Eye and Orbit Flashcards
3 layers of the eye
Fibrous layer
Vascular layer
Neural layer
Fibrous layer of the eye
Sclera and cornea
Vascular layer of the eye
Choroid, ciliary body and iris
Neural layer of the eye
Retina
Slera is responsible for
Maintaining shape of the eye
Sclera continuous with
Cornea
What pierces the slcera
Optic nerve and central artery of the retina
Cornea is the
Anterior transparent outer layer of the ye
All vascular layer structures contain
Pigment
Choroid is____ and where does it lie
High vascularized and covered posterior 80% of eye
Ciliary body extends from
Ora serrata to outer edge of iris
Ciliary body contans
Ciliaris muscle
Iris controls
Size of pupil
How much light gets in
Muscular
Retina is origin of
Optic nerve
Retina is composed of
External pigmented and deeper multicellular layer
Retina ends at
Ciliary body near ora serrata
Ciliary processes
Most anterior part of ciliary body
Attach to zonular fibers of the lens
Contraction of ciliaris
Draws ciliary processes to relax the zonular fibers and cause lens to round up
Accomodation caused by
Contraction of ciliaris muscle causing relaxation of zonular fibers and causing lens to round up
Distant vision
Lens is stretched thin and ciliary muscle is relaxed
Zonular fibers under tension
Near vision
Parasympathetic causes ciliary muscles to contract
Zonular relaxes
Lens becomes more spherical
What divides eye into anterior and posterior chamber
Lens
Auqeous humor fills
Anterior and posterior chambers
Aqueous humor produced by
Ciliary processes
Path of aqueous humor
Ciliary process
Posterior chamber
Through pupil into anterior chamber
Sleral venous sinus
Glaucoma
Increased intraocular pressure
Compressed retina and optic nerve
Obstruction of auqeous humor drainage
Can cause glaucoma
4 things light must pass through
Cornea, aqueous humor, lens, vitreous body
Vitreous body
Fills region posterior to lens
Holds retina in place and supports len
Macula lutea
Center of optic axis
Specialized for visual activity
Macula lutea is )_____ to optic disc
Lateral
Fovea Centralis
Center of macula
Thinnest part of retina
Area of greatest visual activity in macula
Optic disc entrances nad exits
Exit of optic nerve and central vein of the retina
Entrance of the central artery of the retina
Also the blind spot
Papilledema is result of
Increased intracranial pressure
Veins of eye cannot drain
How is drainage of eye connected to brain
Optic nerve travels through optic canal and is surrounded by dura…will also have subarachnoid space connected to brain
Optic nerve is _____processes and passes through _____ to enter ______
Ganglion cell central
Optic canal
Middle cranial fossa
Bones of the orbit
Frontal Sphenoid Zygomatic Ethmoid Lacrimal Maxilla Palatine
Margin of orbit from
Frontal, zygomatic, maxilla
Laterally, eye is protected by
Fronal and zygomatic bones
Which walls of orbit are thinnest?
Inferior and medial
Blowout fracture of orbit
Results from direct blow
Medial and inferior wall fractures are most common
Periorbita
Orbital periosteum attached to bone