Hajszálreceptorok

Hajszálreceptorok, often translated as hair cell receptors or mechanosensory hair cells, are specialized sensory cells found in the inner ear of vertebrates, primarily responsible for hearing and balance. These cells possess a bundle of stereocilia, which are hair-like projections on their apical surface, giving them their name. The movement of these stereocilia, triggered by vibrations or fluid displacement, initiates an electrical signal that is transmitted to the brain, allowing for the perception of sound and spatial orientation.

In the auditory system, hair cells are located within the cochlea. Different regions of the cochlea are tuned to specific frequencies, meaning that hair cells in different locations respond to different pitches. When sound waves enter the ear, they cause vibrations that travel through the fluid-filled cochlea, bending the stereocilia of the hair cells. This bending opens ion channels, leading to depolarization and the release of neurotransmitters that signal the auditory nerve.

In the vestibular system, responsible for balance and spatial awareness, hair cells are found in the semicircular canals and the otolith organs (utricle and saccule). The semicircular canals detect rotational movements of the head, while the otolith organs sense linear acceleration and gravity. Fluid movement within these structures also deflects the stereocilia of hair cells, providing information about the body's position and movement. Damage to these hair cells, often due to aging, noise exposure, or ototoxic medications, can lead to hearing loss and balance disorders.