The brachial plexus is a network of nerves formed by the anterior 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.
The cervical plexus is a network of nerve fibres that supplies innervation to some of the structures in the neck and trunk. It is located in the posterior triangle of the neck, halfway up the sternocleidomastoid muscle, and within the prevertebral layer of cervical fascia.
The cervical plexus innervates muscles of the neck and areas of skin on the head, neck and chest. The deep branches innervate muscles, while the superficial branches supply areas of skin. A long branch (C4; nervus phrenicus) innervates muscles of the diaphragm.
The lumbar plexus is a web of nerves (a nervous plexus) in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the divisions of the first four lumbar nerves (L1-L4) and from contributions of the subcostal nerve (T12), which is the last thoracic nerve.
sacral plexus a plexus arising from the ventral branches of the last two lumbar and first four sacral spinal nerves. solar plexus see solar plexus. tympanic plexus a network of nerve fibers supplying the mucous lining of the tympanum, mastoid air cells, and pharyngotympanic tube.