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56 Cards in this Set
- Front
- Back
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Optic grooves are extensions of the ___ ___ and so they are lined by ___ ___.
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extensions of the NEURAL TUBE
lined by NEURAL ECTODERM |
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During eye development, optic grooves extend outward into larger structures called ___ ___.
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optic vesicles
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What stimulates the formation of the lens placode?
What does this stimulation of the lens placode do in return? |
optic vesicles coming into close contact with surface ectoderm
in return, the lens placode will stimulate the optic vesicle to continue forming and to form an optic cup |
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What is the choroid fissure? What does it do?
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gap that is left along the ventral surface of the optic cup as it invaginates
allows passage for hyaloid vessels from the brain into the lens |
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Hyloid vessels will _____ and only be present in the adult where?
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will DEGENERATE and only be present in the adult in the optic stalk & retina
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What is the optic stalk?
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connection of the optic cup to the forebrain
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The optic cup has 2 layers. An inner and an outer. Which one is thick and which one is thin?
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inner - thick (10 cell layers)
outer - thin (1 cell layer) |
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The inner layer of the optic cup develops into what 2 things?
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1 - pars optica retina
-from the posterior 4/5ths -"neural retina" for vision 2- pars ceca retina -from its anterior 1/5 -non-visual tissues (ciliary body & iris) |
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The outer layer of the optic cup becomes what?
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retinal pigmented epithelium
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The basis for retinal displacement lies in the fact that....
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the space between the inner and outer layer of the optic cup persists (gets smaller through eye development but is still a space)
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True or False: Light has to travel all the way through the retina to get to the photoreceptors and then travel all the way back.
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True.
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The ciliary body and iris develop from what?
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pars ceca retina which is the anterior 1/5th of the inner layer of the optic cup
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The ciliary body produces ___ ___ which is important for normal eye maintenance.
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aqueous humor
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Ciliary muscles are formed from?
Ligaments of these muscles control what? |
neural crest
ligaments of these control lens shape for vision adjustment |
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The pigmented part of the eye is called the ___. The pigmentation is due more so to melanocytes in the ___ rather than the ____.
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iris
more so due to melanocytes in the STROMA rather than the epithelium |
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Muscles of the iris are formed from what? Function?
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neural crest
function to open/close the pupil |
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The lens placode will form a ___ that will then detach from the surface to become a ____ ____ surrounded by the optic cup.
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will form a PIT
detaches and becomes a LENS VESICLE |
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Posterior cells of the lens vesicle will ______ to become lens ____.
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will ELONGATE to become lens FIBERS
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The optic cup comes from ____ ___ and the lens placode comes from ___ ___.
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optic cup from NEURAL ECTODERM and lens placode from SURFACE ECTODERM
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The choroid, sclera, vitreous body, and part of the cornea all form from specializations of what?
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neural crest
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What stimulates the formation of the choroid from neural crest? What is the choroid?
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the optic cup stimulates
the choroid is a vascular bed (layer of blood vessels) adjacted to the retinal pigmented epithelium |
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What is the white of the eye called? Formed from? function?
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sclera
formed from neural crest function is supportive |
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What is the vitreous body?
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a gel like part of the eye formed from neural crest
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How are the eyelids formed?
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surface ectoderm folds in on itself
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The cornea is formed partially from ___ ___ and partially from ___ ___.
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neural crest and surface ectoderm
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Where is the anterior chamber of the eye?
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between the surface ectoderm of the cornea and the lens
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An intermediate membrane that is between the cornea and the lens is called the ___ membrane. It normally degrades but occasionally does not.
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PUPILLARY membrane.
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The central arteries and veins of the eye in the adult were once the ____ vessels.
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HYALOID vessels
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The optic stalk will become the ___ ___ in the 6th to 9th week of development. How?
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optic nerve
retina differentiates --> ganglion cells extend long axons --> axons fill up the optic stalk --> optic nerve |
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The master switch for eye development is called ____ __.
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Pax 6
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A mutation in pax 2 can lead to _____ which is when the ___ ___ does not resolve.
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coloboma
choroid fissure does not resolve |
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What are 2 eye defects associated with mutations in pax 6?
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microphthalmia (small eye)
anophthalmia (no eye) |
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A persistent iridopupillary membrane is a .....?
Causes? |
remnant of neural crest in the anterior chamber
Causes a web of tissue interfering with vision |
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Where does the inner ear develop?
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within the petrous portion of the temporal bone of the skull
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Fill in the blanks.
otic placode --> otic ___ --> otic vesicle --> ____ ____ ____ |
otic placode --> otic pit --> otic vesicle --> 3 part sac
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The utricular portion of the otic vesicle will become what?
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semicircular canals of the inner ear
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The semicircular canals of the inner ear function to do what?
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sense movement for balance/rotation
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The saccular portion of the otic vesicle will become what?
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the cochlear duct
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Where is the organ for hearing contained? What is it called?
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contained in the cochlear duct
called the Organ of Corti |
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What is the cochlear duct?
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extension of the saccular portion of the otic vesicle
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Inner ridge cells of the cochlear duct become what?
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tectoral membrane
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Outer ridge cells of the cochlear duct differentiate into what?
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hair cells
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Hair cells of the cochlear duct are innervated by what?
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vestibulocochlear (CN VIII)
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What are the 3 cavities that form around the cochlear duct?
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scala tympani - underneath duct
scala vestibule - above duct scala media = lumen of duct |
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Dilated areas at the ends of the semicircular canals are called ___ ____.
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crus ampullare
(the ampulla) (crista ampullaris) |
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Hair cells of the semicircular canals are embedded in the ____, a gelatinous mass. (Each canal has 1)
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cupula
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The middle ear consists of the ____, ____, and ____. The (first 2) form from branchial arch __ and the (last one) forms from branchial arch __.
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malleus, incus, and stapes
malleus & incus from branchial arch 1 stapes from branchial arch 2 |
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The cavity of the middle ear (auditory tube) forms from what?
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extension of branchial pouch 1
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The external acoustic meatus of the middle ear forms from what?
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branchial groove 1
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The tympanic membrane of the ear forms from what?
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branchial membrane 1
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When sound hits the tympanic membrane (ear drum) it travels from where to where? about 8 steps
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malleus --> incus --> stapes --> oval window of inner ear --> vibrations to scala tympani fluid --> movemnt in basilar membrane of the Organ of Corti --> hair cells move --> sound perception
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What are the 2 muscles of the middle ear? Where does each form from?
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tensor tympani from branchial arch 1
stapedius from branchial arch 2 |
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The tensor tympani muscle of the middle ear is innervated by? What is its function?
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innervation: V3 of trigeminal
function: protect ear from too strong of vibrations (loud noises) |
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The stapedius muscle of the middle ear is innervated by? Function?
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innervation: facial nerve
function: prevents stapes from hitting the round window too hard |
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The auricle develops in the area of the first and second branchial arches as _ (#) ____ ____.
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6 auricular hillocks
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Auricular hillocks (which develop into the auricle) are covered in ____ ____ but are internally composed of ____ ____.
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covered in SURFACE ECTODERM
internally composed of NEURAL CREST |
