Ear

Question 1

What is the function of the external ear?

Answer 1

collect sound waves

convert soundwaves to mechanical vibrations

Question 2

What is the function of the middle ear

Answer 2

Amplifies mechanical vibrations

Question 3

What is the function of the internal ear

Answer 3

converts fluid vibrations to nerve impulses

detect (sound, orientation, acceleration)

Question 4

What are the three main structures of the external ear?

Answer 4

Auricle
External Acoustic meatus
Tympanic memrane

Question 5

What is the function of the Auricle

What does the Auricle have? skin

Answer 5

catch sound waves

-thin skin (hair, sweat, sebasous glands)

Question 6

What glands do the External acoustic meatus have? and what is it’s function

Answer 6

Ceruminous glands (modified sweat glands)
Secrete waxy cerumen

Question 7

What is the function of the tympanic membrane?

What is the tympanic membrane made of?

Answer 7

Convert soundwaves-> mechanical vibrations

• lined by external skin (ectoderm)
• Simple cuboidal epithelium (endoderm)

Question 8

What are the three oossicles of the middle ear?

Answer 8

malleus (hammer)
-attached to tympanic membrane
Incus (anvil)
Stapes (stirrup)
-sits in oval window

Question 9

What is the attenuation reflex to loud sounds?

Answer 9

Tensor tympani and stapedius dampen vibration of oossicles

Question 10

What is the middle ear lined by?

Any glands?

Answer 10

pseudostratified columnar epithelium

mucous glands in auditory tube

Question 11

What two labrynths makeup the internal ear?

Answer 11

Bone labrynth

Membranous labrynth

Question 12

Where is the bone labrynth?

What is it filled with?

Answer 12

space within temporal bone

perilymph

Question 13

Where is the membranous labrynth?

What is it filled with?

Answer 13

sacs suspended within bone labrynth

endolymph

Question 14

What does the membranous labrynth contain?

Answer 14

vestibular labrynth, cochlear labrynth

Question 15

What does the bone labrynth contain?

Answer 15

cochlea, vestibule, semicircular canals

Question 16

How many semicircular canals are there and at what angle to they sit to each other?

Answer 16

3 (anterior, posterior, lateral)

90 degrees

Question 17

Where is the vestibule and what does it contain?

Answer 17

between cochelea and semicircular canals

oval and round windows

Question 18

What does the chochlea coil around?

Answer 18

2 1/2 coils around Modiolus

Question 19

what is the Modiolus?

Answer 19

central bony core of internal ear

Question 20

What does the vestbular labrynth contain

Answer 20

saccule and utricle (both have macula)
Semicircular ducts (crista ampulallaris)

Question 21

What does the cochlear labrynth contain

Answer 21

Cochlear duct (spiral organ of corti)

Question 22

How many types of vestibular sensory hair cell organs are there? and what do they have

Answer 22

2 Types
both have sterocilla
type 1 has 1 kinocilium which gives direction

Question 23

What is the macula responsible for?

Where is it?

Answer 23

Linear acceleration

within utricle and saccule of vestibule

Question 24

What is the function of the saccule

what is the function of the utricle

Answer 24

saccule=verticle acceleration

utricle= horizontal acceleration

Question 25

Hair cells of the vestibule are embeded in what? and what sides of cells?

Answer 25

Otolihic membrane | Apical surface of hair cells

Question 26

What is the otolithic membrane and what does it have?

Answer 26

Gelatinous sheet with crystals (otoconia or otoliths) lining the surface

Question 27

What are the sense organs of the semicircular ducts?

Answer 27

crista terminale

Question 28

What is the function of crista terminale?

Answer 28

detect angular/rotational acceleration within ampullae of semicircular ducts

Question 29

Where are hair cells of the semicircular ducts?

Answer 29

on the epithelial ridge embedded in cupula (gelatinous cap over sensory epithelium)

Question 30

What is vertigo caused by?

Answer 30

otoconia dislodged from otholitic membrane | - fall into ampulla-> stimulates cirsta ampullaris

Question 31

What are the 3 changers of the cochlear labrynth and what are they divided by?

Answer 31

Sacala vestibule, sacala tympani, scala media | Cochlear duct

Question 32

What seperates the sacal vestibule duct from the cochlear duct and what does the sacal vestibule contain?

Answer 32

vestibular membrane | perilymph

Question 33

What does the scala tympani contain and how does it communicate with the tympanic cavity?

Answer 33

perilymph | round window

Question 34

what is the function of the Basal membrane? | What does that attach to and what does it support?

Answer 34

seperates the scala tympani and the scala media - attaches to osseous spiral lamina - supports spiral organ of corti

Question 35

What section of the cochlear labrynth contains endolymph?

Answer 35

scala media

Question 36

What is the function of the spiral organ of corti? What does it contain? Where is it?

Answer 36

hearing hair cells scala media

Question 37

Where can the stria vascualris, spiral ligament, tectoral membrane be found?

Answer 37

Scala media

Question 38

What does the strai vascularis of the scarla media provide?

Answer 38

endolymph

Question 39

What does the spiral ligament of the scarla media do?

Answer 39

- attaches cochlear duct to the outer wall of cochlea | - supports basilar membrane

Question 40

What does the tectoral membrane of the scarla media do? and what does it contain?

Answer 40

Overlies spiral organ of corti | has embedded hair cells

Question 41

Where can the spiral limbus be found and what does it do?

Answer 41

the tectoral membrane of the scarla media | - secretes and anchors tectoral membrane to wall of medial cochlea

Question 42

What are the sensory cells of the spiral organ of corti? | and what do they have?

Answer 42

hair cells (inner and outer) sterocillia embedded within tectoral membrane

Question 43

What are the supporting cells of the spiral organ of corti?

Answer 43

``` Phalaneal cells -(Inner and outer) -supports hair cells Pillar cells -(inner and outer) -forms tunnel of corti ```

Question 44

How is pitch detected? what end is high/low and why?

Answer 44

width of basal membrane base=high pitch= thin end=low pitch=thick

Question 45

What are the two types of nerves of the ear?

Answer 45

Vestibulocochlear N CN8 | Bipolar neurons

Question 46

What are the two types of biolar neurons of the ear? What do they each innervate? and where are their ganglia?

Answer 46

Vestibular N. = balance - ganglia in internal acoustic meatus Cochlear N. = hearing - spiral ganglia located in modiolus