Ciliary Body, Crystalline Lens, Iris
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| What are the two main functions of the ciliary body? | 1) secrete aqueous humor; 2) control accommodation of crystalline lens
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| How wide is the ciliary body? | approximately 6 mm wide
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| The ciliary body extends from the _________ to the ___________. | ora serata to the scleral spur
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| What is the outermost layer of the ciliary body? | Supraciliaris
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| What other name is the supraciliaris known as? | supraciliary lamina
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| Which part of the ciliary body is adjacent to the sclera? | supraciliaris
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| What is the supraciliaris made up of? | Loose, connective tissue arranged in ribbon-like layers
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| What three things does the supraciliaris contain? | pigmented melanocytes; fibroblasts; collagen bands
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| Why are the collagen bands in the supraciliaris important? | they allow the ciliary body to slide against the sclera without breaking
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| What is the flatter region of the ciliary body that extends from the posterior of the pars plicata to the ora serata? | Pars Plana
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| Which part of the ciliary body contains the ciliary processes? | The pars plicata
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| How many ciliary processes are in the ciliary body? | 70 to 80
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| What is the length of the ciliary processes? | 2 mm
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| What are the regions between the ciliary processes called? | valleys
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| The zonule fibers attach to the pars plana or the pars plicata? | Both
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| The pigmented epithelium of the ciliary body is continuous with? | Iris epithelium and the retinal pigmented epithelium
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| The non-pigmented epithelium is composed of what type of cells in the pars plana? | Columnar
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| The non-pigmented epithelium is composed of what type of cells in the pars plicata? | Squamous
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| Posteriorly the non-pigmented epithelium becomes...? | retinal nervous tissue
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| Which epithelial cells are active and secrete aqueous? | The non-pigmented epithelial cells
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| What type of tissue is the ciliary muscle made up of? | Involuntary, smooth muscle tissue
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| The ciliary muscle is used for...? | focusing at near
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| When the ciliary muscle contracts the lens gets a _______ front and back surface. | steeper
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| When the muscle contracts it takes the tension off of the ____________, allowing the lens to get rounder for ____________. | zonule fibers; accommodation
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| What are the three types of muscle fibers in the ciliary muscle? | Longitudinal; Radial; Annular
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| Which muscle type lies adjacent to the supraciliaris? | Longitudinal
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| Which muscle type is the middle transition? | Radial
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| What is the innermost region of the ciliary muscle? | Annular tissue
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| The ciliary stroma is highly vascularized, true or false? | true
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| What type of tissue is the ciliary stroma made of? | Loose, connective tissue
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| The ciliary stroma lies between which layers of the ciliary body? | Between the muscle and epithelial layers
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| What forms the core of each of the ciliary processes? | The ciliary stroma
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| Is the crystalline lens vascular? | No, it is avascular.
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| What is the location of the crystalline lens? | In the posterior chamber, anterior to the vitreous chamber.
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| Is the crystalline lens biconvex or biconcave? | biconvex
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| What is the thickness of the unaccommodated lens? | 3.5-5 mm
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| What is the diameter of the lens at infancy? | 6.5 mm
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| What does the diameter of the lens reach during the teenage years, and then doesn't change much? | 9.0 mm
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| How much does the thickness of the lens increase each year? | .02 mm
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| What is the power of the unaccommodated lens? | 20 diopters
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| What the eye accommodates it __________ the power of the lens. | increases
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| At what age do we have the max accommodative amplitude? | Ages 8-12
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| What is the max acommodative amplitue? | 14 diopters
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| At what age do you have zero accommodative power | 50
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| What is the lens capsule? | A transparent envelope that surrounds the entire lens
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| What is the lens capsule classified as? | A basement membrane
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| What is the capsule primarily made of? | collagen
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| The anterior capsule ________ with age. | Thickens
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| What is the anterior capsule secreted by? | anterior lens epithelium
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| The anterior lens capsule is how thick? | 1 mm
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| Does the anterior lens epithelium produce new cells? | Yes
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| The new cells in the anterior lens epithelium form the _______, when they elongate and the nuclei move with the cytoplasm. | lens bow
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| Old cells go towards the ________________? | embryonic nucleus
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| What are the primary lens fibers that form the very center of the crystalline lens? | Embryonic nucleus
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| When are the fetal nucleus fibers laid down? | Before birth
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| Which fibers are formed between birth and sexual maturation? | Adult Nucleus
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| When is the lens cortex formed? | After sexual maturity
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| Do cells in the lens get larger as the get older? | No, they shrink
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| What else happens to cells in the lens as they get older? | loose their nuclei; migrate towards the center; become compressed
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| What happens to the nucleus of the lens as it ages? | It becomes larger and less transparent
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| How much bigger is the lens at age 65, than at age 20? | 1/3 larger
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| What is the primary function of the lens? | Refracting light
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| In the center of the lens (light path) there are many or few cells? | Very few cells
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| What does the lens contain that allows it to be transparent? | An orderly arrangement of collagen fibers
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| What is the index of refraction of the lens? | 1.42
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| The crystalline lens transmits light including which wavelengths? | 400 to 1000 nm
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| The cornea absorbs wavelengths below ___nm? | 300
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| The lens absorbs wavelengths between ___ and __nm? | 300 and 400
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| Light greater than ___ nm will transmit to the retina. | 400
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| Any opacity of the crystalline lens is technically considered a ________? | cataract
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| What is the most common type of cataract? | Age related/senile
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| What are age related/senile cataracts linked to? | Long-term exposure of UV rays
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| What kind of cataracts are linked to German measles (rubella) in the mother during pregnancy? | Congenital
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| What can cause traumatic cataracts beside trauma to the eye? | Exposure to certain gasses
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| What is an opacity located in the embryonic or fetal nucleus? | Nuclear cataract
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| What is the most common type of nuclear cataract, characterized by a yellowing of the lens. | Senile Nuclear Sclerosis
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| Which type of cataract is an opacity located in the cortex? | Cortical
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| A cortical cataract is only problematic when...? | It spreads to the central vision
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| Where is a posterior subcapsular cataract located? | on the backside of the crystalline lens
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| What causes a posterior subcapsular cataract to form? | irregular migration of the epithelial cells
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| What has been linked to posterior subcapsular cataracts? | Long-term use of steroids
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| What type of cataract develops from elevated glucose levels and is characterized by decreased transparency. | Diabetic cataracts
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| What type of anesthetic is used for cataract surgery? | Local anesthesia
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| What type of incision is required for cataract surgery? | A small incision into the anterior chamber
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| What is opened during cataract surgery? | The anterior lens capsule
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| What is removed, and what is left intact during cataract surgery? | The epithelium and all lens fibers are removed, leaving only the capsule intact.
