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Unformatted text preview: of the hairs initiate a reflex action that closes the eyelids when the eyelashes are disturbed. • The lacrimal apparatus produces and drains tears. Tears (lacrimal fluid) are produced by the lacrimal glands, which lie above each eye (toward the lateral edge). In each eye, tears flow across the eyeball and enter two openings (lacrimal puncta) into lacrimal canals that lead to the lacrimal sac. From here, the tears drain through the nasolacrimal duct into the nasal cavity. Tears contain antibodies and lysozyme (a bacteria-destroying enzyme). • Six extrinsic eye muscles provide fine motor control for the eyeballs. These are the lateral, medial, superior, and inferior rectus muscles and the inferior and superior oblique muscles. The eyeball is a hollow sphere whose wall consists of three tunics (layers), shown in Figure 1....
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This note was uploaded on 11/10/2011 for the course PT 101 taught by Professor Staff during the Spring '10 term at Texas State.
- Spring '10