Embryology of the Ear Flashcards Preview

Embryology > Embryology of the Ear > Flashcards

Flashcards in Embryology of the Ear Deck (39):
1

cristae ampullaris

in the ampulla of each semicircular canal

2

macula

one in the utricle and one in the saccule

3

cochlear

numerous along the cochlear duct

4

what is the thickening of ectoderm called during the fourth week of development

ecotderm

5

the otic placode forms __________ and then _______

otic placode and vesicle

6

_________gives rise to the membranous labyrinth

otic vesicle

7

the otic vesicle forms what two structures

utricle and saccule

8

the utricle forms

endolymphatic duct, utricle and semicircular canals

9

the saccule forms

the saccule and cochlear duct

10

the _____________ is related to the cochlear duct and is involved in hearing

spiral ganglion

11

the ____________is involved in detection of movement of the head

vestibular ganglion

12

the ganglia form from

neural crest cells

13

the otic capsule helps also form what skull bone

petrous part of the temporal bone

14

what is the space called within the otic capsule

perilymphatic space

15

what is the fluid within the perilymphatic space called

perilymph

16

_________can cause malformation of the cochlea and deafness

rubella infection

17

what is the significance of the perilymphatic space and the cochlear duct

it is related to it twice (once above and once below)

18

What are the two space of the perilymphatic space called

scala tympani and scala vestbuli

19

what helps form the tympanic membrane

the first pharyngeal groove

20

what is the pouch lined with

endoderm

21

what is the groove lined with

ectoderm and mesenchyme

22

what germ layers is the tynmpanic membrane derived from

ecto, endo, meso (all three!)

23

the 1st pharyngeal pouch helps form

the middle ear which is continuous with the mastoid antrum and nasopharynx ia pharyngotympanic tube (auditory tube)

24

what are the three middle ear ossicles

malleus, incus, and stapes

25

malleus and incus are derived from

1st pharyngeal arch

26

stapes is derived from

cartilage of the second arch

27

tensor tympani m is attached to ________and is derived from ________arch

malleus; mesenchyme of first arch

28

the tensor tympani is innervated by

CN V

29

stapedius is innervated by

facial nerve

30

external ear develps at the crossroads of

1st and 2nd pharyngeal arches

31

what is anotonia

absence of an ear

32

what is microtia

small ear

33

auricular appendages

persistence of auricular hillocks

34

what dis microtia result from

absence of auricular hillocks and is characterized by the absence of the auricle; this defect is associatied with other defects

35

___________-are small depressions located anterior to the auricle

preauricular sinuses

36

preauricular sinuses are the result from

abnormal closure of the first pharyngeal groove

37

what happens when the plug of cells in front of the tynpanic membrane fail to regress

atresia of external auditory meatus occurs

38

__________is when epidermoid tissue is within the tympanic membrane

congenital cholesteatome

39

congenital fixation of the stapes

Complete absence of the annular ligament of the stapes without evidence of otosclerotic bone growth may be congenital stapes fixation.