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| What is an IOL? | intra-ocular lens
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| What is the main function of the iris? | To regulate the light let in through the pupil
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| What divides the anterior chamber from the posterior chamber? | Iris
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| Where is the center of the pupil located in relation to the center of the iris? | Slightly medial (nasal) and inferiorly
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| The pupil can vary from _ to _ mm, depending on illumination. | 1 to 9 mm
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| The pupil is myotic (smaller) in what conditions? | brightly lit conditions
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| The pupil is mydriatic (bigger) in what conditions? | dimly lit conditions
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| What is the diameter of the iris? | 12 mm
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| Which epithelium lies nearest to the stroma in the iris? | Anterior epithelium
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| What is the anterior epithelium of the iris made uop of? | myoepithelial cells
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| The anterior epithelium is the only structure in the body that contains myoepithelial cells, true or false? | True
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| Which epithelium in the iris is heavily pigmented? | Posterior epithelium
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| What is the pupillary ruff (frill)? | When the epithelial cells curls around from the posterior iris to the anterior iris.
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| What does the pupillary frill encircle? | pupil
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| What color is the pupillary frill? | copper
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| The pupillary frill has a ________ appearance. | serrated
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| What is the collarette? | A circular ridge 1.5mm from the pupillary margin, that separates the iris into the ciliary and pupillary zones.
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| What is the outer edge periphery of the iris? | The iris root
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| How thick is the iris root? | .5 mm
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| What is the thinnest part of the iris? | iris root
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| The iris root joins the iris to the...? | ciliary body
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| What is iridodialysis? | a blunt trauma to the eye, where the root of the iris tears away from the ciliary body
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| What complications are caused from iridodialysis? | hemorrhaging and paralysis of the muscles in the eye
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| What does the stroma in the iris contain? | fibers and blood vessels and melanocytes which contain melanin
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| Where is the sphincter muscle located? | within the pupillary zone of the stroma
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| What type of cells is the sphincter muscle made up of? | smooth muscle cells
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| How wide is the sphincter muscle? | .75 to 1 mm
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| Contraction of the sphincter muscle causes...? | the pupil to constrict (myosis)
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| The sphincter muscle is innervated (activated) by the...? | parasympathetic nervous system
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| The parasympathetic nervous system is part of the _________ system, which means you don't have to think about it. | autonomic
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| Sympathetic nervous system, example dilation of the pupil, causes... | speeding up
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| The parasympathetic nervous system, example constriction of pupils, causes... | slowing down
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| The contraction of the dilator muscle...? | pulls the pupillary portion of the iris towards the root, enlarging the pupil
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| What is the contraction of the dilator muscle known as? | Mydriasis
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| Dilation is a ___________ muscle? | sympathetic
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| What are holes in the front of the iris that allow aqueous quick exit and entrance to the stroma of the iris. | crypts
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| What factor decide iris color? | The arrangement and density of connective tissue in the anterior border and stroma, and the amount of pigment.
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| If the iris is heavily pigmented, the anterior of the iris will appear...? | brown and smooth
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| Lighter irises will appear...? | Blue, grey, or green
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| What causes albinos to have red eyes? | There is no pigment in the epithelial layer
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| What is an area of hyper-pigmentation on someone's iris? | Nevus
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| What is it called when someone has two different colored irises, or if a portion of one's iris is different from the rest. | heterochromia
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| What is an iris synechiae? | An abnormal attachment of the iris surface to another surface.
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| What is an iridectomy? | A wedge-shaped, full thickness section of the iris is removed for aqueous flow.
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| What is an iridotomy? | Hole going through the iris to allow aqueous flow, performed by a laser.
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| Which is less invasive, an iridectomy or iridotomy? | iridotomy
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