eye Flashcards
what are fibrous coat derived from
mesodermally derived
what are the fibrous coats of the eyeball
Sclera and choroid
what are derivatives of ectoderm
Lens
Retina
Cornea
Pigmented layers
what are the three coats or tunics the eyeball is composed of
Fibrous tunic
vascular tunic
nervous tunic (retina)
what is the white part of the eye
Sclera
what part of the eye is thick, dense, firm, and opaque and maintains the shape of the eyeball if pressure inside the eyes increases
Sclera
many tiny openings in the sclera allow what to pass through
blood vessels
Neurons (nerve fasicles)
where do extraocular muscles attach
to the sclera
what part of the sclera is lined with conjunctiva and transitions to the cornea
Anteriorly
at what point does the Sclera transition to the Cornea
at the limbus
the posterior part of the sclera is continuous with what fibrous sheath
the fibrous sheath that covers CN II
what is the primary refractory part of the eyeball
the Cornea
what are the five layers of the Cornea
Corneal epithelium anterior limiting lamina substantia propria posterior limiting lamina endothelium
describe the color of the cornea
clear and transparent
what layer of the cornea is continuous with the conjunctiva
Corneal epithelium
what is the thickest, largest part of the cornea
Substantia propria
what layer of the cornea covers the inside surgace of the cornea and lines the iridocorneal layer
endothelium
what are the different vascular tunics
Chorioid
Ciliary body
Iris
which layer of the vascular tunic is thin with a rich blood supply and has a lot of sympathetic influence
Choroid
the blood vessels of the choroid are heavily supplied by what fibers
Autonomic and vasomotor
at what point is the choroid firmly attatched to the Sclera
where the optic nerve penetrates it
what holds the loosely attached Choroid to the Sclera
eyeball pressure
why is the choroid darkly pigmented
limit passage of light both through the sclera to the retina and through the retina to the sclera
what is the ciliary body continuous with
the Choroid to the post. and the Iris to the Ant.
what suspends/anchors the lens
the ciliary body
what does the ciliary body produce
Aqueous fluid found in the anterior segment of the eye
maybe some GAGs of the vitreous body
what is the dividing point of the eye for the ant. segment and post. segment
the lens
what is the function of ciliary muscles
contraction of the ciliary muscles allows the lens to become more convex
a more convex lens helps what type of vision
near/closer vision
what is the colored part of the eye
Iris
what is the range of color of the iris
light blue to dark brown
what divides the anterior segment into and ant. and post. chamber
the iris
what is the ant. chamber between
the cornea and iris
what is post. chamber between
the iris and lens
what two muscles control the size of the pupil
sphincter pupillae
dilator pupillae
where are the sphincter pupillae and dilator pupillae located
the iris
what is and outgrowth of diencephalon and considered to be a specialized portion of the brain
the nervous tunic/retina
the Retina is in contact with the _______ externally and the _________ internally
Choroid, vitreous body
what layer of the retina is the problem when there is a detached retina
the pigmented layer also called the cementing layer
what cells are associated with the vision pathway
photoreceptors –> bipolar cells –>multipolar cells –> axons form the optic radiation –> synapse in Broadman area 17
what can be seen with a funduscopic exam
the optic disc
macula lutea
fovea centralis
what is the point at which the optic nerve attaches to the eyeball
the optic disc
what part of the eye has no photoreceptors
the optic disc
what is the middle of the maculae lutea refered to as
the fovea centralis
what are has the clearest vision and the only photoreceptors are cones
the macula lutea
what are the refractory components of the eye
Cornea
Aqueous humor
lens
vitreous body
what fluid is secreted into the posterior chamber
Aqueous humor
where does aqueous humor pass through to get into the ant. chamber? and where does it leave the eyeball?
through the pupil
out the scleral venous sinus
what results from increased pressure within the ant. chamber of the eyeball that can result in blindness
Glaucoma
what part of the eye is transparent, biconvex, and avascular
the lens
what is it called when the lens gets harder with age, resulting in more difficult near vision
Presbyopia
what is it called when the lens becomes less and less transparent
cateracts
what fills the posterior segment, and is Gelatinous and transparent
Vitreous body
in relationship to the eye where are lacrimal glands located and what do they secrete
superolaterally to the eyeball, secrete tears
what carried tears to the eye from the lacrimal glands
excretory ducts
where are lacrimal ducts found and what do they do
they are in each eylid below and medial to the eyeball they drain tears
where are tears drained to from the lacrimal ducts
lacrimal sacs
lacrimal sacs are found in a grove between which two structures
the lacrimal bone and maxilla
what is the most superior part of the nasolacrimal duct
the lacrimal sac
what drains tears from the lacrimal sac into the inferior nasal meatus
the nasolacrimal ducts
what is a modified sebaceous gland that secretes and oily substance that covers tear upon blinking.
Tarsal glands
what is the oily coat secreted by tarsal glands function
reduce the evaporation of tears
all arteries to the eyball are branches of what artery
the Opthalmic Artery
each eyball has one long posterior ciliary artery on each side (medial and lateral) that runs between what structures
the Sclera and Choroid
each eyeball has six to twelve of these arteries that ender the eyeball on the posterior surface forming a ring around the optic nerve
short ciliary arteries
each eyeball has six to eight of these arteries that arch of or under the eyeball
anterior ciliary arteries
what artery of the eyeball travels via the optic nerve to the retina then spreads out into an extensive network
Central retinal artery
what is the only artery that supplies the retina
central retinal artery
what are the veins of the eye
ant. ciliary vein
long post. ciliary vein
central retinal vein
what are the nerves of the eyeball that branch of the nasociliary nerve (CN V1)
long ciliary nerves
short ciliary nerves
what are the long ciliary nerves sensory for
the ciliary body, iris and cornea
what are short ciliary nerves sensory for
the eyeball
