University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

259

Pages:

3
Author:

Mariam A. A.

Nerves of the upper limb- Brachial Plexus Key Information The brachial plexus is the network of nerves supplying cutaneous, muscular, articular and vasomotor innervation to the upper limb. Identify the divisions of the brachial plexus including their peripheral branches. The divisions of the brachial plexus are divided into roots, trunks, divisions, cords and terminal branches. Roots Formed by the ventral (anterior) rami of spinal nerves C5-T1. The following branches should be noted: Dorsal Scapular Nerve Long Thoracic Nerve Spinal Roots General Course Function Anterior/ventral • arises just above the clavicle, • provides motor innervation to the root of spinal from the proximal part of the rhomboid major and rhomboid nerve C5 anterior ramus of C5 spinal minor muscles. nerve. • supplies the levator scapulae • It pierces the scalenus medius muscle along with the branches muscle and descends arising from spinal nerves C3 and between the levator scapulae C4 on one side and serratus • aids in elevation and adduction of posterior superior and the scapula toward the spinal scalenus posterior muscles on column the other side. Lateral branch of • These nerve roots commence • a motor nerve that provides branchial plexus deep to the scalenus medius innervation to the serratus and arises from muscle to form the trunk of the anterior muscle spinal nerves C5, long thoracic nerve. • Since the long thoracic nerve is C6, and C7 • Due to its relatively superficial the only nerve to innervate the location, almost the entire serratus anterior muscle, its course of the nerve is easily damage causes the paralysis of visible in cadavers. this muscle, resulting in a winged scapula. • Upon arising, the trunk of the nerve descends posteriorly to the brachial plexus, axillary artery and axillary vein, and anteriorly to the scalenus posterior muscle. • The long thoracic nerve courses distally and laterally, deep to the clavicle and superficial to the first and second ribs. • It continues along the anterior thoracic wall in the midaxillary line and ends on the superficial surface of the serratus anterior muscle. Trunks Identify the spinal roots of the following trunks of the brachial plexus. • Superior - C5 and C6 • • Middle - C7 Inferior - C8 and T1 Identify the following branches of the superior trunk. Spinal Roots Superior trunk brachial plexus General Course Suprascapular of Passes laterally across nerve lateral cervical region (posterior triangle of neck), superior to brachial plexus, then through the scapular notch inferior to superior transverse scapular ligament Nerve to Superior trunk, Descends posterior to subclavius receiving fibres from clavicle and anterior. C5, C6 and often C4 to brachial plexus and subclavian artery ; often giving an accessory root to phrenic nerve Function • Motor supply: supraspinatus muscle, infraspinatus muscle • Sensory supply: glenohumeral and acromioclavicular joints Subclavius and sternoclavicular joint (Accessory phrenic root innervates diaphragm)