Ocular Anatomy Flashcards
(127 cards)
0
Q
lines the inner aspect of the eyelids
A
Palpebral conjunctiva
1
Q
Thin, transparent vascular tissue that extends from the limbusto the mucocutaneousjunction of the eyelid
A
Conjunctiva
2
Q
covers the sclera
A
Bulbar conjunctiva
3
Q
Conjunctiva artery
A
anterior ciliary artery
4
Q
Conjunctiva inervated by
A
CN V (ophthalmic division
5
Q
Fine, thin, elastic layer which covers the sclera
Underneath the conjunctiva
Contains numerous blood vessels –> provide nourishment for the sclera
A
Episclera
6
Q
Thick outer coat of the eye
Normally white and opaque
Avascular& fibrous (collagen)
Continuous with the cornea anteriorlyand with the dural sheath of the optic nerve posteriorly
A
Sclera
7
Q
Transparent front “window”of the eye
Refracts light
A
Cornea
8
Q
nonkeratinized stratified squamousepithelium, regenerative ability
A
Corneal epithelium
9
Q
collagen fibers
A
Bowmans layer
10
Q
thick layer (90%) of regularly arranged collagen fibers (type 1), keratinocytes
A
Corneal stroma
11
Q
thin, strong layer, discovered in 2013
A
Dua’s layer
12
Q
thin acellularlayer that serves as the modified basement membrane of the endothelium, collage type IV
A
Descemet’s membrane
13
Q
monolayer of cuboidalcells, not able to regenerate, responsible for the corne’sdeturgescence
A
Endothelium
14
Q
The junction between cornea and sclera
A
Limbus
15
Q
Limbus May develop whitening as part of old age
A
Arcus senilis
16
Q
The space between the cornea and iris
A
Anterior chamber
17
Q
Anterior chamber Contains a watery fluid called
A
Aqueous humor
18
Q
Angle formed by the inner cornea and iris roots
Comprised of several structures that make up the eye’s drainage system
A
Anterior chamber angle
19
Q
eye’s drainage system
A
trabecularmeshwork
Schlemm’scanal
20
Q
middle, vascular layer of the eye
A
Uveal tract
21
Q
Colored part of the eye that controls the amount of light that enters the eye
A
Iris
22
Q
hole at the center of the iris that, size is controlled by the iris muscles
A
Pupil
23
Q
Accounts for the variety of eye colors seen
Dependent on the amount of pigment in the iris
A
Pigmented posterior surface of the iris
24
contains both dilator and sphincter muscles
Iris stroma
25
Contraction of the sphincter muscle
Pupil constriction
26
Contraction of the dilator muscles
Pupil dilation
27
Blood supply of the iris
Major circle of the iris
28
Sensory inervation of the iris
ciliary nerves
29
Circular opening at the center of the iris
| Adjusts the amount of light entering the eye
Pupil
30
Pupil constriction
parasympathetic activity –CN III
31
Pupil dilation due to
Sympatethetic activity
32
Structure of the eye that produces aqueous humor
Ciliary body
33
Contraction of the ciliarybodyChanges the tension of the
Zonular fibers
34
Ciliary body Change in tension leads to increased thickness of the lens allows eye to focus at near objects
Accomodation
35
Vascular, pigmented layer between the sclera(externally) and the retina (internally)
Provides blood supply to the outer retinal layers
Choroid
36
Biconvex structureRefracts and focuses light on the retina
Crystaline lens
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Crystalline lens Suspended in place by
Zonula fibers
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Crystalline lens anteroposterior
4.0 to 5.0 mm
39
Crystalline lens equatorial diameter
9.0 to 10mm
40
narrow space behind the iris and in front of the zonulefibers Space anterior to the crystalline lens
Filled with aqueous humor
Normally acellular
Posterior chamber
41
Large space behind the lens
Extends up to the retina
Approximately 4.5 cc in volume
Vitreous cavity
42
Vitreous cavity Filled with a transparent gel-like material called
Vitreous humor
43
Thin, semitransparent, multilayer sheet of neural tissue lining the vitreous cavity
Retina
44
10 layers of retina
1. Retinal pigment epithelium
2. Photoreceptor
3. Outer limiting membrane
4. Outer nuclear layer
5. Outer plexiformlayer
6. Inner nuclear layer
7. Inner plexiformlayer
8. Ganglion cell layer
9. Retinal nerve fiber layer
10. Inner limiting membrane
45
Retina blood supply
Central retinal artery
Branch of the ophthalmic artery
supplies inner 1/3 of the retina
Choroid
Supplied by the ophthalmic artery
