eyes (1) Flashcards
1
Q
Bones that make up the four-walls of the bony orbit:
A
Sphenoid
Zygomatic
Maxillary
Lacrimal
Frontal
Palatine
Ethmoid
2
Q
roof of thr otbit
A
Made up of the lesser wing of the Sphenoid and the Frontal bone
3
Q
Separates the intraorbital structures from the anterior cranial fossa
A
roof
4
Q
lateral wall
A
composed of the greater wing of the sphenoid and the zygomatic bone
5
Q
separates the eye from the temporal and middle cranial fossae
strongest among the walls
A
lateral wall
6
Q
Located along the anterolateral surface of the roof is the
A
Lacrimal Gland fossa
7
Q
medial wall of the orbit
A
formed by the sphenoid body, frontal process of the maxilla, orbital plate of the ethmoid, and the lacrimal bone.
8
Q
adjacent to the ethmoid air cells and nasal cavity
This wall houses the trochlear fossa superiorly and Lacrimal sac fossa inferiorly.
A
medial wall
9
Q
Because of the paper thin structure of the ethmoid bone, it was traditionally considered the lamina papyracea and the thinnest of all the walls.
A
medial wall
10
Q
floor of the orbit
A
composed of the orbital surface of the maxillary bone, orbital process of the palatine, and zygomatic bone
11
Q
separated from the lateral wall with the inferior orbital fissure from which important neurovascular structures gain access into the orbit and separates the eye from the maxillary sinus.
A
floor of the orbit
12
Q
The orbit is lined with a periosteum called
A
periorbita
13
Q
It is continuous with the:
periosteal layer of the dura mater posteriorly; and
pericranium at the orbital margin or rims superiorly and inferiorly
A
periorbita
14
Q
an important fibrous sheet that separates the eyelid from the infraorbital structures, important in delineating infections, tumors, and trauma
A
orbital septum
15
Q
T or F
the optic nerve is considered part of the CNS unlike the other cranial nerves.
A
T
16
Q
T or F
the superior lid margin covers half of the superior limbus while the lower lid margin covers a little part of the inferior limbus
A
False
the superior lid margin covers a little portion of the superior limbus while the lower lid margin just rests a little below it
17
Q
Eyelid retraction which exposes the sclera more on either part is common in what disease
A
thyroid eye disease
18
Q
Drooping of the lid narrows the palpebral fissure in a condition called
A
blepharoptosis
19
Q
Along the lid margins medially are the upper and lower lacrimal papilla and puncta which?
A
drains the tears
20
Q
parts of the conjunctiva
A
bulbar, palpebral, forniceal conjunctiva
21
Q
conjunctiva that Covers the globe
A
bulbar conjunctiva
22
Q
conjunctiva that Overlying the inner surfaces of both upper and lower lids
A
palpebral conjunctiva
23
Q
conjunctiva that Covers the recesses between the lids and the globe
A
forniceal conjunctiva
24
Q
The space between the bulbar and palpebral conjunctiva
A
conjunctival sac
25
Remnant of the nictitating membrane or the third eyelid in more primitive animals
plica semilunaris
26
Contains some dermal appendages like oil and sweat glands
caruncle
27
White fibrous coat
Connected to the central transparent cornea by the limbus
sclera
28
are paired superior and inferior flaps of highly specialized skin which serves to limit the exposure of the anterior eye from injury and light
eyelids
29
The aperture or opening between the upper and lower lids
palpebral fissure
30
The points where the upper and lower eyelids meet, also known as the palpebral commissures
MEDIAL CANTHUS AND LATERAL CANTHUS (pl. CANTHI)
31
In the front of the palpebral conjunctiva on the upper and lower lids is a dense band of connective tissue that serves as the main structure of the lids
tarsus
32
Contains glands that produce lipids that lubricates the margins and supplies the oily component of the tear film that prevents evaporation
tarsus
33
Along the margins are the lashes called cilia with their associated sebaceous glands
cilia
34
located on the super temporal anterior orbit secretes tears which serve to nourish, lubricate, and protect the eye through the bactericidal lysozymes
lacrimal glands
35
parts of lacrimal gland
orbital part and palpebral part
36
orbital and palpebral part separated from each other by the
levator palpebrae tendon
37
A percentage of the tears is also secreted by the
accessory lacrimal glands of Krause and Wolfring found along the conjunctiva
38
lacrimal outflow apparatus which start at the
lacrimal puncta of each papilla
39
T or F
Tears are distributed along the eye with each blink and are directed inwards through gravity and capillary action
false
outwards
40
open into canaliculi, that join together in the lacrimal sac and further down into the nasolacrimal duct and drain by the inferior nasal meatus in the nose.
