The anatomy of the brachial plexus of the dog

Abstract

ONE FIGUREThe dog is frequently subjected to traumatic injuries which are the result of being struck by automobiles and in many of these cases it is found that the brachial plexus is damaged with resultant paralysis of some of the muscles of the thoracic limb. It is, therefore, of clinical importance to study the nature and extent of such injuries in order to arrive at an intelligent prognosis. Such a study has been carried out and preliminary findings reported by Allani et al.( '49). Early in the course of this study it became apparent that a niore detailed knowledge of the normal plexus than has thus far been presented in the literature was required. Accordingly, a series of dissections of the plexus of normal dogs were made, and it is the purpose of this paper to record the observations made from these dissections.Ellenberger and Baum ( '47)' Bradley and Grahame ( '48) and Miller ( '48) all agree that the brachial plexus of the dog is formed from the ventral branches of the last three cervical and first two thoracic spinal nerves. Sisson and Grossman ('38) state that its origin is from the last 4 cervical and first thoracic spinal nerves. Howell ('37) states that the l Acknowledgment is made of the assistance given this "This study was aided in part by a faculty grant of M.D., deceased.

Lateral approach of the dog brachial plexus for ventral root reimplantation

“…When the ventral branch of C5 was incorporated into the brachial plexus, we cut it to allow a complete denervation of the cranial part of the plexus. 13,14 In particular, there was no contribution of the ventral branch of C8 to the suprascapular nerve in the dogs we used.…”

Neuroanatomy of the brachial plexus of the dog

“…Allam et al (1952) agree that the musculocutaneous nerve is formed entirely by two filaments from the cranial border of the seventh cervical nerve. Bradley and Grahame (1948) however, show the muscu locutaneous nerve receiving a large branch from the seventh cervical and a smaller branch from the caudal border of the eighth cervical trunk.…”

“…He further shows the subscapular receiving rami from both the sixth and seventh cervical nerves. Allam et al (1952), Bradley and Grahame (1948) and Ellenberger and Baum (1943) agree with Miller as to the origin and distribution of the suprascapular and subscapular nerves.…”

“…Miller (1934) further states that this type of plexus accompanies shoulder muscles that have undergone various adaptive changes coincidental with the lack of a clavicle. Allam et al (1952) found it convenient to designate three cords, superior, middle, and inferior. The superior cord is 2.…”

“…in length, and begins just distally to the anastomosing branches from cervical seven and thoracic one. The inferior cord as described by Allam et al (1952) originates from thoracic one and is located distad to the anastomosing branch from cervical eight and measures 1. 5 cm.…”