Head and Neck Lecture Notecards

Question 1

What is the correct formation of the eye in development

Answer 1

optic groove –> optic diverticula –> optic stalk –> optic vesicle –> optic cup –> lens placode

Question 2

what is the retinal fissure?

Answer 2

invagination process of the optic vesicle into the ventral part of the optic stalk

Question 3

what does the retinal fissure transmit?

Answer 3

mesenchyme and hyaloid vessels

Question 4

what results as a failure to close the retinal fissure?

Answer 4

coloboma of the iris “keyhole pupil”

Question 5

what are the three layers of the retina?

Answer 5

pigment layer
neural layer
intra-retinal space

retina develops from the layers of the optic cup

Question 6

which space provides easy plane of cleavage of detatchment of retina?

Answer 6

intra retinal space

Question 7

where does detachment occur?

Answer 7

between neural and pigment layers

Question 8

what cells give rise to pupillary muscles

Answer 8

neuroectodermal cells

Question 9

where does the ciliary body develop between?

Answer 9

developing retina and iris

Question 10

what gives rise to ciliaris muscle?

Answer 10

adjoining mesenchyme

Question 11

what does the optic nerve develop from?

Answer 11

optic stalk

Question 12

what does the lens develop from?

Answer 12

lens vesicle (surface ectoderm)

Question 13

after 6 mo. the lens becomes…?

Answer 13

avascular - hyaloid vessels degenerate

Question 14

what is congenital aniridia?

Answer 14

absence of iris - rare anomoly due to an arrest of development at the rim of the optic cup

Question 15

what is congenital aphakia?

Answer 15

absence of the lens - rare anomoly due to failure of lens placode to form

Question 16

what is congenital cataract?

Answer 16

lens appears white and opaque at birth

due to maternal rubella infections

Question 17

what is persistent hyaloid artery?

Answer 17

remnants of hyaloid canal or artery can be seen as floats which can interefere with vision

Question 18

what is microphthalmia?

Answer 18

small eye due to arrested development

due to rubella infection

Question 19

what two anomolies of the are due to maternal rubuella?

Answer 19

microphthalmia and congenital cataracts

Question 20

what is anophthalmia?

Answer 20

complete absence of the eye
eyelids are present
may be assocated with other craniocerebral defects

Question 21

what is crytophthalmos?

Answer 21

hidden eye occurs due to failure of the development of palpebral fissure
the eye ball is small or defective and lies beneath the skin

Question 22

what does vitrous humor come from?

Answer 22

mesenchyme

Question 23

how do choroid and sclera develop?

Answer 23

mesoderm surrounding optic cup

Question 24

whhat layer does corneal epithelium come from?

Answer 24

ectoderm

Question 25

what layer does fibrous stroma come from ?

Answer 25

mesodermal capsule covering the optic cup

Question 26

what layer does the corneal endothelium come from?

Answer 26

neural crest cells

Question 27

what does the pinna of the ear develop from?

Answer 27

6 auricular hillocks - 3 from 1st pharyngeal arch and 3 from 2nd pharyngeal arch

Question 28

what does the meatal plus eventually form?

Answer 28

external auditory meatus

Question 29

the tympanic membrane is derived from which germ layer?

Answer 29

all 3!