<P> The four mechanoreceptors in the skin each respond to different stimuli for short or long periods . </P> <P> Merkel cell nerve endings are found in the basal epidermis and hair follicles; they react to low vibrations (5--15 Hz) and deep static touch such as shapes and edges . Due to a small receptive field (extremely detailed info) they are used in areas like fingertips the most; they are not covered (shelled) and thus respond to pressures over long periods . </P> <P> Tactile corpuscles react to moderate vibration (10--50 Hz) and light touch . They are located in the dermal papillae; due to their reactivity they are primarily located in fingertips and lips . They respond in quick action potentials, unlike Merkel . They are responsible for the ability to read Braille and feel gentle stimuli . </P> <P> Lamellar corpuscles determine gross touch and distinguish rough and soft substances . They react in quick action potentials, especially to vibrations around 250 Hz (even up to centimeters away). They are the most sensitive to vibrations, and have large receptor fields . Pacinian reacts only to sudden stimuli so pressures like clothes that are always compressing their shape are quickly ignored . </P>

Includes nerve fibers to receptors in skin and sensory organs