A hair plexus or root hair plexus is a special group of nerve fiber endings and serves as a very sensitive

mechanoreceptor A mechanoreceptor, also called mechanoceptor, is a sensory receptor that responds to mechanical pressure or distortion. Mechanoreceptors are innervated by sensory neurons that convert mechanical pressure into electrical signals that, in animals, ...

for touch sensation. Each hair plexus forms a network around a

hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...

and is a

receptor Receptor may refer to: * Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a ...

, which means it sends and receives nerve impulses to and from the

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...

when the hair moves. Endings of sensory nerve fibers which form a plexus around a hair follicle in hairy skin. They are mechanoreceptors conveying touch sensation. Specifically, crude touch and pressure sensation conveyed through the

spinocervical tract The spinocervical pathway is a four-neuron, fast-conducting, tactile/pressure pathway from the spinal cord to sensory cortex. It involves the primary sensory neuron in the dorsal root ganglion, second order cell in the dorsal horn, third order cell ...

, which is located in the posterior part of the

lateral funiculus The most lateral of the bundles of the anterior nerve roots is generally taken as a dividing line that separates the anterolateral system The spinothalamic tract is a part of the anterolateral system or the ventrolateral system, a sensory path ...

and terminates in the

lateral cervical nucleus The lateral cervical nucleus is a scattered nucleus located dorsally in the lateral funiculus in the first three cervical segments of the spine. The spinocervical and spinothalamic tracts synapse in the lateral cervical nucleus; the spinocervical ...

.Nolte, John. Nolte’s The Human Brain E-Book: An Introduction to its Functional Anatomy. Elsevier Health Sciences, 2015. The plexus acts as a receptor.

References

Neurophysiology {{neuroanatomy-stub