The<unk><unk>  (pl. rami) (Latin for branch) is the anterior division of a spinal<unk> . The<unk>  rami supply the antero-lateral parts of the trunk and the limbs. They are mainly larger than the dorsal rami. Shortly after a spinal<unk>  exits the intervertebral foramen, it branches into the dorsal<unk> , the<unk><unk> , and the<unk>  communicans. Each of these three structures carries both sensory and motor information. Each spinal<unk>  carries both sensory and motor information, via efferent and afferent<unk>  fibers - ultimately via the motor cortex in the frontal lobe and to somatosensory cortex in the parietal lobe - but also through the phenomenon of reflex. Spinal<unk> s are referred to as "mixed<unk> s". In the thoracic region they remain distinct from each other and each innervates a narrow strip of muscle and skin along the sides, chest, ribs, and abdominal wall. These rami are called the intercostal<unk> s. In regions other than the thoracic,<unk>  rami converge with each other to form networks of<unk> s called<unk>  plexuses. Within each plexus, fibers from the various<unk>  rami branch and become redistributed so that each<unk>  exiting the plexus has fibers from several different spinal<unk> s. One advantage to having plexes is that damage to a single spinal<unk>  will not completely paralyze a limb. There are four main plexuses formed by the<unk>  rami: the cervical plexus contains<unk>  rami from spinal<unk> s C1-C4. Branches of the cervical plexus, which include the phrenic<unk> , innervate muscles of the neck, the diaphragm, and the skin of the neck and upper chest. The brachial plexus contains<unk>  rami from spinal<unk> s C5-T1. This plexus innervates the pectoral girdle and upper limb. The lumbar plexus contains<unk>  rami from spinal<unk> s L1-L4. The sacral plexus contains<unk>  rami from spinal<unk> s L4-S4. The lumbar and sacral plexuses innervate the pelvic girdle and lower limbs.<unk>  rami, including the sinuvertebral<unk>  branches, also supply structures anterior to the facet joint, including the vertebral bodies, the discs and their ligaments, and joins other spinal<unk> s to form the lumbosacral plexus.
Ventral ramus of spinal nerve
Accelerator nerve
Long thoracic nerve
Frontopontine fibers
Type Ia sensory fiber
Anterior corticospinal tract
Cerebrospinal fibers
Lateral vestibulospinal tract