Labyrinth

Question 1

Osseous labyrinth

Answer 1

defined by otic capsule

Question 2

otic capsule

Answer 2

dense layer of bone (perilymph between this capsule and membranous labyrinth)

Question 3

membranous labyrinth

Answer 3

perilymph between this and otic capsule, located inside the osseous labyrinth and contains endolymph

Question 4

Vestibule

Answer 4

Central chamber in the bone Contains: utricle, saccule, vestibular aqueduct, oval window, semicircular canals, cochlear canal

Question 5

Utricle

Answer 5

membranous labyrinth, balance organ, dealing with static orientation and linear acceleration

Question 6

saccule

Answer 6

membranous labyrinth, balance organs, dealing with static orientation and linear acceleration

Question 7

vestibular aqueduct

Answer 7

endolymphatic duct contains endolymphatic sac (in dura) leading to oval window

Question 8

semicircular canals

Answer 8

originate and terminate in vestibule, membranous semicircular ducts connected to utricle 3 canals in orthogonal planes (if head rotates can be combo of any 3 planes) crista ampullaris is located here and is involved in head rotation

Question 9

crista ampullaris

Answer 9

located in semicircular canals and involved in head rotation the quantity excites hair cells accessory structures determine head rotation –>sound doesn’t excite hair cells Receives NO information on linear acceleration

Question 10

Labyrinthe receptor organs

Answer 10

converter that results in neural code conveying sensory info to the brain

Question 11

kinocilium

Answer 11

made of microtubules, structures in cilia –> generate and make electric signals in cell and provide sensory signal kino=movement, but don’t actually move in inner ear determines polarity of cell

Question 12

stereocilia

Answer 12

not true cilia, don’t have ability to move on own, similar to microvilli but modified are rigid structures that can be bent have signaling/transduction function –>more numerous and more important! Protein (structural) actin core NOT microtubules

Question 13

Type I Vestibular Hair Cells

Answer 13

flask-shaped and have large chalis formed by one of sensory neurons, surrounded by afferent nerve channels efferent endings on the chalis (NOT soma)

Question 14

Type II Vestibular hair cells

Answer 14

more cylindrical shape afferent and efferent nerve endings ON soma

Question 15

Cupula

Answer 15

anchored on one end of crista ampullaris, but able to swing on other –> set up to be a boundary and needs to be deflected to move hair cell bundles fluid and walls of tube moves –>hair stays still because of mass and inertia depending on rotation of head and deflection of tubes

Question 16

otolithic membrane

Answer 16

composed of a gelatinous structure (density ~that of H2O otoliths located in utricular saccular maculae

Question 17

Otoliths

Answer 17

Detect linear acceleration and static rotation CaCO3 help to anchor structure, important can have physiological impact feel the gravitational attraction and structure gets shifted according to wall of vestibule (gravity) shearing is needed to activate hair cells signal varies due to strength of it constantly –> static head orientation