superior and inferior punctae
41
The spilling over of tears, most commonly occurs secondary to a block in the nasolacrimal duct.
Epiphora
42
Tearing is stimulated by what nervous system and what nerve
by the parasympathetic nervous system through the facial nerve via the greater petrosal nerve to the nerve of the pterygoid canal and to the pterygopalatine ganglion.
also receives sympathetic stimulation via the superior cervical ganglion and joins the parasympathetic supply through the zygomatic nerve which is a branch of the maxillary nerve and brings them to the lacrimal branch of the ophthalmic nerve
43
suspensory ligaments
Tarsus
Medial and Lateral Palpebral Ligaments
Whitnall Ligament
Lockwood Ligament
44
extension of the periorbita along the orbital rims
important anatomical and surgical landmark in ophthalmology that delineates potential spaces in and in front of the orbital cavity
orbital septum
45
The fascial sheets of the globe surround the eye and are pierced by the muscles as they approach their scleral insertions and carry with them reflections of the fascia called
muscle sheet
46
connected to the orbital margins through the medial and lateral palpebral ligaments
tarsus
47
serves as the origin and attachment of the orbicularis oculi muscle
medial palpebral ligament
48
A sleeve of fibrous connective tissue which serves as a check ligament for the levator palpebrae superioris muscle and supports the upper lid and superior orbit
whitmall ligament
49
A transverse fascial structure that supports the eyeball inferiorly providing the framework for the inferior rectus and oblique muscles
lockwood ligament
50
The main suspensory apparatus of the eye is composed of the bulbar fascia that surrounds it called the Tenon’s capsule
tenon's capsule synonym is bulbar fascia
51
Transparent mucous membrane that covers the eyelids internally
Reflected onto the eyeball, where it is continuous with the bulbar conjunctiva
palpebral conjunctiva
52
Thin, transparent, and loosely attached to the anterior surface of the sclera (white) of the eyeball where it contains small, visible blood vessels.
bulbar conjunctiva
53
Very loose connective tissue layer
Potential space
Lies between the fascial sheath and the outer layer of the eyeball facilitating the movement of the eyeball within the fascial sheath
episclera
54
The tough opaque part of the fibrous layer of the eyeball
Serves as an attachment site for the extraocular muscles and comprises the posterior 5/6 of a globe
The anterior part is visible through the transparent bulbar conjunctiva
sclera
55
Anterior smaller transparent surface that protrudes slightly on lateral view
cornea
56
is cornea vascular or avascular
avascular
57
Because it is avascular, it is largely dependent on what structures
the peripheral capillaries along the limbus, the tears anteriorly, and the aqueous humor posteriorly for its nourishment and oxygen
58
One of the most highly innervated tissues in the body.
cornea
59
innervation of cornea
Supplied by the ophthalmic nerve
Branch of the trigeminal nerve
60
1 mm wide translucent circle that surrounds the cornea and is composed of mitotically active cells and capillaries that serve an important role in the health and healing capacity of the corneal epithelium
corneal limbus or the corneoscleral junction
61
the main vascular coat of the eye
middle uvea
62
Largest part
Its innermost choriocapillaris, which is adjacent and firmly attached to the retina, has the highest perfusion rate of all vascular webs in the body
Responsible for the red-orange reflex in fundoscopy and f photography
Supplies the outer light-sensitive retinal pigment epithelium and photoreceptor layers of the retina.
