mechanoreceptory

Mechanoreceptors are sensory receptors that detect mechanical energy such as pressure, stretch, itch, vibration, and movement. They convert physical forces into electrical signals (receptor potentials) that are transmitted to the nervous system via sensory neurons. Mechanoreception enables touch, proprioception, hearing, and balance, and operates across the skin, muscles, joints, and inner ear.

Cutaneous mechanoreceptors in the skin include Meissner corpuscles and Pacinian corpuscles (both rapidly adapting) and Merkel discs and Ruffini endings (slowly adapting). Meissner detects light touch and textures at glabrous skin; Pacinian responds to high-frequency vibration; Merkel discs encode sustained pressure and texture; Ruffini endings sense skin stretch. Hair follicle receptors detect hair movement. Proprioceptors such as muscle spindles and Golgi tendon organs provide information about limb position and muscle force. In the inner ear, cochlear hair cells and vestibular hair cells transduce mechanical vibrations and head movements.

Mechanotransduction relies on mechanically gated ion channels, including the Piezo family and, in the auditory system, transduction channels at the tips of stereocilia. Deflection of stereocilia opens channels, allowing cations to enter and produce receptor potentials, which drive neurotransmitter release and action potential firing in afferent neurons. Receptor responses vary with adaptation properties, enabling detection of both fleeting and sustained stimuli. Disorders of mechanoreception can arise from peripheral nerve damage, diabetes, or aging, affecting touch, proprioception, or balance.