6.15 Embryology of the Ear and Eye

Question 1

the 3 embryonic sources of the eye?

Answer 1

surface ectoderm, neuroectoderm, mesenchyme (mesoderm/neural crest cells)

Question 2

external eye contains?

Answer 2

sclera and cornea

Question 3

middle eye contains?

Answer 3

vascular, choroid, ciliary body and iris

Question 4

inner eye contains?

Answer 4

retina

Question 5

3 compartments of the eye?

Answer 5

anterior, posterior, and vitreous

Question 6

pair of lateral grooves which evaginate from the developing forebrain (eye fields in diencephalon, PAX6) and form the optic vesicles

Answer 6

optic sulci (grooves)

Question 7

induced by mesenchyme adjacent to developing brain, to become cup by lens placode, to inner neural and outer pigment/vascular layer

Answer 7

optic vesicles

Question 8

the renamed optic vesicle once the surface ectoderm has induced invagination

Answer 8

optic cup

Question 9

groove on the ventral surface of the optic stalk, contains hyaloid artery to developing lens

Answer 9

choroid fissure

Question 10

within choroid fissure, supplies the lens with blood during development, degenerates leaving central artery and vein of retina

Answer 10

hyaloid vessels

Question 11

failure of closure of choroidal fissure, PAX 2 mutations, keyhole

Answer 11

coloboma

Question 12

clouding of the lens, galactosemia, rubella during pregnancy

Answer 12

cataracts

Question 13

surface ectoderm by optic vesicle induction, induces optic vesicle to become optic cup

Answer 13

placode

Question 14

separation from inner surface epithelium and formation of lumen

Answer 14

lens vesicle

Question 15

posterior wall cells elongate, primary fibers, secondary fibers fill central core later

Answer 15

lens fibers

Question 16

separates anterior and posterior chambers during development only

Answer 16

pupillary membrane

Question 17

failure to degenerate before birth, surgery or dries up

Answer 17

persisten pupillary membrane

Question 18

outer fibrous layer, continuous with the substantia propria of the cornea and formed from mesenchyme surrounding optic cup

Answer 18

eye development

Question 19

eyelids develop from?

Answer 19

surface ectoderm

Question 20

stromal layer of cornea?

Answer 20

susbtantia propria

Question 21

mesothelium of anterior chamber is derived from?

Answer 21

mesoderm

Question 22

epithelium of cornea and conjunctiva formed from

Answer 22

surface ectoderm

Question 23

develops from walls of optic cup which are continuous with the wall of the developing brain

Answer 23

retina

Question 24

this part of the retina forms from the thinner, outer layer of the optic cup

Answer 24

pigment epithelium

Question 25

the part of the retina forms from the inner, thicker layer of the optic cup under the influence of the lens

Answer 25

neuroepithelium

Question 26

separation of pigment layer from neuroepithelial layer

Answer 26

detached retina

Question 27

nerve fibers grow from the ganglion cells of the retina through the optic stalk to reach the brain, myelination continues after birth

Answer 27

optic nerve

Question 28

pupil muscles grow from neuroectoderm, sphincter and radial muscles

Answer 28

iris

Question 29

absence of the iris

Answer 29

aniridia

Question 30

anterior compartment is the space between the ______ and iris and filled with _______ humor

Answer 30

cornea, aqueous

Question 31

vitreous space is ______ to the lens and zonula attachments

Answer 31

posterior

Question 32

blockage of the canal of Schlemm leading to increased intra orbital pressure

Answer 32

congenital glaucoma

Question 33

forms from the otic vesicle, which develops from the surface ectoderm in the region of the hindbrain

Answer 33

inner ear

Question 34

forms from the 1st branchial pouch (lining of tympanic cavity) and the 1st and 2nd branchial arches (malleus, incus, and stapes)

Answer 34

middle ear

Question 35

develops from the 1st and 2nd branchial arches

Answer 35

external ear

Question 36

caused by genetic factors (Treacher-Collins) or rubella or cytomegalovirus infection

Answer 36

congenital deafness

Question 37

in middle ear, origin from 1st branchial pouch, proximal unexpanded portion forms auditory tube, distal portion forms tympanic cavity

Answer 37

tubotympanic recess

Question 38

part of middle ear from 1st branchial arch

Answer 38

malleus and incus

Question 39

part of middle ear from 2nd branchial arch

Answer 39

stapes

Question 40

in development of the inner ear, thickening of surface ectoderm, developes a lumen and becomes the otic pit

Answer 40

otic placode

Question 41

otic pit becomes otic _____

Answer 41

vesicle

Question 42

______ portion of the inner ear gives rise to utricle, semicircular canals, endolymphatic duct and sac

Answer 42

utricular

Question 43

______ portion of the inner ear gives rise to the saccule and cochlear duct

Answer 43

saccular

Question 44

cavity in the temporal bone divided into 3 sections-vestibule, semicircular canals, and cochlea

Answer 44

bony labyrinth

Question 45

lies within bony labyrinth and is divided into 3 parts-semicircular ducts, saccule, and utricle

Answer 45

membranous labyrinth

Question 46

formation of perilymphatic space from the cartilaginous otic capsule which undergoes vacuolization, and scala tympani and vestibuli by vacuolization of otic capsule

Answer 46

formation of cochlear duct

Question 47

organ of ______ contains hair cells receptors

Answer 47

corti