Supplies outer 2/3 of the retina
46
Area of the retina responsible for fine, central vision
Macula
47
oval depression in the center of the macula
Approximately 2 disc diameters away from the optic disc
Slight inferior to the optic disc
Fovea
48
not really a peripheral nerve, it is actually a direct extension of the CNS 1.2 M axons 50 mm long Synapses at the lateral geniculatenucleus
Optic nerve
49
Blood supply of optic nerve
Circle of zinn-haller
Short PCA
Choroidalcirculation
Pialvasculature
50
1 mm long; 1.5 mm H; 1.8 mm V
| optic disc (visible by fundoscopy
Intra ocular
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25 mm in length; 3 to 4.5 mm in diam
lined by dura, arachnoid and pia mater
fuses at the apex of the orbit with periosteum and annulus of zinn
Intra orbital
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9 mm in length
| Firmly anchored to the bone (optic canal
Intra canalicular
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10 mm long (3 -16 mm)
| Just before it becomes the optic chiasm
Intra cranial
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Parietal and temporal lobes
Optic radiation
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Occipital lobe
Visual cortex
56
X-shaped structure wherein the medial fibers of both optic nerves decussate or cross to the other side
Suspended above the sellaturcica
Optic chiasm
57
Paired structures posterior to the optic chiasm
| Composed of lateral fibers from the ipsilateral optic nerve and medial fibers from the contralateraloptic nerve
Optic tract
58
Sensory relay nucleus
| Located in the thalamus
Lateral geniculate body
59
Paired structures that carry visual information from the LGB to the visual cortex
Pass thru the parietal and temporal lobes
Optic radiation
60
inferior fibers that pass through the temporal lobe looping around the inferior horn of the lateral ventricle
Meyers loof
61
Striate cortex or VI (Brodmann’sarea 17)
Occiptallobe
Responsible for image processing
Primary visual cortex
62
Bony cavity which contains the eye
“pear-shaped”with the optic nerve representing its stem Medial walls are parallel to each other, separated by the ethmoidaland spenoidal sinuses
Orbit
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Orbit
Volume: 30 cc
64
Roof of the Orbit -composed of
Frontal bone
| Lesser wing of the sphenoid
65
Contains the Lacrimal gland fossa
Orbital plate of frontal bone
66
Contains the optic canal
Lesser wing of the sphenoid
67
Depression located at 4mm from orbital margin
| Serves as the attachment of the cartilaginous pulley for the superior oblique muscle
Trochlear fovea
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Medial orbital wall composed of
Maxillary bone
Lacrimalbone
Ethmoidalbone
Lesser wing of the sphenoid
69
Contains thenasolacrimalcanal and the lacrimalsac
| paper thin medial wall : “lamina papyracea
Medial orbital wall
70
Lateral wall of the orbit
Zygomaticbone
| Greater wing of the sphenoid
71
Thickest and strongest
Lateral wall of the orbit
72
Site of attachment for: 1.Check ligament of lateral rectus muscle 2.Suspensoryligament of the eyeball 3.Lateral palpebral ligament 4.Aponeurosisof the levatorligament
Lateral orbital tubercle
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Roof of the maxillary sinus
Floor of the orbit
74
Floor of the orbit made up of 3 bones
Maxillary bone (blow-out fractures)
Palatine bone
Orbital plate of zygomaticbone
75
Arises from the orbital floor
| only extraocularmuscle that does not originate from the orbital apex
Inferior oblique muscle
76
Entry portal for all nerves and vessels to the orbit
| Site of the Annulus of Zinn
Orbital apex
77
ring of fibrous tissue comprised of the origins of the 4 rectiimuscles, superior oblique muscle, levator palpebrae
Annulus of zinn
78
Site of the Annulus of Zinn
Orbital apex
79
Foramen in the skull between the greater and lesser wings of the sphenoid bone
Superior orbital fissure
80
lacrimal& frontal branch of CN V Trochlearnerve (CN IV
Lateral outside the annulus of Zinn
81
Superior and inferior divisions of CN III Nasociliarybranch of CN V Abducensnerve (CN VI) Superior ophthalmic vein
Medial within the annulus of zinn
82
Optic nerve Ophthalmic artery
Optic canal
83
