Hair plexus
Sensory nerve fiber
From Wikipedia, the free encyclopedia
A hair plexus or root hair plexus is a special group of nerve fiber endings and serves as a very sensitive mechanoreceptor for touch sensation.[1][2]
Hair contains a number of different types of nerve endings.[3] They are specialized for the detection of different kinds of stimuli and thus different types of neuron innervate these structures within the skin.[4][3] In particular there are neurons innervating the hair that detect deflection of the hair (i.e. to detect stroking), and pulling of the hair (i.e. noxious stimuli).[4][5]
The hair follicles are innervated by at least 5 classes of low threshold mechanical receptors.
They are mechanoreceptors conveying touch sensation with cell bodies located inside of either dorsal root ganglia or trigeminal root ganglia.[6] For most of the body (excluding the head and neck), crude touch and noxious stimuli from these receptors are further conveyed by the spinothalamic tract[7] whereas discriminative and light touch are conveyed to via the dorsal column medial lemniscus pathway.[8] The head and neck use pathways involving the spinal trigeminal nucleus.[9][10]
