ORIGIN AND DITRIBUTION ANALYSIS OF THE BRACHIAL PLEXUS PERIPHERAL NERVES OF PACA (Agouti paca, LINNAEUS, 1766)

Abstract

The brachial plexus is a set of nerves originated in the cervicothoracic medular region and distributed in the thoracic limbs and inner thorax. The brachial plexus of eight pacas was dissected for study on the nerves origin and distribution. The suprascapular nerve went through the supra and infraspinal muscles and the subscapular gave off on the subscapular muscle. The axilar nerve was distributed on the teres major, subscapular, teres minor and deltoid muscles. The ulnar and the median nerves branched off on the forearm musculature, and the musculocutaneous branched on the coracobrachial, biceps brachial and brachial muscles. The radial nerve went through the triceps brachial, tensor fasciae latae and anconeus muscles. The long thoracic and the thoracodorsal nerves branched on the latissimus dorsi muscle, and the lateral thoracic gave off on the trunk cutaneous muscle. The cranial pectoral nerves branched on the deep pectoral muscle and the caudal pectoral nerves gave off on the superficial pectoral muscle. The brachial plexus of pacas is formed by 12 pairs of nerves presenting different origins, which arose from ventral roots from the fifth pair of cervical to the second pair of thoracic nerves, not occurring trunks or cords in those formation.
KEY  WORDS: Agouti paca, brachial plexus, distribution, nervous system.