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Flashcards in Scenario 27 Deck (6)
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What does balance receive inputs from?

Vestibular system, proprioception and vision


Where is the vestibular apparatus located?

Petrous part of the temporal bone


What does the bony labyrinth consist of?

Ant, lat and post semicircular canal, ampulla, fenestra cochleae (round window) or vestibuli (oval window), canal for facial nerve and cochlea


What does the membranous laryrinth consist of?

Utricle containing endolymph (high K low Na), surrounded by perilymph (high Na low K)


How do hair cells work?

Tallest hair is kinocilium with shorter following in a staircase creating the axis of polarity connected by tip links joining the hair to the upper layer. When the links are stretched the ion channels open and K travel into the cell from endolymph down concentration gradient. Depolarises the cell and Ca flows in causing NT release


What happens if hairs are bent the other way?

Hyperpolarisation and decreased firing (bend towards shortest hair)