lecture 23-ear

Question 1

what is contained in the middle ear

Answer 1

auditory ossicles
openings
muscles

Question 2

what is contained in the inner ear

Answer 2

baby labyrinth
membrane labyrinth
vestibular organ

Question 3

define auricle

Answer 3

contained in outer ear

pinna of the ear and auditory canal

Question 4

define external auditory meatus

Answer 4

outer 1/3 is composed of elastic cartilage
inner 2/3 is composed of bone
lined with stratified squamous epithelium with sebaceous and ceruminous glands

Question 5

what is the tympanic membran

Answer 5

separates the external auditory canal from middle ear

core is formed from vascularized, innervated connective muscle (this is why it hurts if we get something in our ear)

Question 6

what are the parts of the auditory ossicle

Answer 6

malleus (hammer): attaches to tympanic membrane and articulates with incus
incus (anvil): intermediate bone between the stapes and malleus
stape: third bone in series, shaped like stirrup, inserts into oval window

Question 7

what is the oval window

Answer 7

opening into scala vestibuli

Question 8

what is the round window

Answer 8

membrane-covered region at the end of the scala tympani

Question 9

what are the muscles of the middle ear

Answer 9

tensor tympani: inserts into the malleus
stapedius: inserts on the stapes
these both dampen the vibration of loud sounds that go to the auditory ossicles

Question 10

what is the baby labyrinth

Answer 10

carved into the bone at the base of the skull

consists of semicircular canals, cochlea, scala vestibuli, scala tympani

Question 11

what is the membranous labyrinth

Answer 11

lines the baby labyrinth

complex system of membraneous structures embedded within the chambers of the bony labyrinth

Question 12

what is the vestibular organ

Answer 12

located in inner ear
primarily assocated with equilibrium and balance
patches of sensory structures that respond to changes in position
consists of maculae of the saccule and utricle

Question 13

define otolithic membrane

Answer 13

gelatinous layer containing calcium carbonate crystals called otoliths that overlies the epithelium
stereocilia of the vestibular hair cells are embedded in this gelatinous layer
movement of the head displaces the otolithic membrane and causes a sensory impulse

Question 14

what is the cupla

Answer 14

gelatinous layer similar to the otolithic membrane but does not have otoliths (in cristae ampullares of semicircular ducts)

Question 15

what does movement of fluid do to the cupula

Answer 15

displaces it and causes the sterocilia to bend

Question 16

what does the auditory organ of the inner ear consist of

Answer 16

cochlear duct, scala vestibuli, scala tympani, vestibular membrane, basillar membrane, stria vascularis, organ of corti

Question 17

what forms the floor and roof of the cochlear duct

Answer 17

vestibular membrane: roof

basilar membrane: floor

Question 18

what does the stria vascularis do

Answer 18

forms the lateral aspect of the duct

participates in the formation of the endolympth

Question 19

where is the organ of corti located

Answer 19

lies on the basilar membrane

Question 20

what is contained in the outer ear

Answer 20

auricle, external auditory meatus, tympanic membrane