Eyeball Flashcards
Midpoint of post curvature; pt between the optic disc and the fovia centralis
Post pole
The line that joins two poles
Anatomical axis
The direction of the light that enters the eyeball for you to be able to see an object;
Visual axis
Line that joins the midpoint of the lens and the fovea centralis
Visual axis
Most acute vision
Fovia centralis
Halfway bet ant and post poles
Equator
Divides the eyeball
Equatorial plane
divides eyeball into medial (nasal) and lateral (temporal) halves
Vertical meridional plane
Divide the eyeball into upper and lower halves
Horizontal Meridional plane
The wall of the eye has 3 layers, coats or tunics
Fibrous coat
(Middle) Vascular coat/ uveal tract
(Innermost) nervous coat
Outermost coat
Composed of connective tissue, collagen fibers
For protection and maintaining normal dimensions of eyeball
Fibrous coat
Middle coat
Where the blood vessels are located
Vascular coat
Uvea / uveal tract
Innermost coat
Retina; Sensory rceptor itself; made up of neurons
Nervous coat
2 parts of fibrous coat
- Sclera
2. Cornea
Post 5/6
Starts at optic nerve, ends at limbous
WHITE OF THE EYE (opaque)
Sclera
Ant 1/6
Most powerful refractive media
Transparent
Cornea
3 parts of vascular coat
- Choroid
- Ciliary body
- Iris
Going anteriorly, the choroid ends at the insertion of _____________
Recti muscle
Layer of blood vessels of graded caliber ( from large to medium to small) supported by connective tissue rich in melanocyte
Choroid
Absorbs light rays and prevents it from being reflected to the other parts of the eyeball
Choroid
Wedge shaped; ends at the limbous
Ciliary body
Thin diaphragm that rests on the ant surface of the lens
Iris
Central aperture
Pupil
Parts of the nervous coat
Retina
The retina is composed of how many layers?
10 layers
Innermost 9 are neural in nature
Cells of the pigmented layer of the retina
Pigment epithelium, non nervous,
SIMPLE CUBOIDAL EPITHELIAL CELLS
melanocytes
Termination anteriorly
Scallop
Termination of nervous retina
Ora serrata
Beyond the ora serrata the continuation of nervous retina will be __________
SIMPLE CUBOIDAL EPITHELIUM
will cover any aspect of ciliary body and iris
The inner lining of the ciliary and iris is a double layer of ____________
Neural and non neural simple cuboidal epithelial cells
Region of ciliary body
Pars ciliaris retina
Region of iris
Pars iridis retina
The continuaiton of the nervous retina is non pigmented over ___________, but reaching the _____ it becomes pigmented too
Ciliary body, iris
Sa ciliary body, only outer is pigmented
Sa iris, yung double layer is pigmented (inner)
Bends the light so that the focus falls exactly or close to the fovea centralis
Refractive media
Refractive media
Cornea
Aq humor
Lens
Vitreous
Most powerful refractive media
Cornea
Responsible for sharp central vision
Located in the center of the macula region of the retina
Fovea centralis
Not dynamic; gradually circulates ( found in both ant and post border of the eye
Aq humor
Flexible; assumes more convexity or flattened
Lens
Transparent gelatinous body of the chambers
Vitreous humor
Remnant of hyaloid artery
Hyaloid canal
Chambers of the eye
Anterior chamber
Posterior chamber
Viterous chamber
Bounded anteriorly by cornea, posteriorly by the iris and lens
Anterior chamber
The posterior chamber is bounded by
Ant: iris
Post: zonular ligaments of the lens / suspensory ligaments of the lens
The vitreous chamber is bounded by _____
Ant: lens and ligaments
Post: retina
Thickest posteriorly, fading anteriorly
Sclera
Why is the posterior part of the sclera its weakest spot?
It is perforated by fibers of cranial nerve 2, optic nerve
Junction bet cornea and sclera
Limbous
Thin loose vascularized connective tissue
It has episcleral veins
Episclera
Bulk of sclera
Collagen fibers, connective tissue
Transition zone bet sclera and choroid
Here you will see melanocytes and elspastic fibers
It you see this it means you are near the choroid
Lamina fuscia
5 layers of the cornea
ABCDE (ant-post, out-in)
- Ant epithelium
- Bowman’s membrane
- Connective tissue stroma (substancia propria)
- Descemet’s membrane
- Endothelium
Stratified sq wet; usual mucous membrane; rich in nerve supply; extra sensitive; u do your corneal reflex here; regenerates easily because it is epithelial, injuries are not a problem except if it involves B; cont with conjuctival epithelium
Ant epithelium
Basal lamina of ant epithelium
Fine collagen fibers
Resistant to entry of foreign bodies & MO
Scar formation when injured
Bowman’s membrane
Midpoint of cornea
Ant pole