Maxillary & pterygoidparts of CN V
| Inferior ophthalmic vein
Inferior orbital fissure
84
Blood supply of the orbit
Ophthalmic artery
1st major branch of the intracranial ICA
85
enters the optic nerve 8-15 mm behind the globe; supplies the inner retina
Central retinal artery
86
supplies the lacrimalgland and the upper eyelids
Lacrimal artery
87
supplies the eyelid
Medial palpebral artery
88
Anterior segment of the eye
Long Posterior CiliaryArteries
89
Optic nerve, posterior surface of the eye
Short Posterior CiliaryArteries
90
Venous drainage of the orbit
Vortex veins,
Anterior ciliaryveinsCentral retinal vein
Superior and Inferior Ophthalmic Veins
Cavernous Sinus
91
Outer structures that protect the eyeball
Eyelids
92
Lubricates the eye surface
Meibomian gland within the tarsus
93
normally covers about 2 mm of the superior limbus
Upper lid
94
usually at the level of the inferior limbus
Lower lid
95
Exposed zone between the upper and lower eyelids
| In adults: 27 mm long and 8 to 11 mm wide
Interpalpebral fissure
96
more mobile than the lower eyelidCan be raised 15 mm by the levatorconjunctiva
Upper eye lid
97
Thinnest in the body
| Eyelid fold: due to insertion of levator aponeurosis near the upper border of the tarsus (may not be present in Asians
Skin
98
Has no fat content
Subcutaneous connective tissue
99
Punctum
Eyelashes arise from the anterior portion of the lid margin
Orifices of the meibomiangland are located along the posterior portion of the lid margin
Lid margin
100
Arranged in a concentric band around the interpalpebralfissure
Orbicularis oculi muscle
101
Inserts into the medial canthaltendon, orbital rim and corrugatorsupercilimuscle
Sphincter like action, voluntarily controlled
Orbital of orbicularis muscle
102
May be voluntary or involuntary (for normal and reflex blinking
Palpebral
103
Extension of the periosteum of the roof and floor of the orbit Attaches to the anterior surface of the levator muscle
Provides a barrier to spread of blood or inflammation
Orbital septum
104
Originates from a tendon that blends with the superior rectus and superior oblique muscles at the apex of the orbit
Levator muscle
105
Produces the eyelid fold
Levator aponeurosis
106
Elevates the eyelids
| Innervated by superior division of CN III
Superior tarsal muscle
| Muellers muscle
107
Consist of dense connective tissue not cartilage
| Attached to the orbital margin by the medial and lateral palpebralligaments
Tarsus
108
Part of tarsus
Modified holocrineglands --> oily layer of the tear film
Meibomian glands
109
Narrow, highly vascularized, crescent-shaped fold of conjunctival tissue
Rich in goblet cells
Analogous to the nictating membrane in lower animals
Plica semilunaris
110
Small, fleshy, ovoid structure
| Contains sebaceous glands and fine colorless hair
Carancule
111
Located in the frontal bone
Lacrimal gland
112
inner to the LA
Palpebral part of lacrimal gland
113
outer to the LA
Orbital part of lacrimal gland
114
Blood supply of lacrimal gland
Lacrimal artery
115
Flow of tears is mediated by pumping of the nasolacrimalsac by the orbicularisoculimuscle
Nasolacrimal sac
116
Opens into nasal cavity (inferior nasal meatus)
| Valve of Hasner
Nasolacrimal duct
117
Extraocular muscle
Six muscles per eye
4 rectimuscles Superior rectus Inferior rectus Medial rectus Lateral rectus
2 obliques Superior oblique Inferior oblique
118
away from the nose
Abduction
119
Towards the nose
Adduction
120
Upward
Elevation/supraduction
121
Downward
Depression/infraduction
122
rotation of the upper pole of the vertical meridian of the eye towards the nose
Intorsion/incyclotorsion
123
rotation of the upper pole of the vertical meridian of the away from the nose
Extorsion/excyclotorsion
124
Need to memorize
Medial rectus: adducts
Lateral rectus: abducts
Superior rectus: elevates, adducts, intorts
Inferior rectus: depresses, adducts, extorts
Superior oblique: intorts, abducts, depresses
Inferior oblique: extorts, abducts, elevates
125
Blood supply of extra occular muscle
Muscular branches of the ophthalmic artery
126
Nerve supply of extra ocular muscle
CN III: innervates superior, medial, inferior rectus muscles and the inferior oblique
CN IV: innervates the superior oblique
CN VI: innervates the lateral rectus
