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"
Posterior interventricular artery right coronary artery (70%, known as right dominance). Alternately, the PIV can be a branch of the circumflex coronary artery (10%, known as left dominance) which itself is a branch of the left coronary artery. It can also be supplied by an anastomosis of the left and right coronary artery (20%, known as co-dominance). Variants have been reported. The anatomical position of the artery is not really posterior, but inferior. The terminology posterior is based on viewing the heart from the "Valentine" position, not by the heart's actual position in the body. Posterior interventricular artery In the coronary circulation, the