Afferent neurons are
pseudounipolar neurons that have a single process leaving the cell body dividing into two branches: the long one towards the
sensory organ, and the short one toward the central nervous system (e.g. spinal cord). These cells do have sensory afferent
dendrites, similar to those typically inherent in
neurons. They have a smooth and rounded cell
body located in the
ganglia of the peripheral nervous system. Just outside the
spinal cord, thousands of afferent neuronal cell bodies are aggregated in a swelling in the
dorsal root known as the
dorsal root ganglion. All of the axons in the dorsal root, which contains afferent nerve fibers, are used in the transduction of somatosensory information. Somatosensory receptors include senses such as pain, touch, temperature, itch, and stretch. For example, a specific muscle fiber called an
intrafusal muscle fiber is a type of afferent neuron that lies parallel to the
extrafusal muscle fibers thus functions as a stretch receptor by detecting muscle length.
Types Types of afferent fibers include the
general somatic, the
general visceral, the
special somatic and the
special visceral afferent fibers. Alternatively, in the
sensory system, afferent fibers can be classified by sizes with category specifications depending on if they innervate the skins or muscles. ==Function==