Lecture Outline #19: Special Senses: Eye Flashcards

1
Q

the eye

A

extension of the brain, diencephalon is pushed out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

fibrous tunic

A

sclera & cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

sclera

A

dense CT - white of the eye
attachment site for muscles of the eye
elastic/mechanical support for globe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

cornea

A

modified sclera - 1/6th of globe
avascular, translucent bulge @ anterior surface, gets nutrients through humor and air in the environment
bends light to focus on retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

optical axis

A

straight line from center of pupil to back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

vascular tunic

A

choroid, ciliary body (m. & sus ligs), iris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

choroid

A

inner posterior surface of globe
vascular - nourish the retina
black pigmentation absorbs stray light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

ciliary body

A

CN III
ciliary m. - smooth m. of radial and circular fibers, contraction reduces tension of sus ligs, doesn’t pull on sus ligs
suspensory lig - zonular fibers, an/post to lens, attach through ciliary m. to sclera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

ora serrata

A

junction of choroid and cil body
where choroid and retina merge @ non-photic aspect of retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

iris

A

smooth m - circular & radial m.s (antagonists
- pupillary constrictor m. (sphincter) parasym stimulation - pupil contraction
- pupillary dilator m.s (radial) sym stimulation - pupil dilation
regulates amount of light that passes to retina
separates ant cavity into ant/post chambers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

anterior cavity

A

filled with aqueous humor (~CSF) - helps control intra-ocular pressure, produced by the ciliary process, returned to blood supply via Canal of Schlemm (venous drainage to dural sinuses) by going through pupil.
- anterior chamber - ant to iris
- posterior chamber - post to iris, ant to lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

posterior cavity

A

filled with vitreous humor - gel-like fluid that assist sclera in maintaining shape of globe
posterior to lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

sus lig

A

barrier btw. ant/pot cavities
composed of two fused membranes
lens is sandwiched/suspended btw. layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

glaucoma

A

circulation of aqueous humor is blocked so it stays btw iris & cornea, increased pressure - damage to nerve, compresses BVs and pushes on retina
cloudy/gray-green eye, assoc. with high blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

neural tunic - matter

A

retina
gray matter - deep, rods and cones
white matter - superficial, vasculature/ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

retina - posterior pigmented layer

A

dark pigmentation absorbs stray light
supports anterior neural layer
integration center

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

retina - anterior neural layer

A

contain 9 layers of cells
around 130 mill photoreceptors
houses neurons, neuroglia, ganglia, BVs, rods, cones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

photoreceptors

A

not chemoreceptors
rods - gray-scale, dim light, around 125 mill per
cones - color vision, around 6 mill per, take lots of energy to activate, absence of one type = color blindness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

light flow

A

retina - optic n. - optic chiasm - optic tract - lateral geniculate nuclei of the thalamus, superior colliculi - primary vision cortex of the occipital lobe

20
Q

macula lutea & fovea centralis

A

center of visual axis
fovea is the focal pt, has the highest # of cones for greatest resolution and is the pit inside the macula

21
Q

blind spot

A

optic disc, 10 degrees off and medial to fovea
pt where optic n. exits globe and BVs enter/exit, no photoreceptors

22
Q

red and cat eye

A

red - vasculature in retina
cat - additional layer = tapetum lucidum - reflected disc that activates photoreceptors

23
Q

globe of the eye & retina

A

formed as lateral diverticula of the di, each diverticulum collapses to form eye-cup
each retina retains early neural tube arrangement and appears to be installed backwards

24
Q

clinical implications/mechanical limitations of eye

A
  1. light receptors point wrong way
  2. receptors buried behind a layer
  3. blind spot
    = 70% of image is lost
25
Q

pineal gland

A

acts as third eye
same make-up as retina
out pocketing of the di (diverticulum)

26
Q

photic sneeze reflex

A

when look at sun = sneeze
autosomal dominant trait, 20% Caucasian and female, protective reflex (450mph)
II retina - III iris - III - V- bs

27
Q

lens

A

thick biconcave disc of specialized fibers
avascular - get aqueous/vitreous humor/nutrients from ant/post cavities.
suspended from sclera by sus ligs

28
Q

accommodation

A

ability to focus, lens fine tunes image on fovea within center of macula lutea
close objects - c m. contracts, ligs sag = lens bulges
far objects - c m. relaxes, ligs tighten = lens thins

29
Q

presbyopia, myopia, hyperopia

A

pres - lens proteins become stiff w/ old age, can’t focus on near object, refractive properties change
myo - nearsightedness
hyp - farsightedness

30
Q

cataracts

A

abnormal lens
combo of structural/bio-mechanical problems
lens becomes cloudy so less light passes to retina, focus becomes patchy

31
Q

astigmatism

A

refractive errors/shaping of the cornea
contacts/glasses bens light correctly

32
Q

levator palpebrae superioris

A

lifts upper eyelid CNIII

33
Q

orbibularis oris

A

sphinctor muscle, closes eyelid, CN VII
can help focus - squinting: pressure on anterior aspect of eye = lens gets more fat and image is a bit more focused

34
Q

introrbital fat

A

posterior portion of eye
if malnourished - fat goes away and eyes are sunken

35
Q

lateral rectus

A

VI, lateral/abduction of the eye

36
Q

medial rectus

A

III, medial/adduction of the eye

37
Q

superior rectus

A

III, elevate the eye

38
Q

inferior rectus

A

III, depress the eye

39
Q

superior oblique

A

IV, depress/abduct the eye, superolateral aspect, goes through a pully called the trochlea

40
Q

inferior oblique

A

III, elevate/abduct the eye

41
Q

palpebrae

A

superioris & inferioris (eyelids)
tarsal plate found within it
lined with epithelium & hair
innervated by V1&2

42
Q

canthi

A

medial (w/caruncle) & lateral
caruncle is the remnant of 3rd eyelid

43
Q

conjunctiva

A

produces own tears & mucous
single layer of skin that covers anterior surface of eye and fused with corneal epithelium
innervated by V1
tear secretion: parasym motor - VII
two types
1. palpebral - inside palpebrae
2. bulbar - on sclera
conjunctivitis - pink eye
conjunctival hemorrhage - ruptured BVs
sclera conjunctivitis - hangover

44
Q

lac gland

A

superolateral corner of orbit
secretes tears that bathe conjunctiva & corner

45
Q

lac apparatus

A

tears are squeezed into medial canthus
drain through lac puncta into canaliculi
lac sac - nasolacrimal duct - inferior nasal meatus