By Rate of Adaptation
Cutaneous mechanoreceptors can also be separated into categories based on their rates of adaptation. When a mechanoreceptor receives a stimulus, it begins to fire impulses or action potentials at an elevated frequency (the stronger the stimulus, the higher the frequency). The cell, however, will soon "adapt" to a constant or static stimulus, and the pulses will subside to a normal rate. Receptors that adapt quickly (i.e. quickly return to a normal pulse rate) are referred to as "phasic". Those receptors that are slow to return to their normal firing rate are called "tonic". Phasic mechanoreceptors are useful in sensing such things as texture or vibrations, whereas tonic receptors are useful for temperature and proprioception among others.
- Slowly adapting: Slowly adapting mechanoreceptors include Merkel and Ruffini corpuscle end-organs, and some free nerve endings.
- Slowly adapting type I mechanoreceptors have multiple Merkel corpuscle end-organs.
- Slowly adapting type II mechanoreceptors have single Ruffini corpuscle end-organs.
- Intermediate adapting: Some free nerve endings are intermediate adapting.
- Rapidly adapting: Rapidly adapting mechanoreceptors include Meissner corpuscle end-organs, Pacinian corpuscle end-organs, hair follicle receptors and some free nerve endings.
- Rapidly adapting type I mechanoreceptors have multiple Meissner corpuscle end-organs.
- Rapidly adapting type II mechanoreceptors (usually called Pacinian) have single Pacinian corpuscle end-organs.
Read more about this topic: Mechanoreceptor, Types, Cutaneous
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