choroid
63
Ring-like thickening of the vascular layer posterior to the corneoscleral junction
Found anteriorly, located just beneath the limbus and provides attachment for the iris
Moore’s: provides attachment for the lens
ciliary body
64
Primarily controls lens accommodation and relaxation
ciliary body
65
part of the ciliary body that secretes acqeous humor
ciliary processes
66
Venous blood from ciliary body and the aqueous drain into the
scleral venous sinus
67
Lies on the anterior surface of the lens
Most anterior part of the uveal layer
Contains 2 involuntary muscles that control the pupillary aperture
Contractile diaphragm
iris
68
iris is a Contractile diaphragm with a central aperture called
pupil
69
nervous system causes of the dilator muscles to increase the pupillary size
mydriasis
70
may take up to _____ mins. for the pupil to dilate in response to low lighting
20
71
sphincter muscles to constrict the pupil
miosis
72
arrangement of dilator papillae and sphincter papillae
radially arranged and circularly arranged
73
Optic and non-visual inner
Sensory neural layer of the eyeball
Lights strike this structure from inside out
retina
74
portion of the retina that is Light-sensitive
Functions to absorb, refine, & analyze visual stimuli
optic portion
75
optic portion of the retina terminates anteriorly as
ora serrata
76
portion of the retina Anterior to the Ora Serrata, the retina continues over the 1) ciliary body; and 2) posterior surface of the iris to the margin of the pupil (Iridial)
non-visual portion
77
the inside, back surface of the eye. It is made up of the retina, macula, optic disc, fovea and blood vessels
fundus of the eye
78
The distinct lighter papilla on the retinal fundus
Transmits ganglion cell fibers
Allows entry of retinal vasculature
optic disc
79
This area corresponds to the physiologic BLIND SPOT
Since it has NO PHOTORECEPTORS, the optic disc is insensitive to light
optic disc
80
Found lateral to the optic disc (and between the superior and inferior temporal arcuate)
Latin for yellow spot (in which yellow color is only apparent when retina is examined w/ red-free light)
W/ special photoreceptor cones specialized for acuity of vision
macula
81
Found at the center of macula; a depression
Latin for central pit
fovea centralis
82
Found further anterior and continuous with the ciliary body
Delineated the termination of the optic retina
ora serrata
83
Branches from the Ophthalmic artery & Internal carotid artery
Where the anterior layers of the retina derive its blood supply from
central retinal artery
84
the transparent structures that bend (refract) light to focus it on the retina
refractive media of the eye
85
Primary refractory medium of eyeball (bends light to the greatest degree)
cornea
86
occupies BOTH anterior and posterior chambers of the eye
positioned anterior to the lens
Produced in the posterior chamber by ciliary processes of ciliary body
functions to provide nutrients to vascular lens and cornea
aqueous humor
87
A biconvex structure enclosed by the capsule
W/ the ciliary muscles relaxed, the zonules are held, flattening it and allowing far vision
lens
88
lens is anchored by
zonular fibers
89
found behind the lens
a transparent gelatinous substance
transmits light & supports the lens and retina
vitreous humor
90
Total refractive power of human eye
60 diopters
91
about 40 diopters = contributed by
cornea and tear film
92
remaining 20 diopters = from accommodation of
crystalline lens
93
Causes contraction of the ciliary muscle.
Muscular ring becomes smaller, reducing tension on the lens.
Lens thickens (becomes more convex) to focus on nearby objects (near vision).
Parasympathetic stimulation (via oculomotor nerve, CN III
94
Active process of changing the lens shape for near vision
accommodation
95
Accommodation typically becomes restricted after age
40
96
The 7 Extraocular Muscles (EOM)
Work in synergy to spontaneously open the eyelids and allow eye movement in the different directions of gaze
superior oblique
levator palpebrae superioris
superior rectus
medial rectus
lateral rectus
inferior rectus
inferior oblique
97
EOM that lifts eyelid
levator palpebrae superioris
98
Cause movement of one eye and movement of both eyes in the same direction
4 recti muscles + 2 oblique muscles
superior oblique
superior rectus
medial rectus
lateral rectus
inferior rectus
inferior oblique
99
The 3 Axes of EOM Movement
transverse axis
vertical axis
AP axis (anterioposterior axis)
100
What axis Moves the pupil superiorly (elevation/up).
