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CDC 1-2
Eyes
Question | Answer |
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The eye is a sphere-shaped structure, approximately 1 inch in diameter. Most of the eyeball itself is not visible, but rather is located within a socket in the skull. This socket is called the _____. | Orbit |
The _________ is located within the orbit on the side of the eye. | Lacrimal gland |
The outer portion of the eye is covered by two protective flaps (the upper and lower eyelids) comprised of ____, ____, ____, and ____ | skin, muscle, connective tissue, and conjunctiva. |
The _____ includes the cornea and the sclera. | outer tunic |
____ is the outer transparent covering of the eye. It is primarily composed of connective tissue. | Cornea |
The _____ is the white portion of the eye, which is made of a tough fibrous tissue that is resistant to stretching and tearing. | sclera |
The sclera is covered with a thin mucous membrane layer known as the ______, which also lines the inner surface of the eyelids | conjunctiva |
This layer has a rich supply of blood vessels. The _____ contains the choroid coat, ciliary body, iris, and lens. | middle tunic |
The _____ is the thickest part of the middle tunic. It extends forward from the choroid coat, and forms a ring around the anterior portion of the eyeball | ciliary body |
The ____ is composed of both connective tissue and smooth muscle fibers. These fibers give the eye the distinctive color that you can see from the exterior of the body. | iris |
The center opening of the iris is called the _____. | pupil |
The _____ is located posterior to the iris. This is a transparent portion of the eye that is held in position by fibers called “suspensory ligaments.” | lens |
The _____ contains only one primary structural component of the eye– the retina. | inner tunic |
The retina is composed of visual receptor cells called “______.” These receptor cells include two distinct types of receptor cells: rods and cones | photoreceptors |
The nerve fibers of the retina join to the optic nerve at an area called the ____. | optic disk |
True or False? The human eye contains approximately 100 million rods and 3 million cones. | True |
The _____ is the pathway of vision. It extends from the optic disk along nerve pathways to the brain. | optic nerve |
This chamber is filled with a watery fluid called “_______.” ______ also fills the space between the cornea and the lens to help provide nourishment to these parts. | Aqueous humor |
The______ is the area of the eye that is occupied by the lens. | posterior chamber |
The largest portion of the eye is the _____ (also referred to as the posterior cavity), which is located behind the lens. | vitreous body |
This substance is responsible for supporting the internal structures of the eye as well as ensuring that the eyeball maintains its round shape. | vitreous humor |
The eye is protected from exterior particles by the _____ and _____ . | eyelids and lacrimal glands |