Special Senses - Ear

Question 0

What supports the auditory meatus

Answer 0

Laterally - cartilage , medially temporal bone

Question 1

Where does sound go from the Pinna

Answer 1

It goes from the pinna to the auditory meatus to the tympanic membrane

Question 2

What lines the auditory meatus

Answer 2

A think skin that also lines the tympanic membrane. It has modified sweat glands that secrete waxy cerumen

Question 3

What is in the middle layer of the tympanic membrane

Answer 3

The stroma has two layer of collagen fibers

Question 4

Are the collagen fibers of the tympanic membrane radial or ciruclar

Answer 4

Some are both

Question 5

What covers the internal layer of the tympanic membrane

Answer 5

Simple epithelium like the rest of the middle ear

Question 6

What is the pars tensa

Answer 6

tough part of the tympanic membrane where is attached the middle ear bone the malleus

Question 7

What s the pars flaccida?

Answer 7

A part of tympanic membrane with less collagen and thus reduces stiffness. where most eardrum ruptures occur.

Question 8

What lines the external part of the tympanic membrane?

Answer 8

A thin layer of epidermis (like the auditory meatus) but it does not have hair or glands.

Question 9

What bone is the middle ear in

Answer 9

it is essentially just a space within the temporal bone

Question 10

What kind of cell lines the middle ear

Answer 10

simple squamous mostly (some simple cuboidal)

Question 11

What connects the middle ear to the inner ear

Answer 11

Oval and Round windows

Question 12

What does the auditory (eustachian) tube connect

Answer 12

the middle ear to the nasopharynx, how people get middle ear infections

Question 13

What is the purpose of the ossicles

Answer 13

transmit vibrations from outer to inner ear

Question 14

Which ossicle is attached to the tympanic membrnae? what muscle innervates it

Answer 14

Malleus, innervated by the tensor tympani

Question 15

Which ossicle is in the middle? Which muscle innervates it

Answer 15

Incus, None

Question 16

Which ossicle leads to the canal to the inner ear? which muscle innervates it

Answer 16

Stapes, Stapedius Muscle

- it’s foot fits into the oval window

Question 17

What are the two muscles that innervate the ossicles? What is their function

Answer 17

Tensor Tympani, Stapedius Muscle

-dampen oscillations of the bones, reducing amplitudes from loud noises.

Question 18

Which part of the ear is the sensory apparatus for hearing and balance

Answer 18

Inner Ear

Question 19

WHat is the inner ear? What fluid is contained within that

Answer 19

Bony labryinth filled with perilymph

Question 20

What are the three parts of the bony labryinth

Answer 20

semicircular canals, vestibule, cochlea

Question 21

Where is the membranous labryinth

Answer 21

within the bony labryinth

Question 22

What is the membranous labryinth

Answer 22

system of sacs and ducts filled with Endolymph

Question 23

What are the two sacs within the membranous labryrinth

Answer 23

Saccule and Utricle

Question 24

What kind of epithelium lines the membranous labryinth

Answer 24

Continuous sheet of simple squamous epithelium

Question 25

What are the specialized regions of epithelium within the inner ear? Where do you find them

Answer 25

In the membranous labryinth we find hair cells. Found at the organ of corti of the cochlear duct, maculae of the Urticle and Sacule sacs and the christae of semicircular ducts

Question 26

What are the hair cells

Answer 26

columnar epithelial cells that either have sterocilia (usually 50-100(or a single kinocilium (usually just one)

Question 27

What causes depolarization in the inner ear

Answer 27

Differential movement of the hair cells relative to the endolymph results in bending of the hairs and thus depolarization

Question 28

What iare the tips of the sterociliar and kinocilia embedded in?

Answer 28

an overlying gelatinous mass which is surrounded by endolymph

Question 29

How many semicircular ducts are there

Answer 29

3 within the semicircular canal

Question 30

What structures determine the position and motion of the head and maintain balance

Answer 30

The vestibular component of the inner ear

Question 31

What is the part of the sacs that has hair cells

Answer 31

The macula , there is one in the utricle, and one in the saccule.

Question 32

How are the semicircular canals oriented?

Answer 32

one horizontal, one frontal and one saggital

Question 33

Which sac are the semicircular canals continous with

Answer 33

The utricle

Question 34

Where are the ampullae in the semicircular ducts

Answer 34

Near the utricle. where there are sensory units, the cristae ampullaris

Question 35

What are type 1 hair cells

Answer 35

contacted by a large nerve fiber ending that surrounds the base of the cell

Question 36

what are type 2 hair cells

Answer 36

Have nerve connectinons from several smaller nerve fibers by small terminal boutons.

Question 37

WHat is the otolithic membrane

Answer 37

The overlying gelatinous mass. It contains calcium carbonate particles called otoliths (the mass of these helps form the force that causes depolarization)

Question 38

Are the cristae ampullaris region or the maculae region sesitive to rotational movement?

Answer 38

cristae ampullaris

Question 39

Are the cristae ampullaris region or the maculae region sesitive to static or linear acceleration of the head

Answer 39

Maculae

Question 40

What shape is the crista ampullaris

Answer 40

cone shaped cupula

Question 41

What are the three layers of the cochlear duct

Answer 41

``` Stria Vascularis (external layer) Vestibular membrane ( superior layer) Basilar membrane ( inferior layer) ```

Question 42

What layer of the cochlear duct attaches to the bony cochlea

Answer 42

Stria Vascularis

Question 43

Where do you find the vestibular membrane of the cochlear duct

Answer 43

It separates the cochlear duct from the scala vestibuli. the superior layer .

Question 44

What does the basilar membrane of the cochlear duct do

Answer 44

It separates cochelar duct from the Dcala tympani and supports the organ of corti

Question 45

Is endolymph or perilymph in the cochlear duct?

Answer 45

Endolymph

Question 46

Is endolymph or perilymph in the scala vestibuli and scala tympani?

Answer 46

perilymph (they are technically part of the bony labryinth)

Question 47

What are the hair cells like at the organ of corti

Answer 47

Some have sterocilia but there is no Kinocilia There is a row of hair cells closer to the central axis of the cochlea called inner hair cells and then 3 rows of cells further out called outer hair cells (U shaped) both cells are surrounded by the tectorial membrane

Question 48

What is the tectorial membrane

Answer 48

gelatinous mass that surrounds the organ of corti cells.

Question 49

Which membrane layer of the cochlear duct has the organ of corti

Answer 49

The basilar membrane

Question 50

What causes otis media

Answer 50

inflammation of the middle ear cavity caused by an upper respiratory tract infection that extends from the nasopharynx. ear tubes if recurring

Question 51

What causes osteosclerosis

Answer 51

Formation of extra bone between stapes and the oval window which results in progressive deafness. an autosomal dominant hereditary defect

Question 52

What causes sensory hair cell toxicity

Answer 52

drug induced irreversible damage of vestibular or cochlear sensory cells, drugs include antibiotics, diuretics, nitrogen mustard, antimalarial drugs

Question 53

Which are the first cells to be damaged with noise induced hearing loss

Answer 53

external hair cells of the organ of corti, a loss of sensory cells is followed by deformation, swelling and disintegration of the hair cells. progressive injury damages supporting cells.