Moves the pupil inferiorly (depression/down)
transverse axis
101
What axis Moves the pupil medially (adduction).
Moves the pupil laterally (abduction).
vertical axis
102
What axis Moves the superior pole of the eyeball medially (intorsion).
Moves the superior pole of the eyeball laterally (extorsion).
AP axis
103
origin of levator palpebrae superioris
Posteriorly at the lesser wing of sphenoid
104
insertion of levator palpebrae superioris
Attaches to the Whitnall's tubercle, continuing into:
The skin of the superior eyelid (anteriorly).
The superior tarsus (posteriorly).
105
attachment of this muscle forms the upper eyelid crease
levator palpebrae superioris
106
drooping of eyelids damage to levator palpebrae superioris
blepharoptosis
107
Rotates the superior pole of the eye medially (intorsion).
superior oblique
108
Rotates the superior pole of the eye laterally (extorsion)
inferior oblique
109
During an eye examination, a physician asks his patient to follow his finger:
Laterally?
to check the lateral rectus and abducens nerve
110
During an eye examination, a physician asks his patient to follow his finger:
superolaterally?
for the Superior Rectus
111
During an eye examination, a physician asks his patient to follow his finger:
inferolaterally?
to check the Inferior Rectus
Testing oculomotor nerves (SUP and INF)
112
During an eye examination, a physician asks his patient to follow his finger:
medially?
medial rectus
113
Directing the gaze Superiormedially , isolates the action of the ____ testing what nerve
action of the Inferior Oblique testing the Inferior division of the Oculomotor nerve
114
Directing gaze Inferolaterally isolates the ___ testing what nerve
uperior Oblique testing the Trochlear Nerve
115
paired contralateral muscles
yolk muscles
For example, when you look to the left:
The left lateral rectus (which pulls the left eye outward) contracts.
At the same time, the right medial rectus (which pulls the right eye inward) also contracts.
These two muscles are yoke muscles, working together to direct both eyes to the left.
116
simultaneous movements of both eyes in opposite directions to maintain binocular vision
vergeance
117
the orbital apex is composed of
Annulus of Zinn
Optic Canal
Superior Orbital Fissure
Inferior Orbital Fissure
118
The four recti muscles arise from the orbital apex from a common tendinous ring called the
annulus of zinn
119
following structures exit and enters the orbit
the optic nerve and ophthalmic artery in the optic canal
both superior and inferior divisions of the oculomotor nerve
the nasociliary nerve
the abducens nerves
120
The nerve supplying the EOMs pass through the
superior orbital fissure
121
The inferior ophthalmic vein exits the orbit through the
inferior orbital fissure
122
nerve that supplies the superior rectus (elevates the eye) and levator palpebrae (lifts the upper eyelid)
sperior dividion CN III
123
nerve that supplies the medial rectus (moves the eye inward), inferior rectus (moves the eye downward) and inferior oblique muscles (elevates the eye when looking inward and rotates it outward)
Inferior division CN III
124
the ciliary ganglion receives the following
Nasociliary root
Oculomotor Root
Sympathetic Root
125
the root that ciliary ganglion receives:
CNV1 Sensory Fibers (ophthalmic division of trigeminal nerve)
Nasociliary root
126
the root that ciliary ganglion receives:
Presynaptic parasympathetic fibers from CN III (inferior division of oculomotor nerve)
Oculomotor Root
127
the root that ciliary ganglion receives:
Postsynaptic sympathetic fibers from the internal carotid plexus
Sympathetic Root
128
T or F
CT scans are superior at imaging calcified structures like bone while MRI can afford better tissue detail.
