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45 Cards in this Set

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What is the optic disk?
It is also called the blind spot and it is the point in the retina where the optic nerve enters and it is not sensitive to light because it has no receptors. It is located by the posterior pole of the eye.
What is the ciliary body and what does it consist of?
It is a thickened portion ff the vascular coat between the choroid and the iris, and consists of:
1. ciliary ring
2. ciliary processes
3. ciliary muscle
Rates Per Minute
What are the Three Main Coats of the Eye?
1. External Layer (fibrous layer): fibrous coat, supportive function, inelastic

2.Middle Layer (vascular layer): vascular, highly pigmented

3. Internal Layer (neural layer): retinal coat
The external layer of the eye has what 2 constituents?
1. sclera: opaque white
2. cornea: transparent
Expelled (external): due to= SCorn
1. SOap
2. CounTry
The middle layer of the eye has what 3 constituents?
The middle layer in general helps to minimize glare from incoming eye.

1. choroid: melanized, brown, richly vascularized, nutritive

2. ciliary body: ciliary muscle, lens focus

3. iris: pigmented area, eye color
Please don't Mind(middle) that = I Called Collect!
1. Chorus Music
2. Call Less Frequently
3. I Paid Already
The internal layer of the eye has what 1 constituents?
1. neural retina: rods, cones (photoreceptors)
International (internal) = ReCord Rates Now
What is vitreous body?
It is the region behind the lens filled with water (99%), collagen, hyaluronic acid molecules and it holds the retina in place and provides support for the lens.
Very = WaCk Hours!
Describe Sclera?
It is a thick layer of DICT rich in fibers of collagen type I, arranged in parallel bundles, that protects,and maintains shape and it is a fibrous coat with supportive
function, that is inelastic and opaque white.

NOTE: It gives the white color to the eye and it is an attachment site for eye muscles.
Stubborn = Man DrOPS 1 Pinky Finger!
Describe Choroid?
It is a layer of loose connective tissue underneath the sclera and it has melanocytes – melanized, brown, absorption of stray light, also has blood vessels, richly vascularized,and nutritional.

NOTE: The choroid is a highly vascular layer (arrowheads) of connective tissue containing melanocytes that prevent the reflection of incident light.
Crappy = LaMe Book VaNished
What is located between the sclera and the choroid?
A layer of muscle
How is the retina and choroid related?
Many of the nutrients for the retina come from choroid blood vessels.
What are the 8 layers of Retinal Pigment Epithelium starting from the original direction of light?
1. Optic Nerve Fibers
2. Ganglion Cell
3. Bipolar cell
4. Cone
5. Rod
6. Pigment layer
7. Choroid
8. Sclera

Old Gangs Bring CRiP CarS
What are the 2 photoreceptor cells of the retina?
1. Cone
2. Rod
CRip
What are 5 functions of the retinal pigment epithelium?
1. It absorbs light, pigment granules

2. It prevents back reflection of light striking retina

3. forms part of blood-retinal barrier – tight junctions

4. sustains metabolism/pigment turnover of photoreceptors (so it has Rough ER and golgi involved in making melanin receptors)

5. Involverd in outer segment turnover – phagocytose shed discs
Really = ABsorB MaP
What is cilium?
They are long bipolar cells (about 9 microtubule duplexes) of photoreceptors in the retina that have flattened membrane discs or sacs on the outermost layer that are continously shed and phagocytised by the retinal epithelial cells.

NOTE: We have more rods than cones
1. What are 2 roles of Retina Pigment Epithelium (RPE)?

2. What are the 3 types of cells located in the Retina?
1.
A. It has tight junctions at the apical border to form the blood retina barrier.
B. It is involved in phagocytosing shed tips of rod outer segments and it also has melanin granules.

