Eye Test Three Flashcards
What is the Macula Lutea?
Yellow region surrounding the fovea, has the highest visual acuity
What is the fibrous tunic?
Slcera and cornea
What is the vascular tunic?
Choroid, Ciliary Body, and Iris
What is the inner tunic?
Retina
What is the Episcleral layer?
- Outer layer of the sclera
- loose collagen and elastic fibers
- Very vascular
- Attaches eyelid lining to sclera
What is the sclera proper?
- Made up of interlacing collagen fibers
- Attachment site for tendons of extrinsic eye muscles
- Collagen bundles are parallel to outer surface of slcera
What is the Lamina cribosa?
- Perforated disc of sclera
- Pass through for optic nerve
Posteriorly the slcera is continuous with what?
Dural covering of the optic nerve
Layers of the cornea?
- Corneal epithelium
- Bownan’s Membrane
- Corneal stroma
- Descements membrane
- Corneal endothelium
Describe the corneal epithelium.
- Stratified non keratinized squamous epithlelium
- HIgh mitotic activity in basal layer
Describe Bowmans Membrane.
- Part of fibrous tunic of cornea
- Acellular layer sepatates epithelium from stroma
- Randomly arranged collagen
Describe the Corneal stroma.
Thin layers of ordered arrays of collagen fibers
Describe Descemet’s Membrane.
- Part of the fibrous tunic Cornea layers
- Acellular layer of collagen bundles
- Separates stroma from endothelium
Describe the Corneal endothelium.
Single layer of large squamous cells
Identify.
- Corneal endothelium
- Descemet’s Membrane
- Corneal Epithelium
- Bowman’s Layer
- Stroma
Vascular Tunic?
Choroid and Ciliary body
What is the Choroid?
Part of the vascular tunic
- Extends anterior to ora serrata of retina
- Highly vascularized with loose CT
- provides nutrients to outer layer of retina, contains melanocytes, forms choriocapillary network
- Bruch’s (Glassy) Membrane: acellular fused basal laminae of choripcapillaris and pigmented retinal epithelium
What is the Ciliary Body?
Part of the vascular tunic:
- Wedge shaped expansion of the choroid periphreal to lens covered by a double layer of cells
- Innermost layer is continuous with pigmented retina
- Surface layer is from sensory retina
- Produces Aqueous humor
- Suspensory ligaments behind lens
- Ciliary muscles innervated by parasympathetic
If the lens is flattened what kind of vision does that help?
Far vision
If the lens becomes thicker how does that affect vision?
Good for close vision
What surface layer of cells produces aqueous humor in the Ciliary Body?
Nonpigmented layer of cells
Describe the Iris.
Part of the vascular tunic:
- Anterior to the lens and separates the anterior and posterior chambers
- Surrounds pupil
- Melanocytes
- Double layer of epithelium
- Inner is pigmented
- Outer is radially oriented myofilaments sympathetic innervation
- Concentric layer of myofilaments is parasympathetic innervation
What are the two divisions of the retina divided by the Ora Serrrata?
- Photosensitive region posterior to the ora serrata (largest)
- Nonphotosensitive region anterior to ora serrata