1
Q
Cutaneous innervation of eyelid
A
- V1
- Supraorbital
- Supratochlear
- Infratrochlear
- Lacrimal
- V2
- Infraorbital
2
Q
Eyelid muscle
A
- Orbicularis oculi
- Colses eyelid
- CN VII
- Levator palpebrae superioris
- Opens upper eyelid
- CN III
- Superior tarsal (Mullers)muscle
- Elevates eyelid
- Smooth uscle
- Symapathetic control, T1, via superior cervical ganglion
- Ptosis
3
Q
Orbital Septa
A
- Extension of periostium
- Upper orbital septum continous with levator palpebrae superioris
- Lower orbital septum continous with tarsal plate (dense CT)
4
Q
Conjuctiva
A
- Thin membrane
- Protect eye from pathogens
- Facilitates occular movement
- Covers posterior surface of each eyelid and the eye
- Palpebral layer
- Bulbar or occular layer
- Fornical layer
5
Q
Lacrimal Apparatus
A
- Lacrimal gland
- Dividied into 2 parts by the levator palpebrae superioris
- Lacrimal sulcus
- Paired serous gland - produce tears
- Lacrimal puncta-openings
- Lacrimal canals or canaliculi
- Lacrimal sac
- Nasolacrimal duct
6
Q
Eye Structures
7
A
- Lens
- Pupil
- Anterior chamber
- Filled with aqueous humor
- Posterior auricular
- Aqueous humor
- Canal of Schlemm
- Drains aqueous humor
- Vitreous chamber
- filled with vitreous humor (gelly goo)
- Optic nerve
7
Q
Anterior Segment
Post segment
A
- Ant and post seperated by iris
- Filled with aqueous humor
- Made by cilliary body
- Drains into superior opthalmic vein via the canal of schlemm
- Intraocular pressure is measured here
- Posterior segment
- Called vitreous cavity
- Filled with vitreous humor
8
Q
3 Layers/tunics
A
- Fibrous tunic
- Vascular tunic or Uveal tract
- Neural tunic
9
Q
Fibrous Layer/tunic contents
A
- Sclera
- Surrounds post surface
- Gives strngth and structure, fibrous
- White along periphery
- Allows for muscle attachment
- Cornea (contact lays on this)
- Anterior surface
- Bends light
- Encases most of anterior chamber
- Sensory innervation by V1
10
Q
Vascular layer or uveal tract
Contents (attachmeents)
A
- Choroid
- Highly vascularized
- Extends from optic nerve to ciliary body
- Ciliary body
- Lens accomodation
- Parasympathetic CN III, ciliary ganglion
- Suspensory ligaments
- Attach ciliary body to lens
11
Q
Vascular layer or uveal tract
Contents
A
- Lens
- Post to iris
- Focusing/refracting light
- Iris
- Sphincter pupillae m
- Constrict pupil,
- Parasympathetic CN III
- Dilator pupillae
- Dilate pupil
- Sympathetic control
- Sphincter pupillae m
- Pupil
12
Q
Neural Layer
A
- Retina
- Innermost layer of eye
- Thin and highly vascularized
- Pigmented
- Neural cells, photoreceptors
- 3 specialized areas
- Optic disc
- Macula lutea
- Fovea centralis
13
Q
Ametropias
4
A
- Myopia
- Nearsightedness
- Image focused anterior to retina
- Hyperopia
- Farsightedness
- Image focused post to retina
- Astigmatism
- Nonsperical eye
- Image focus at multiple location
- Presbyopia
- Loss of elasticity in the lens
- Age related, reading glasses
14
Q
Retina parts
A
- Pigmented part
- thin outer layer
- Absorbs light to prevent it from bouncing around
- Neural part
- Thick inner layer
- Contains
- Photoreceptors
- Neurons
- Supporting cells
15
Q
Photoreceptors
A
- Rods
- Work in dim light
- Dont provide sharp or color vision
- Periphery of retina
- Cones
- Operate best in bright light
- High acuity
- Color vision
- Center of retina
16
Q
Organization of retina
A
- Rods and cones
- Horizontal cells
- Bipolar cells
- Amacrine cells
- Ganglion cells
- Converge at optic disc
- Become optic nerve
- Travels throuugh optic canal
17
Q
Macula lutea
Fovea centralis
A
- Macula lutea
- Lateral to optic disc
- mainly cones
- Fovea centralis
- Only cones
- Maximal visual activity
18
Q
Optic disc
A
- Blind spot, no rods or cones
- Unmyelinated axons
- Where central artery and vein enter and exit
19
Q
Bleaching
Night blindness
A
- Bleaching
- Rhodopsin breaks down into retinal and opsin
- Night blindness
- Deficiency of vitamin A
20
Q
Visual pathway photoreceptors to brain
A
- Message crosses 2 synapses before heading to brain
- Photoreceptor to bipolar cell
- Bipolar cell to ganglion
- Unmyelinated axons from ganglion converge on optic disc
- Penetrate wall of eye as optic nerve CNII
- Join at optic chiasm
- Travel through optic tract
- Travel to lateral geniculate of thalamus
- arrive at visual cortex of opposite occipital lobe
- Left to r lobe
21
Q
Walls of orbit
A
- Superior
- Frontal
- Lesser wing of sphenoid
- Inferior
- Maxilla zygomatic palatine
- Medial
- Maxilla
- Ethmoid
- Lacrimal
- Frontal
- Lateral
- Zygomatic
- greater wing of sphenoid
- Frontal
22
Q
Orbital margin bone
A
Frontal
Maxilla
Zygomatic
23
Q
Periorbital Fascia
A
- Periosteum of orbit
- Orbit is surrounded in fat
24
Q
Contents of superior orbital fissure
A
- SUp and inf branches of CN 3
- CN 4
- Lacrimal n V1
- Frontal V1
- Nasocilliary V1
- CN 6
- Sup opthalmic v
- Sympathetic fibers
25
Contents of optic canal
* CN 3
* Opthalmic artery
26
Contents of inferior orbital fissure
* Inf opthalmic v
* Infraorbital V2
* Zygomatic of V2
* Pterygopalatine ganglion branches
* Infraorbital vessels
27
Common tendinous ring
* CN 2
* Opthalmic a
* CN 3
* Nasociliary V1
* CN 6
*
28
Fascia Bulbi (Tenons Capsule)
* Thin capsule of fibrous CT
* Allows for movement, attachment of extraoccular muscles
29
Nerve supply to orbit
* Optic 2
* Occulomotor 3
* Trochlear 4
* Opthalmic V1
* Maxillary V2
* Abducens 6
* Autonomics
30
Arterial orbit
* Opthalmic a
* Branch from ICA, travels through optic foramen, inferior and lateral to optic nerve
* Crosses optic nerve to reach medial orbit
* Lacrimal
* Supratrochleat
* Supraorbital
* Ciliary
* Lacrimal
* Ant/post ethmoid
* Dorsal nasal
* Central retinal (in optic nerve)
31
Arterial supply of orbit from ECA
* Infraorbital a from Maxillary
* Angular a from facial
* Superficial temporal a from ECA
* Tranverse facial a
32
Venous drainage
* Supraorbital
* Angular
* Facial
* Superior opthalmic
* Inferior opthalmic
* Infraorbital
* Opthalmic veins drain into cavernous sinus
* Pterygoid plexus
