the eye chapter 12 parts

the eyeball is made of:

the choroid, sclera and retina. From superficial to deep it is the sclera, then choroid, then retina.

sclera:

contains the cornea and it refracts light rays into the eye.

choroid:

contains ciliary body, iris, and pupil. The iris is the colored portion of the eye that contains smooth muscle. The lens is behind the iris.

retina:

contains the aqueous humor, cones, forearm, centralis, macula lutea, optic disk, retinal blood vessels, rods, and the vitreous body. the fovea centralis is in the middle of the macula lutea (yellow spot) and has the highest concentration of photo receptor cells. the optic disk is where blood vessels enter the eye; so it’s a blind spot.

muscles of the eye:

the eye contains oblique and rectus muscles. remember to make an L with your left hand and a slash with your right to remember the oculus sinister. The oculus dexter muscles are switched (all in anatomical position). oblique muscles pull at a slant, while rectus pulls straight. On oculus sinister, the medial rectus is on the anatomical left.

the eyelids:

cilia/eyelashes provide protection to the eye. The sebaceous glands make sure the eye and tears are moisturized.

conjunctiva:

mucous membrane lining under each eyelid and the anterior surface of the eyeball

lacrimal apparatus:

contains tears, lacrimal duct and gland, nasal cavity and nasocrimal duct. the lacrimal gland produces tears. then the lacrimal duct and sac drain fluid into the nasolacrimal cavity