T
129
ARTERIAL SUPPLY OF THE ORBIT
Ophthalmic artery from the internal carotid artery
Infraorbital artery from the external carotid artery
130
The structures in the orbit are DRAINED by the
Superior ophthalmic veins
Inferior ophthalmic veins
131
The choroid is supplied by what arteries
short posterior ciliary arteries
132
arteries that pass further forward into the eyeball to anastomose with anterior ciliary arteries from the muscular branches to supply the ciliary plexus
Two long posterior ciliary arteries
133
vein of the eye that empties into the cavernous sinus
central retinal vein
134
vein of the eye that drain the choroid into the posterior ciliary and ophthalmic veins
vortex veins
135
drains aqueous humor
scleral venous sinus
136
The superior and inferior ophthalmic veins pass through the
superior and inferior orbital fissures
137
sup and inf opthalmic veins drain into
cavernous sinus and pterygoid plexuses
138
Break in the orbital walls sparing the orbital rims.
most commonly along the medial and inferior walls and affecting the muscles and vasculature adjacent to them
blowout fracture
139
results from the herniation of orbital soft tissues from the defect as seen in the aerated maxillary sinus
teardrop sign
140
May arise primarily from the orbit or from adjacent sinuses
Commonly from:
Middle cranial fossa through the superior orbital fissure
Temporal & infra-temporal fossa through the inferior orbital fissure
orbital tumors
141
forward displacement of the eye
exopthalmus
142
Causes ptosis by interrupting the sympathetic innervation of the Müller M [also known as the superior tarsal muscle (STM)]
horner syndrome
143
Injury to the oculomotor N interrupts supply to the levator palpebrae superioris (LPS) M
CN III palsy
144
Inflammation of any of the 100 upper or 50 lower tarsal & sebaceous glands of the eyelids
HORDEOLUM/CHALAZIA
145
cause of chalazia projecting internally cause
Significant foreign body sensation
Astigmatism
146
cause of chalazia projecting externally cause
Pain
Swelling of the overlying skin
147
When conjunctival vessels become congested & hyperemic, as in from infectious or inflammatory causes, we describe them as being “injected.”
May be contagious from:
Viral
Bacterial
Allergic
conjunctivitis
148
The term _____ refers to the appearance of blood vessels that are dilated, congested, or filled with an increased amount of blood.
injected
149
Because the bulbar conjunctiva is loose over the sclera, it forms a potential space in which blood may clog.
SUBCONJUNCTIVAL HEMORRHAGE
150
what days of development?
Optic primordium appears in neural folds (1.5–3.0 mm)
Two optic bits derived from neural ectoderm develop on either side of the midline & eventually form the optic vesicles
The narrow neck of these vesicles directly connects the optic vesicle & the developing forebrain
22 days
151
What days of development?
Optic vesicle evaginates
Neural crest cells migrate to surround vesicle
25 days
152
What days of the development?
Vesicle induces lens placode
28 days
153
What days of development?
Eyelid folds appear
4-5 weeks
154
What days of development?
Invagination of optic & lens vesicles occurs
Once the optic vesicle touches the inner aspect of the surface ectoderm, the vesicle invaginates to form a bi-layered optic cup.
Hyaloid A enters the eye via embryonic fissure
Closure of embryonic fissure begins
Pigment granules appear in retinal pigment epithelium
Primordia of LAT rectus & SUP oblique M grow anteriorly
Eyelid folds meet & fuse
2 months
155
What days of development?
Retinal differentiation begins with nuclear & marginal zones
The inner layer forms the neural retina
The outer layer forms the retinal pigment epithelium
Migration of retinal cells begins
Neural crest cells of corneal endothelium migrate centrally → corneal stroma follows
Cavity of lens vesicle is obliterated
Secondary vitreous surrounds hyaloid system
Choroidal vasculature develops
Axons from ganglion cells migrate to optic N
Glial lamina cribrosa forms
Bruch membrane appears
2 months
156
Stage of development?
