Cutaneous Innervation of the Upper Limb
Cutaneous Receptors
Sensory receptors in the skin help monitor the external environment.
Types of Sensory Receptors
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Thermoreceptor: detects major and minor changes in temperature. A specialised thermoreceptor is Bulboid corpuscle which senses cold temperatures
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Nociceptor: gives the impression of pain (response to damaging stimulus)
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Chemoreceptor: detects chemical stimuli, for example in olfaction
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Mechanoreceptor: responds to mechanical pressure. The skin has specialised structures for this, outlined in the next paragraph
Cutaneous Mechanoreceptors
A diagram of cutaneous mechanoreceptors can be found below.
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Free nerve endings: Respond to mechanical, noxios and thermal stimuli
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Ruffini ending: slowly adapting receptors - that is they detect pressure, touch and vibrations at low frequency
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Pacinian corpuscle: rapidly adapting mechanoreceptors - detect pressure and high frequency vibrations
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Merkel's discs: slowly adapting nerves that provide the CNS with continuous information about things in contact with the skin, so detect touch
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Meissner's corpuscle: rapidly adapting but sensitive mechanoreceptors that allow changes in things touching the skin to be detected