Vision Flashcards

1
Q

Eyelids

A

separated by the palpebral fissure

meet at medial and lateral angles (canthi)

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2
Q

lacrimal caruncle

A

reddish elevation at the medial canthus

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3
Q

tarsal plates

A

connective tissue within the eyelids

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4
Q

Levator palpebrae superopris muscle

A

moves upper eyelid

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5
Q

conjenctiva

A

transparent mucous membrane

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6
Q

larimal apparatus

A
keeps the surface of the eye moist.
lacrimal gland
larimal punctum
larimal canaliculus
lacrimal sac- fluid empties into nasal cavity
nasolacrimal duct
inferior meatus
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7
Q

Eye Muscles

A

lateral rectus- lateral-abducens
medial rectus-medial-oculomoter
superior rectus- elevates, medial turn- oculomotor
inferior rectus- depresses, medial turn- oculomotor
inferior oblique- elevates, lateral turn- oculomotor
superior oblique- depresses, lateral turn- trochlear

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8
Q

Posterior Segement of Eye

A
divided by ciliary zone and lens
filled with vitreous humor- clear jelly like
transmits light 
supports posterior surface of the lens
helps maintain intraocular pressure
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9
Q

Anterior Segment of Eye

A

contains both anterior and posterior chambers
anterior chamber- between the cornea and iris
posterior chamber- between iris and lens
both filled with aqueous humor

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10
Q

Glaucoma

A

increased pressure in anterior segement due to slow draining aqueous humor. causes compression of retina and optic nerve

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11
Q

Lens

A

thick transparent, biconvex disc
held in place by ciliary zonule
elongated lens fibers form bulk of lens
lens gets bigger throughout life

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12
Q

Light bending structures

A

lens, cornea, humors

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13
Q

accomodation

A

curvature of the lens is adjustable which allow focusing on nearby objects

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14
Q

Wall of eye- fiborous layer

A

most external
dense connective tissue
sclera and cornea

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15
Q

sclera

A

posterior 5/6 of the tunic
white region
provides shape and anchor for the eye muscles

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16
Q

cornea

A
anterior 1/6 of eye
connected to sclera by the limbus
has epithelium and endothelium
avascular but gets O2 from environment
many sensory nerves, much are pain receptors
17
Q

scleral venous sinus

A

allows aqueous humor to drain

18
Q

Wall of eye- vascular layer

A

middle layer
choroid
cilliary body
iris

19
Q

choroid

A

vascular
dark pigmented
posterior 5/6 of vascular tunic
brown
prevents scattering of light rays within the eye
choroid corresponds to the arachnoid and pia maters

20
Q

Ciliary Body

A

thickened ring of tissue which encircles the lens
mainly smooth muscle that focuses lens
made of :
ciliary processes and ciliar zonule (suspensory ligament- halo of fine fibers around lens)

21
Q

Iris

A

colored part

smooth muscle, attached to ciliary body

22
Q

pupil

A

round central opening
sphincter pupillae muscle (circular)
dilator pupillae muscle (radial)

23
Q

Wall of Eye- inner layer

A

retina

optic nerve

24
Q

Retina

A
deepest. 
2 layers:
pigemented- outer
neural- inner, has nervous tissue
photoreceptor cells, bipolar cells and ganglia (acramine and horizontal sometimes)
25
Q

macula lutea

A

contains mostly cones

26
Q

fovea centralis

A

only cones. visual acuity

27
Q

optic disc

A

blind spot

28
Q

rods & cones

A
rods- sensitive to light
cones- color
both have 2 segments
outer- receptor region 
inner- generate nerve impulse
29
Q

Visual pathway to cerebral cortex

A

optic nerve–> optic chiasm–> optic tract–> lateral geniculate nucleus of thalamus–> optic radiation–> primary visual cortex

30
Q

visual pathways to other parts of the brain

A

midbrain:
superior conlliculi: controls extrinsic eye muscles
pretectal nuclei: mediate pupillary eye reflexes

suprachiasmatic nucleus

31
Q

Blood supply to retina

A

outer 1/3 gets it from caps in choroid

inner part gets it from central artery

32
Q

cataracts

A

lens becomes opaque. people over 50

33
Q

macular degeneration

A

buildup of deposits in the retina causing loss of vision in the macula which is the center of the visual field

34
Q

trachoma

A

contagious infection from chlamydia of conjunctiva. causes the eyelids to become distorted and inverted causing eyelashes to scrape against cornea. leads to scarring and blindness.