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How do we hear?. Or, how do sound vibrations get converted for interpretation by our brain?. Mechanoreceptors. Responsive to small changes in mechanical force Hair cell : Long cilium called a… Series of microvilli decreasing in length called … Epithelial cell associated with sensory neuron.
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How do we hear? Or, how do sound vibrations get converted for interpretation by our brain?
Mechanoreceptors • Responsive to small changes in mechanical force • Hair cell: • Long cilium called a… • Series of microvilli decreasing in length called … • Epithelial cell associated with sensory neuron
Mechanoreceptors • Neuromast organ = hair cell + supportive cell + sensory neurons embedded in a… Fundamental component of: -Lateral line system – -Vestibular apparatus – -Auditory system – Fig. 17.31
Hair Cells • Respond to mechanical stimuli from … Stereocilia connected by tip links which are hypothesized to pull mechanically gated ion channels …
Vestibular Apparatus • Balancing organ that detects movements or changes in body position with respect to gravity • Filled with endolymph, surrounded by… • Semicircular canals with an ampulla at end of each • Two sac-like swellings: utriculus (utricle) and sacculus (saccule) • Most vertebrates have an extension of sacculus called the …
In ampullae of semicircular canals: In utriculus and sacculus: Cristae and maculae are expanded …
Function of Vestibular Apparatus • Semicircular canals detect angular acceleration (rotation) • Maculae detect linear velocity • In sacculus oriented … • In utricule oriented …
Function of Vestibular Apparatus • Informs CNS about orientation and whether in motion or not • But, balance and orientation maintained by integrating with inputs from visual system and proprioceptors • Play role in keeping eyes on single point while head moving
But how do we hear? • Lagena contains… • Goes to brain via … Perilymph Endolymph