HTHSCI 1H06 Chapter Notes -Central Retinal Artery, Electromagnetic Spectrum, Inferior Rectus Muscle
7 Oct 2013
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Document Summary
More than half sensory receptors in eyes. Cerebral cortex highly dedicated in processing visual information. Includes gamma rays, x-rays, uv rays, visible light, infrared radiation, microwaves, radio waves called electromagnetic spectrum. Eyes responsible for visible light detection (wavelengths 400-700nm) Object can absorb certain wavelengths of visible light and reflect others: green apple is green because it reflects mostly green light and absorbs most other wavelengths of visible light. Protect eyes from excessive light and foreign objects. Upper eyelid more movable than lower and contains in superior region the levator palpebrae superioris muscle. Twitch in eyelid associated with stress and fatigue. Protect eyeballs from foreign objects, perspiration, and direct rays of sun. Sebaceous ciliary glands release lubricating fluid into follicles. Infection of these glands causes swelling called sty. Group of structures that produces and drains lacrimal fluid or tears. Lacrimal glands supplied by parasympathetic fibers of facial nerves. Lacrimal fluid is watery solution containing salts, mucus, lysozyme (bctericidial enzyme)