Precursors of rods & cones differentiate
Anterior rim of optic vesicle grows forward → ciliary body starts to develop
Sclera condenses
Vortex veins pierce sclera
3rd month
157
Stage of development?
Retinal vessels grow into nerve fiber layer near optic disc
Folds of ciliary processes appear
Iris sphincter develops
Descemet membrane forms
Schlemm canal appears
Hyaloid system starts to regress
Glands & cilia develop
4th month
158
Stage of development?
Photoreceptors develop inner segments
Choroidal vessels form layers
Iris stroma is vascularized
Eyelids begin to separate
5th month
159
Stage of development?
Ganglion cells thicken in macula
Recurrent A branches join the choroidal vessels
Dilator M of iris forms
6th month
160
Stage of development?
Outer segments of photoreceptors differentiate
Central fovea starts to thin
Fibrous lamina cribrosa forms
Choroidal melanocytes produce pigment
Circular M forms in ciliary body
7th month
161
Stage of development?
Anterior chamber angle completes formation
Hyaloid system disappears
8th month
162
Stage of development?
Retinal vessels reach the periphery
Myelination of fibers of optic N is complete to lamina cribrosa
Pupillary membrane disappears
9th month
163
When there is an interruption of the complete closure of the embryonic fissure
True _______ are located “below” since the embryonic fissure closes inferiorly
colombomas
164
In the developing retina, the layers are separated by an
intraretinal space
165
The retinal pigment epithelium is adherent to the choroid, but the neural retina is not firmly attached. Thus, the layers can be separated during trauma, causing a tear or a break in the retina
rhegmatogenous retinal detachment
166
when fluid collects between the layers as in
serous retinal detachment
167
Form when there is a loss of the clarity of the crystalline lens for multiple causes
The most common of which is the Normal Age Related changes that occur in the lens Fibers
Modern surgical approaches for cataract surgery involves removing the lens but leaving its capsule to receive a new synthetic implantable interocular lens
cataracts
168
Because we learned that the optic nerve is an extension of the Central Nervous Systems, increases in the intracranial pressure is transmitted in the subarachnoid space around it and reflects in the optic disc as Edema
This can be viewed doing Ophthalmoscope
pailledema
169
Blood can collect within the aqueous filled anterior chamber either from trauma or from a rupture of abnormal blood vessels in the body
hyphema
170
If pus or inflammatory cells collect in the anterior chamber.
hypopyon
171
One of the leading causes of irreversible blindness worldwide. Although etiologies can differ, the common final pathway is Optic Neuropathy that leads to a loss in the retinal ganglion cells, and eventually loss of vision
glaucoma
172
Happens when aqueous outflow is blocked while production continues, resulting in the build up of pressure, and compression and apoptosis of the inner retinal layers, arteries, and optic nerve fibers
angle closure glaucoma
173
double vision cause of the loss of the fusing ability of the eye
diplopia
174
Presents as an eye that’s down and out with ptosis because of the loss of innervation of the levator palpebrae superioris with unopposed action of the orbicularis, lateral rectus, and superior oblique muscles
The pupil may also be dilated because of the interruption of the parasympathetic supply
occulomotor palsy
175
Lateral Rectus Paralysis
Presents as Esotropia or adduction because the medial rectus is unopposed
Specific Palsies can be isolated with a good physical examination
abducens nerve palsy
176
The drainage and supply of the retina may be obstructed causing damage to the neural retina and resulting in frank and often sudden blurring of vision
Presents as retinal pallor and arteriolar narrowing with a characteristic cherry-red spot
Central Retinal Artery Occlusion
177
Presents with signs of congestion such as an edematous disc, tortuous veins and Hemorrhage
Recall that the central fovea is thin and devoid of almost all other retinal layers, allowing the intact choroidal layer, supplied by ciliary arteries, to show through.
Central Retinal Vein Occlusion
178
What 3 bones make up the lateral wall of the orbit?
Greater wing of the sphenoid bone
Orbital Surface of zygomatic bone
Zygomatic process of frontal bone