2. The three cell types are:
A. Ganglion cells
B. Bipolar Cells
C. Photoreceptor cells
What is unique about the papilla of optic nerve?
This is the same thing as the blind spot where you see nothing and all the afferent fibers of the papilla project and form the optic nerve. It is also where the axons of ganglion cells exit the eyeball and it has no photoreceptors.
What are 3 characteristics of the cornea?
1. Transparent
2. Avascular
3. most focusing of light occurs here
--It directs light rays to converge on retina
Cornt TAFfy song
Describe the cornea including its location and importance?
It is located at the anterior portion of the eye and it is continous with the sclera that comes from the posterior portion of the eye and it has a convex outer surface. It is the main site where light is refracting so the bending of light occurs here and then converge to the retina.
Describe cornea transplant and why the cornea is easily transplanted?
The corneal tissue for transplantation is taken from a donor shortly after death with the permission of the next of kin. Though most transplant procedures carry the risk of rejection of the transplant tissue or organ, the cornea has very limited blood supply, which greatly reduces this risk. Most corneal transplants function extremely well for many years.

Regarding cornea transplants , so you can take tissue from it and it has an endothelium and its cells do not turn over, so if the cells die, other cells grow over them, so there are holes in them.
This is the major reason for the transplants. Cornea damage can lead to blindness even though the photoreceptrs are ok, and it can self repair but if the injusry is too large, it is harder. But this are the most common form of transplant surgery so from dead ppl, right after they due like 5 hrs.
What are the 5 layers of the cornea starting from the anterior downwards?
The cornea has a fixed connectivity on the external surface which provides a good means to focus light rays and it has 5 layers:


1. Corneal epithelium : This is at the anterior aspect of the cornea (exposed to air) and it has stratified squamous epithelium that is nonkeratinized, has many free nerve endings, and capacity for regeneration.

2. Bowman's membrane: A type of basement membrane.

3. Stroma or substantia propia: It is the thickest layer of the cornea with DICT of collagen I, V, VI, and its DICT has materials that forms the lamellae.

4. Descemet's membrane: this is a thick elastic membrane.

5. Cornea endothelium: it is at the posterior aspect of the cornea (exposed to aqueous humor) and it has simple squamous epithelial cells and it pumps out fluid to give excessive hydration.
What is the function of lasik surgery?
It is used to restore vision by changing the shape of the cornea to remove the need for wearing glasses or contact lenses.
How is the stroma of the cornea arranged and what is the advantage of this?
It has DICT that have lamellae that are densely packed and they change the direction of their collagen fibers on different levels. Due to this arrangement, light goes right through and has no chance to bounce off.
What is the iris?
It is a thin, contractile, circular, pigmented diaphragm with a central aperture, the pupil. As light passes, the size of the pupil is regulated by iris and a reflection of the movement of the iris.
What are the 2 types of muscle fibers in the iris?
1. sphincter pupillae (circular muscle fibers): they are innervated by parasympathetic fibers

2. dilator pupillae (radial fibers): innervated by sympathetic fibers
What other structure of the eye is the iris derived from?
The retina, which constitutes the posterior part of the iris and the inner lining of the ciliary body. As the retina moves forward, it forms 2 layers, the iris and the ciliary body.
What does the ciliary processes secrete and where does the secretion drain into?
They secrete aqueous humor from their epithelium, which drains into the canal of schlemm.
1. What is aqueous humor?

2. Describe the movement of aquueous humor?
1. It is a fluid similar to similar to CSF that is secreted by ciliary processes and it provides nutrients for the avascular cornea and lenses.

2. It passes through the pupil from the posterior chamber (btw the iris and the lens = non pigmented) into the anterior chamber (between the cornea and the iris = pigmented) and is drained into the scleral venous plexus through the canal of schlemm at the iridocorneal angle.
1. What is the suspensory ligament or ciliary zonule?
1. It is a ringlike fibrous membrane connecting the ciliary body and the lens of the eye and holding the lens in place.
1. What does the iris consisting of?

2. Describe the outer covering layer of the iris?

3. Describe the inner layer of the iris?

4. What is the role of the Dilator and constrictor (sphincter) pupillary muscles?
1. a core of loose connective tissue that is highly vascularized in certain regions.

