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Flashcards in Scenario 27 Deck (6)
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1

What does balance receive inputs from?

Vestibular system, proprioception and vision

2

Where is the vestibular apparatus located?

Petrous part of the temporal bone

3

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

4

What does the membranous laryrinth consist of?

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

5

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

6

What happens if hairs are bent the other way?

Hyperpolarisation and decreased firing (bend towards shortest hair)