Stretch-sensitive muscular-free nerve endings". The main purpose of a nociceptor is to respond to damage to the body by. "Neural mechanisms underlying the clasp-knife reflex in the cat. are free nerve endings located all over the body, including the skin.
Function of free nerve endings in skin skin#
For example, in hairy skin the peritrichial endings are most common, but Merkel’s discs and free nerve endings are also present. "Free nerve ending terminal morphology is fiber-type-specific for A delta and C fibers innervating rabbit corneal epithelium". The density and variety of receptors vary in different regions. These receptors are either encapsulated or unencapsulated, and the free nerve endings are usually unencapsulated dendrite. The diagram illustrates sensory nerve endings in the skin.
Mechanoreceptors are present in the superficial as well as the deeper layer of skin and near bone. "Thermal detection thresholds of Aδ- and C-fibre afferents activated by brief CO2 laser pulses applied onto the human hairy skin". The external stimuli are usually in the form of touch, pressure, stretching, sound waves, and motion. ^ Churyukanov M, Plaghki L, Legrain V, Mouraux A (2012).Evidence for two different heat transduction mechanisms in nociceptive primary afferents innervating monkey skin. ^ Rolf-Detlef Treede, Richard A.Meyer, Srinivasa N.Raja, James N.Campbell.In other words, they express polymodality. Thus, different free nerve endings work as thermoreceptors, cutaneous mechanoreceptors and nociceptors. Modality įree nerve endings can detect temperature, mechanical stimuli (touch, pressure, stretch) or danger ( nociception).
A delta type II fibers are fast-adapting while A delta type I and C fibers are slowly adapting. FNEs infiltrate the middle layers of the dermis and surround hair follicles.įree nerve endings have different rates of adaptation, stimulus modalities, and fiber types.ĭifferent types of FNE can be rapidly adapting, intermediate adapting, or slowly adapting. They penetrate the dermis and end in the stratum granulosum. They are the most common type of nerve ending, and are most frequently found in the skin. They function as cutaneous nociceptors and are essentially used by vertebrates to detect noxious stimuli that often result in pain.įree nerve endings are unencapsulated and have no complex sensory structures. Afferent in this case means bringing information from the body's periphery toward the brain. A free nerve ending ( FNE) or bare nerve ending, is an unspecialized, afferent nerve fiber sending its signal to a sensory neuron.
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