The plexus cervicalis can be seen as a cluster of nerves originating from the rami anteriores rami anteriores of nervi spinales C1-C4. A nerve loop known as the ansa cervicalis formed by branches of nervi spinales C1-C3, along with a contribution from the nervus hypoglossus can be seen in the superior aspect of the illustration. The ansa cervicalis gives off several motor branches to the m. geniohyoideus and mm. infrahyoidei. The n. phrenicus originates from C3-C5. It travels into the thoracic cavity (cavitas thoracis) and provides motor innervation to the diaphragma and sensory supply to the pericardium and diaphragma. The plexus cervicalis also provides contributions the n. accessorius, innervating the m. trapezius. The rami superficiales/cutanei of the plexus cervicalis (nn. occipitalis minor, auricularis magnus, transversus colli and supraclaviculares) innervate the skin of the neck, scalp and shoulder.
