Brachial plexus Brachial plexus The brachial plexus is a network of nerves formed by the ventral rami of the lower four cervical nerves and first thoracic nerve (C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in the neck, over the first rib, and into the armpit. It supplies afferent and efferent nerve fibers to the chest, shoulder, arm and hand. The brachial plexus is divided into five "roots", three "trunks", six "divisions" (three anterior and three posterior), three "cords", and five "branches". There are five "terminal" branches and numerous other "pre-terminal" or "collateral"
Brachial plexus block represent the limit below which the needle must not be directed (the pleural cavity and uppermost part of the lung are located at this level). Palpation or ultrasound visualization of the subclavian artery just above the clavicle provides a useful anatomic landmark for locating the brachial plexus, which is lateral to the artery at this level. Proximity to the brachial plexus can be determined using by elicitation of a paresthesia, use of a peripheral nerve stimulator, or ultrasound guidance. Compared to the interscalene block, the supraclavicular block — despite eliciting a more complete block of the median, radial ulnar and