Face, Nose, Ears, and Eyes Development

Question 1

what forms the hard palate?

Answer 1

ossification of the primary palate and anterior secondary palate

Question 2

which part of ear develops first?

Answer 2

inner

Question 3

where do otic placodes form?

Answer 3

level of caudal hindbrain

Question 4

development of otic placodes

Answer 4

ectoderm invaginates -> pit -> edges pinch off -> otic vesicle (separates from surface ectoderm) -> membraneous labyrinth

Question 5

what does membraneous labyrinth contain?

Answer 5

endolymph and perilymph

Question 6

what does the otic vesicle divide into?

Answer 6

1. utricular region: utricle and semicircular ducts

2. saccular region: saccule and cochlear ducts

Question 7

what forms cochlear duct?

Answer 7

is extension of saccular region and forms membraneous cochlea

Question 8

perilymphatic space

Answer 8

formed by vacuoles around duct

Question 9

components of perilymphatic space

Answer 9

1. scala vestibuli

2. scala tympani

Question 10

spiral organ of corti

Answer 10

formed by cells in wall of membraneous cochlea

Question 11

what forms spiral ganglion in cochlear duct?

Answer 11

CN VII cell bodies

Question 12

what does the pharyngotympanic tube develop from?

Answer 12

tubotympanic recess in middle ear

Question 13

embryological origins of middle ear structures

Answer 13

melleus: arch I
incus: arch I
stapes: arch II
external acoustic meatus: groove I

Question 14

what does the auricle of outer ear develop from? and where?

Answer 14

auricular hillocks (mesenchymal proliferations), at level of 1st groove

Question 15

location of optic groove, and progression of development

Answer 15

procencephalon

optic groove -> optic vesicles -> optic cups -> optic stalks

Question 16

what covers the optic cup?

Answer 16

lens placode (->lens pit -> lens vesicle)

Question 17

what is lens made of?

Answer 17

invagination of surface ectoderm

Question 18

layers of optic cup

Answer 18

inner: neural retina
outer: retinal pigmented epithelium (location of rods and cones)

*separated by intraretinal space (not present in adults)

Question 19

origin of iris

Answer 19

neural crest (choroid and retina contribute)

Question 20

what cells are responsible for producing aqueous humor?

Answer 20

ciliary body

Question 21

facial primordia

Answer 21

1 frontonasal prominence
2 maxillary proms
2 mandib proms

Question 22

when does facial development occur and what movement happens during it?

Answer 22

during fetal period (month 3)

cranium expands, eyes move ant and med, ears move sup, nose is more prominent

Question 23

nose development progression

Answer 23

nasal placodes -> nasal pits (epithelium, deepen and expand dorsally) -> nasal sacs -> R and L nasal cavitiea

Question 24

what separates nasal and oral cavities?

Answer 24

oronasal membrane-ruptures at 6 weeks, communivation occurs via primordial choanae

Question 25

what does the development of secondary palate form?

Answer 25

definitive choanae (space) separating nasal cavity from nasopharynx

Question 26

what does olfactory epi originate from?

Answer 26

neuroectoderm

Question 27

intermaxillary sinus

Answer 27

• fusion of medial nasal prominences,
• philtrum, premax part of max
  (incisors) , primary palate

Question 28

formation of secondary palate

Answer 28

• hard and soft palate, and uvula

- lateral palatine processes (mesenchyme) extend medially from max proms, swing up and fuse with eachother