Korean J Phys Anthropol.  2013 Sep;26(3):101-104. 10.11637/kjpa.2013.26.3.101.

Frequency and Quantity of the C7 Contribution to the Ulnar Nerve

• Hur MS
• Woo JS
• Kim HJ
• Lee KS

• KMID: 1488820
• DOI: http://doi.org/10.11637/kjpa.2013.26.3.101

Abstract

Many anatomists and clinicians who investigate the peripheral nerve concern about the composition of the spinal roots of each terminal nerve of the brachial plexus. From this viewpoint, the spinal root composition of the ulnar nerve is still unclear. Several anatomy textbooks describe that the ulnar nerve is composed of the ventral rami of the C8, T1 and often C7. There is no literature regarding the frequency and contribution quantity of C7 to the ulnar nerve. The purpose of present study was to determine frequency and contribution quantity of the C7 to the ulnar nerve. Fifty cadavers of brachial plexus were obtained from cadavers of Korean adults. The brachial plexus containing the ulnar nerve were extracted from the axilla and the extracted samples were immersed in Guanidine-HCl (0.2 M) for 2 weeks to soften the connective tissue around the nerve bundles. C7 was contributed to the ulnar nerve in all sides (100%). The numbers of the myelinated axons of C7 participating to the ulnar nerve was 1,452+/-429 (mean+/-S.D.). Thus the C7 can be considered as always participating component of the ulnar nerve, not often participation, although numbers of the myelinated axons of C7 was lesser than those of the C8, but similar to those of the T1. The results of the study provide a reference for accurate diagnosis and treatment regarding ulnar nerve injury due to various accidents.

Keyword

C7; Frequency; Quantity; Ulnar nerve

MeSH Terms

Adult
Anatomists
Axilla
Axons
Brachial Plexus
Cadaver
Connective Tissue
Humans
Myelin Sheath
Peripheral Nerves
Spinal Nerve Roots
Ulnar Nerve

Figure

• 

  Fig. 1. A photograph showing the C7 fascicles(arrow) constituting the ulnar nerve in the posterior aspect of the brachial plexus. C7 fasci-cles constituting the ulnar nerve branched out at the distal portion of the lateral cord. AN, axillary nerve, Lat C, lateral cord; MAN, medial antebrachial cutaneous nerve; MBN, medial brachial cutaneous nerve; MCN, musculocutaneous nerve; MDN, median nerve; Med C, medial cord; Post C, posterior cord; RN, radial nerve; UN, ulnar nerve.

Reference

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