2. It is the anterior chamber and it is heavily pigmented to protect the eye’s interior from an excess of light.

3. It contains no pigmented cells.

4. They control the diameter of the pupil.
What determines eye color?
Melanization in the stroma
What is the role of the ciliary muscles?
They are used in accomodation, which is the automatic adjustment of the eye for seeing at different distances effected chiefly by changes in the convexity of the lens. So these muscles contract to pull the ciliary ring and ciliary processses, relaxing the suspensory ligament of the lens and allowing it to increase its convexity.
Describe the lens in terms of its structure?
It is a transparent (due to crystalline proteins) avascular biconvex structure that is enclosed in an elastic capsule and held in place by radially arranged lens fibers (elongated, protein-filled, loose organelles) or suspensory ligaments, which are attached medially to the lens capsule and laterally to the ciliary processes.
Describe the lens in terms of its function?
It is the highly elastic image focusing component of the eye and there is age-dependent loss of elasticity. The lens changes shape to bring into focus divergent or more parallel rays.
What is presbyopia?
A condition in which the power of accomodation is reduced and it is caused by the loss of elasticity of the crystalline lens. It occurs in advanced age and is corrected with bifocal lenses. Older ppl also get brownish pigments in theur eye.
Parent's Act Old
What is hyperopia?
This is farsightedness and in this condition, the focus of objects lies behind the retina.
High Five
Wnat is Myopia?
This is nearsightedness and it is a condition in which the focus of objects lies in front of the retina, due to elongation of the eyeball.
Morayo is New
What is cataract?
It is an opacity (milk-white) of the crystalline eye lens or its capsule, necessitating its removal. This results in little light to be transmitted to the retina, causing blurred images and poor vision.
Describe these 3 components found in the anterior portion of the eye:

1. The subcapsular epithelium

2. The lens capsule

3. The lens fibers
1. The subcapsular epithelium secretes the lens capsule, which appears stained in red.

2. The lens capsule is a thick basement membrane containing collagen type IV and laminin.

3. The lens fibers are below the subscapsular epithelium and they are cells that have lost their nuclei and organelles, becoming thin, elongated, and transparent structures.
Describe the process of accomodation by the lens?
This is when the lens flattens to focus on distant objects by pulling the suspensory ligaments, and it becomes a circular shape to accomodate the eye for near objectsd by contracting the ciliary muscles.
Describe accomodation in terms of:
1. close vision
2. distant vision
1.
- ciliary muscles contract
- suspensory ligaments relax
- lens becomes more round
- used for close vision

2.
- ciliary muscles relax
- suspensory ligaments contract
(pull)
- lens becomes more flat
- used for distant vision


NOTE: Spincter muscles, the ciliary bodies, and suspensory ligaments are involved. When the muscle contracts, it is like a spincter and it is smaller.
The ligaments attached to the ciliary body and they are connected to the lens, so there is tension on suspensory ligaments, and they are stretched, so when the muscles contract, the ligaments are relaxed.
If the lens has a round shape, the constrictor muscles are contracted then the ligaments are relaxed
Pulls the cells to become more flat for distant vision.
1. CCCC
2. CRDF
What is the canal of schlemm?
It is involved in the trabecular meshwork. It can be described as a circular canal lying in substance of the sclerocorneal junction of the eye draining the aqueous humor from the anterior chamber into veins draining the eyeball.
What happens in the trabecular meshwork - canal of schlemm?
It is when aqueous humor secreted into posterior chamber and flows into the anterior chamber and filters through trabecular meshwork
drains into Canal of Schlemm
What is Glaucoma?
It is a condition of opacity of the crytalline lens and it is characterized by increased intraocular pressure due to impaired drainage of aqueous humor (which is produced by the ciliary processses) into the benous system through sclemm's canal and impaired retinal blood flow, producing retinal ischemia or atrophy of the retina degeneration of the nerve fibers in the retina, particularly at the optic disk, and blindness.

EXTRA NOTES:
Glaucoma: clogging in meshwork, ↑ in intraocular pressure.

MORE NOTES:
If there is no drainage into CoS and the aqueous humor (AH) gets stuck in the trabecullar meshwork, there is glaucoma, so there is build up of AH and have increased pressure…so abnormal increase in intraocular pressure.
In the eye, some structres are inelastic like the sclera, and an increase of pressiure will not bend it.
What will be affected due to glaucoma?
The soft tissue of the eye like the optic nerves will be bent due to the pressure and you get blindness due to blockage, for examle, pigment granules might be released into the acqueous humor and cause the blockage
2 forms of glaucoma….open anger? Trabeculla close angula…trabecullar meshwork. There is no cure for it but treatments could help the eye to drain fluids or produce less fluids.
This is the leading cause of blindness in african americans and hispanics