Glossary
- Aqueous Humor
- watery fluid that fills the anterior chamber containing the cornea, iris, ciliary body, and lens of the eye
- Choroid
- highly vascular tissue in the wall of the eye that supplies the outer retina with blood (also called the choroid coat)
- Central Fovea
- exact center of the retina at which visual stimuli are focused for maximal acuity, where the retina is thinnest, at which there is nothing but photoreceptors
- Ciliary Body
- smooth muscle structure on the interior surface of the iris that controls the shape of the lens through the zonule fibers
- Cone Photoreceptor
- one of the two types of retinal receptor cell that is specialized for color vision through the use of three photopigments distributed through three separate populations of cells
- Conjunctiva
- a mucous membrane that lines the inner surface of the eyelid as well as part of the sclera. The part of the conjunctiva lining the eyelid is called the palpebral conjunctiva.
- Cornea
- fibrous covering of the anterior region of the eye that is transparent so that light can pass through it
- Extraocular Muscle
- one of six muscles originating out of the bones of the orbit and inserting into the surface of the eye which are responsible for moving the eye
- Fibrous Tunic
- outer layer of the eye primarily composed of connective tissue known as the sclera and cornea
- Iris
- colored portion of the anterior eye that surrounds the pupil and contains circular and radial muscles that regulate the size of the pupil.
- Lacrimal Gland
- gland lateral to the orbit that produces tears to wash across the surface of the eye
- Lens
- component of the eye that focuses light on the retina
- Neural Tunic
- layer of the eye that contains nervous tissue, namely the retina
- Opsin
- protein that contains the photosensitive cofactor retinal for phototransduction
- Optic Disc
- spot on the retina at which RGC axons leave the eye and blood vessels of the inner retina pass
- Optic Nerve
- second cranial nerve, which is responsible visual sensation
- Photoisomerization
- chemical change in the retinal molecule that alters the bonding so that it switches from the 11-cis-retinal isomer to the all-trans-retinal isomer
- Photoreceptor
- receptor cell specialized to respond to light stimuli
- Pupil
- open hole at the center of the iris that light passes through into the eye
- Retina
- nervous tissue of the eye at which phototransduction takes place
- Retinal
- cofactor in an opsin molecule that undergoes a biochemical change when struck by a photon (pronounced with a stress on the last syllable)
- Rod Photoreceptor
- one of the two types of retinal receptor cell that is specialized for low-light vision
Sclera - white of the eye
- Scleral Venous Sinus
- small opening found at the junction of the cornea and sclera that drains aqueous humor (formerly called the Canal of Schlemm); if this is blocked the aqueous humor cannot drain and this causes glaucoma, which increases the pressure and therefore pain in the eye
- Vascular Tunic
- middle layer of the eye primarily composed of connective tissue with a rich blood supply
- Vitreous Humor
- viscous fluid that fills the posterior chamber of the eye
Grant and Other Information
Except where otherwise noted, this work by The Community College Consortium for Bioscience Credentials is licensed under a Creative Commons Attribution 4.0 International License.
Text from BioBook licensed under CC BY NC SA and Boundless Biology Open Textbook licensed under CC BY SA.
Other text from OpenStaxCollege licensed under CC BY 3.0. Modified by Alice Rudolph, M.A., Andrea Doub, M.S., Dr. Kim McMasters, D.C. and Amy Baugess, M.S. for c3bc.
Instructional Design by Courtney A. Harrington, Ph.D., Helen Dollyhite, M.A. and Caroline Smith, M.A. for c3bc.
Media by Brittany Clark, Jose DeCastro, Jordan Campbell and Antonio Davis for c3bc.
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