Anatomy Flashcards
1
Q
OD
A
oculus dexter - right eye
2
Q
OS
A
oculus sinister - left eye
3
Q
optic fundus
A
- interior posterior surface of eyeball
- retina, optic disc, macula, posterior pole
- visible in ophthalmoscope
4
Q
posterior pole
A
retina between optic nerve and macular area
5
Q
sclera
A
- protective outer layer of eye; “white of the eye”
- continuous with cornea & sheath covering optic nerve
6
Q
vitreous
A
- transparent, colourless mass b/w lens and retina
- maintains shape and intraocular pressure
7
Q
aqueous
A
- clear, watery fluid that fills space b/w back of cornea and vitreous, bathing lens
- maintains intraocular pressure
- produced by ciliary processes
8
Q
ciliary processes
A
- epithelial portion of the ciliary body
- secretes aqueous fluid
- attachment site for suspensory ligaments of the lens (zonules)
9
Q
zonules
A
fibres that suspend lens from the ciliary body and hold it in position
10
Q
ciliary body
A
- tissue inside eye composed of 1) ciliary muscle and 2) ciliary processes
- involved in lens accommodation and control of intraocular pressure (epithelial protion makes aqueous)
- target for cycloplegic drops
11
Q
Iris sphincter
A
- makes pupil smaller
- parasympathetic NS
- near pupil margin
- stronger than dilator muscle
- cranial nerve III (oculomotor)
12
Q
Iris dilator
A
- makes pupil larger
- sympathetic NS
- periphery of iris
13
Q
alpha-1 receptors
A
- adrenergic (sympathetic)
- vasoconstriction of blood vessels
14
Q
alpha-2 receptors
A
- adrenergic (sympathetic)
- decrease output of norepinephrine
15
Q
beta-1 receptors
A
- adrenergic (sympathetic)
- increases heart rate
16
Q
beta-2 receptors
A
- adrenergic (sympathetic)
- bronchial dilation
17
Q
muscarinic receptors
A
- cholinergic (parasympathetic)
- decreases heart rate and constricts pupil (miosis)
18
Q
nicotinic neuronal receptors
A
- cholinergic (EXCEPTION: sympathetic)
- autonomic ganglia releasing epinephrine
19
Q
nicotinic muscular receptors
A
- cholinergic (parasympathetic)
- neuromuscular junction
- constriction of skeletal muscle
20
Q
VEGF
A
- vascular endothelial growth factor
- protein for growth of new blood vessels
21
Q
ora serrata
A
attachment of retina behind iris
22
Q
miosis
A
- pupil constriction
- sphincter muscle contracts, dilator relaxes
23
Q
mydriasis
A
- pupil dilates
- sphincter muscle relax, dilator contracts
24
Q
4 Rectus EOMs
A
- straight muscles
1. superior rectus
2. inferior rectus
3. medial rectus (toward midline - adduction)
4. lateral rectus (away from midline - abduction) - cause slight pull inwards when contracted
25
2 oblique EOMs
- angled muscles
1. superior oblique (from sphenoid bone, eye moves downward, incyclotorsion - in toward nose)
2. inferior oblique (from maxilla, eye moves upward; excyclotorsion, outward away from nose)
- cause slight eye protrusion when contracted
26
Annulus of Zinn
- tendinous sheath surrounding optic canal
| - gives rise to rectus EOMs
27
Levator palpebrae superioris muscle
- opens eyelid (voluntary or involuntary)
28
Cranial Nerve V
- trigeminal
- stimulates lower lid, lacrimal gland, skin of eyelid & conjunctiva
- abnormal - different sensations to face, forehead & eye
29
Cranial Nerve III
- oculomotor
- moves 4 of 6 ocular muscles
- stimulates pupil muscles
- damage causes inability to raise upper eyelid
- abnormal - ptosis, strabismus, dilated pupil
30
Cranial Nerve VII
- facial
- damage causes eyelids to NOT close
- abnormal - paralysis of facial muscles
31
conjunctiva (palpebral & bulbar)
- mucous membrane covering inner lid & eyeball
32
conjunctival fornices
- where bulbar & palpebral conjunctivas merge
33
canthus
- "corner" where eyelids meet
34
palpebral fissure
- space b/w upper and lower eyelids
35
lacrimal gland
- secretes lacrimal fluid (tears)
36
Ciaccio's & Krause's glands
- both produce tears
37
punctum
- opening in each eyelid (upper & lower) to canaliculus
38
canaliculus
- canal in tear drainage system
| - tear flow from eye to canaliculus to nasolacrimal sac to nasal cavity
39
basal tears
- lubricating
- give moisture, nutrition, defense, smooth optical interface for vision
- 3 layers: aqueous, mucin & oil/lipid
40
reflex tears
- mainly water, doesn't keep surface moist
| - due to stimulus ie) crying
41
anterior segment
- front 1/3 of eyeball
| - cornea & vitreous
42
limbus
- junction where sclera & cornea meet
43
anterior chamber
- fluid filled space b/w iris and innermost corneal surface (endothelium)
44
cornea
```
- anterior part of outer, fibrous coat of eyeball
circular, transparent & dome-shaped
- no blood vessels
- gets nutrients from tears
- gets oxygen from air
- high density of nerves
- needs dehydrated state
```
45
Six layers of Cornea
1 - Epithelium - exposed to enviro, fast growing, replaced every 7 days, refractive surface
2 - Bowman's membrane - randomly organized collagen fibers
3 - Stroma - regularly arranged collagen fibers, 90% of cornea's thickness
4 - Dua's layer - thin (controversy)
5 - Descement's membrane - basement layer; rigidity, barrier to water
6 - Endothelium - one cell thick, bathed by aqueous, keeps proper level of hydration by pumping out excess fluid, cannot regenerate so each cell gets bigger if some die
46
aqueous humor
- clear, watery fluid (like blood plasma)
- continuously produced by ciliary processes
- fills anterior & posterior chamber
47
trabecular meshwork
- mesh-like structure
- at iris-scleral junction
- filters and controls flow of aqueous
48
4 layers of Iris
1 - outer layer - pigment cells (colour)
2 - stroma - blood vessels, nerves
3 - muscle (dilator & sphincter)
4 - posterior epithelium - heavily pigmented, no light gets through
49
2 zones of Iris
1 - pupillary zone (inner)
| 2 - ciliary zone (outer)
50
posterior chamber
- space b/w back of iris and lens
| - filled with aqueous
51
posterior segment
- rear 2/3 of eyeball
| - everything behind the lens
52
vitreous
- jelly-like, transparent gel b/w lens & retina
- supports lens and holds retina in place
- NOT continuously replaced
53
retina
- thin, delicate holding photoreceptors
- 1 pigment layer
- 9 neural layers (rods & cones)
54
optic disc
- circular indentation where optic nerve enters eye
- blood vessels enter/exit
- depression in middle called cup
55
Cranial Nerve II
- optic nerve
- detection of light & vision
- abnormal - blindness
56
macula
- 5 mm of retina
- appears darker (choroid showing through)
- blood supply from ciliary arteries in choroid
57
Cranial Nerve IV
- trochlear nerve
- moves superior oblique muscle
- abnormal - double vision
58
Cranial Nerve VI
- Abducens
- stimulates lateral rectus muscle to pull eye laterally toward ear
- abnormal - double vision
59
uvea (uveal tract)
- pigmented vascular layers
| - iris, ciliary body & choroid
60
Visual Pathway
1 - Ganglion cells & nerve fiber layer (retina)
2 - Optic nerve
3 - Optic chiasm
4 - Optic tract, lateral geniculate body, optic radiations, visual cortex
