Group C nerve fiber

Group C nerve fiber
C fiber not labeled, but substantia gelatinosa of Rolando is Rexed lamina II, labeled at upper left.
Dorlands/Elsevier	f_05/12360696

C-fibers are part of the human sensory system, a type of sensory fiber, part of the nervous system responsible for processing sensory information.

They are unmyelinated and as a result, have a slower conduction velocity than other nerve fibers, lower than 2 m/s. These fibers are associated with chronic or dull pain. C-fibers are associated with sensations of warmth, as well as mechanical and chemical stimuli. The density for cold receptors in the skin is greater than the density of warm-receptors (by a factor of 5). It is thought that most or all C fibers are nociceptors (responding only to noxious stimuli).

C fibers terminate in the substantia gelatinosa of Rolando.

See also

• Free nerve ending
• Nociceptor
• Pain
• Sensory neuron
• Thermoreceptor
• B fiber

Histology: nervous tissue
Neurons (gray matter)	soma, axon (axon hillock, axoplasm, axolemma, neurofibril/neurofilament), dendrite (Nissl body, dendritic spine) types (bipolar, pseudounipolar, multipolar, pyramidal, Purkinje, granule)
Afferent nerve/Sensory nerve/Sensory neuron	GSA, GVA, SSA, SVA, fibers (Ia, Ib or Golgi, II or Aβ, III or Aδ or fast pain, IV or C or slow pain)
Efferent nerve/Motor nerve/Motor neuron	GSE, GVE, SVE, Upper motor neuron, Lower motor neuron (α motorneuron, γ motorneuron)
Synapses	neuropil, synaptic vesicle, neuromuscular junction, electrical synapse - Interneuron (Renshaw)
Sensory receptors	Free nerve ending, Meissner's corpuscle, Merkel nerve ending, Muscle spindle, Pacinian corpuscle, Ruffini ending, Olfactory receptor neuron, Photoreceptor cell, Hair cell, Taste bud
Glial cells	astrocyte, oligodendrocyte, ependymal cells, microglia, radial glia
Myelination (white matter)	Schwann cell, oligodendrocyte, nodes of Ranvier, internode, Schmidt-Lanterman incisures, neurolemma
Related connective tissues	epineurium, perineurium, endoneurium, nerve fascicle, meninges