L9 Anatomy of the Eye and Optical Properties Flashcards
Cornea vs. Sclera?
Cornea:
- Transparent (Regular arrangement of collagen fibers)
- Avascular
- Richly Innervated
Sclera:
- Tough Fibrous
- Opaque (IRREGULAR collagenous structure => opacity)
- Provides structure/attachment for extraocular muscles
Three Layers of the Eye
- Fibrous Outer Layer (Outer Layer - Sclera/Cornea)
- Uvea (Middle, Vascualr Layer)
- Retina (Inner, Neural Layer)
Between CORNEA and IRIS is the _________________
Between CORNEA and IRIS is the Anterior Chamber
Contains aqueous humor (Secreted by ciliary epithelium)
Behind IRIS and containing the LENS is the _____________
Behind IRIS and containing the LENS is the Posterior Chamber
Contains aqueous humor (Secreted by ciliary epithelium)
Space behind the lens is the __________________
Space behind lens is Vitreous Chamber
*Acellular (Predominantly water)
- Contains collagen fibers (Clumping => Floaters)
Illustrate the histological appearance of cornea, lens and corneosclerotic junction?
Layers of the Cornea
Components of the Fibrous Layer?
Fibrous Layer (Structural)
- Sclera
- Cornea
Components of the Uvea?
Uvea (Vascular Layer):
- Choroid
- Ciliary Body
- Aqueous Humor
- Iris
- Lens
_________: Loose, vascular, connective tissue
- Between _______ and _________ (from ________ to ________)
- Thickest at ______, thinnest at ______
- Rich in ____________
Choroid: Loose, vascular, connective tissue
- Between RETINA and SCLERA (from optic nerve to ciliary body)
- Thickest at back, thinnest at front
- Rich in Melanocytes!!: Prevents reflection of light within the eye (in tandem w/ pigmented outer retina) vision issues common in albinism, lack pigmentation => light bounces around
_______________: Regulates the shape of the lens
- Lies between ________ and _________
- Connected to LENS BY __________________which emerge from _________________
Ciliary Body: Regulates the shape of the lens
- Lies between CHOROID and IRIS
- Connected to LENS BY SUSPENSORY LIGAMENTS which emerge from CILLIARY PROCESSES
Cornea and Lens are _________ => nutrient supply is via __________________
______________ secrete aqueous humous (w/ Glucose + Amino acids) => drains through TRABCEULAR MESHWORK to __________________
Cornea and Lens are Avascular => nutrient supply is via Ciliary Body
Ciliary Processes secrete aqueous humous (w/ Glucose + Amino acids)=> drains through TRABECULAR MESHWORK to Canal of Schlemm (Scleral Venous Sinus)
Describe the innervation/muscles that control the Pupil
Aperture created by the iris is controlled by TWO muscles under AUTONOMIC control:
Sphincter Pupillae (Closes):
- Contracts=> shrinks aperture, limiting amount of light entering eye
- Parasympathetically innervated. BLOCKED BY ATROPINE => Dilation
Dilator Pupillae (Opens)
- Contracts => opens aperture, allows more light to enter the eye
- Sympathetically Innervated
__________________:
- Clear elastic layer produced by ______________
- Composed of collagen and glycosaminoglycans
- Under constant tension => affects lens shape
LENS CAPSULE (LC):
- Clear elastic layer produced by LENS EPITHLIUM
- Composed of collagen and glycosaminoglycans
- Under constant tension => affects lens shape
_____________________:
- lens homeostasis (produces _______________)
- osmotic control
LENS EPITHELIUM (LE):
- lens homeostasis (produces LENS CAPSULE)
- osmotic control
____________________:
- Long, thin transparent cells arranged in laminae
- Oldest cells are found in ________:(Contain no organelles/nuclei)
LENS FIBERS (DLF):
- Long, thin transparent cells arranged in laminae
- Oldest cells are found in CENTER (Contain no organelles/nuclei)
_________________ pigmented area in center of optical axis containing the FOVEA at center and has ________ or more layers of retinal ganglion cells
MACULA LUTEA: pigmented area in center of optical axis containing the FOVEA at center and has TWO or more layers of retinal ganglion cells
Structure of the Retina:
○ ___________________(Cell bodies of Ganglion cells)
○ ____________________( Synapses b/n Bipolar Cells and Ganglia)
○ ____________________(Bipolar Cell Bodies)
○ _______________________(Synapses b/n Bipolar Cells & Photoreceptors)
○ _____________________(Photoreceptor Cell Bodies)
○ _____________________________(Area where light is sensed)
○ ______________________(Prevents reflection within eye)
Structure of the Retina:
○ Ganglion Cell Layer (Cell bodies of Ganglion cells)
○ Inner Plexiform Layer ( Synapses b/n Bipolar Cells and Ganglia)
○ Inner Nuclear Layer (Bipolar Cell Bodies)
○ Outer Plexiform Layer (Synapses b/n Bipolar Cells and Photoreceptors)
○ Outer Nuclear Layer (Photoreceptor Cell Bodies)
○ Outer Segments of Photoreceptors (Area where light is sensed)
○ Pigment Cell Layer (Prevents reflection within eye)
Shape of Lens Accomodation for NEAR vs. FAR target?
Describe the process of Accommodation
Relaxed Ciliary Body: exerts tension on Zonular Fibers attached to Lens Capsule => Lens Flattens (Far in Focus)
Accommodated (Contracted) Ciliary Body: slides forward relaxing Zonular Fibers => Lens Expansion (Near in Focus)
Accommodative response to focus on NEAR Object?
Accommodated (Contracted): Ciliary Body slides forward relaxing Zonular Fibers => Lens Expansion (Near in Focus)
Pupil Constricts => GREATER depth of field
Accommodative response to focus on FAR Object?
Relaxed Ciliary Body exerts tension on Zonular Fibers attached to Lens Capsule => Lens Flattens (Far in Focus)
What is the Refractive Error called?
Myopia: Nearsightedness
What is the Refractive Error called?
Hyperopia: Farsightedness
