Abstract
The origin of the nerve supply to coracobrachialis from the brachial plexus in apes was investigated in 4 arms from 4 chimpanzees, both arms of a gorilla and 4 arms from 4 gibbons. The general architecture of the brachial plexus was the same as in the human. In the apes examined, the nerves supplying this muscle could be classified into 2 groups: (1) distal branches arising from the musculocutaneous nerve, and (2) proximal branches arising in the region of the lateral cord. On the basis of their origin and course, the proximal branches were classified into 3 types, namely a deep ramus arising from the middle trunk and passing dorsal to the upper trunk, a medial ramus arising from the upper trunk in the lateral cord, and a superficial ramus arising from the ventral surface of the middle trunk or the root of the pectoral nerve. This classification also applies to branches to coracobrachialis in man. The 3 types of proximal branch often communicated with each other to supply coracobrachialis, whereas the proximal and distal branches were separated from each other spatially. This indicates that coracobrachialis possesses characteristics both of the pectoral girdle muscles and the flexor muscles of the upper arm.
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- Homma T., Sakai T. Ramification pattern of intermetacarpal branches of the deep branch (ramus profundus) of the ulnar nerve in the human hand. Acta Anat (Basel) 1991;141(2):139–144. doi: 10.1159/000147113. [DOI] [PubMed] [Google Scholar]
- Kida M. [Stratum-structure of the spinal nerves in the understanding of body structure]. Kaibogaku Zasshi. 1990 Apr;65(2):75–82. [PubMed] [Google Scholar]
- Klima M. Early development of the shoulder girdle and sternum in marsupials (Mammalia: Metatheria). Adv Anat Embryol Cell Biol. 1987;109:1–91. doi: 10.1007/978-3-642-72994-2. [DOI] [PubMed] [Google Scholar]
- Klíma M. Early development of the human sternum and the problem of homologization of the so-called suprasternal structures. Acta Anat (Basel) 1968;69(4):473–484. doi: 10.1159/000143096. [DOI] [PubMed] [Google Scholar]
- Koizumi M. [A morphological study on the coracobrachialis muscle]. Kaibogaku Zasshi. 1989 Feb;64(1):18–35. [PubMed] [Google Scholar]
- Nishimura R., Kusakabe A., Ounaka S., Mizoguti H. [Plexus brachialis of a gibbon (Hylobates agilis [F. Cuvier, 1821])]. Kaibogaku Zasshi. 1965 Oct;40(5):235–245. [PubMed] [Google Scholar]
- PREUSCHOFT H. [The nerves of the posterior extremity in the gorilla (Gorilla gorilla Savage and Wyman, 1847)]. Anat Anz. 1962 Feb 15;110:353–374. [PubMed] [Google Scholar]
- Parsons F G. The Muscles of Mammals, with Special Relation to Human Myology: A Course of Lectures delivered at the Royal College of Surgeons of England. J Anat Physiol. 1898 Jul;32(Pt 4):721–752. [PMC free article] [PubMed] [Google Scholar]
- Wood J. On Human Muscular Variations and their Relation to Comparative Anatomy. J Anat Physiol. 1867;1(1):44–59. [PMC free article] [PubMed] [Google Scholar]