Portage Learning A&P 2: Module 3

Portage Learning A&P 2: Module 3 What are the special senses? smell, taste, vision, hearing, equilibrium special senses have specialized organs with specialized receptor cells touch somatic sense that doesn't have specialized sense organs, just general receptors from nerves with modified dendrites. Pressure, vibration, pain, heat outer layer of eye sclera and cornea sclera outer fibrous layer on the posterior portion of the eye. Referred to as "white of the eye" Cornea anterior outer fibrous layer of the eye, transparent. Where light enters aqueous humor fills the space between the lens and the cornea middle layer of eye choroid, ciliary body, iris Choroid middle, vascular layer of the eye, between the retina and the sclera. Dark colored. Prevents light from dispersing thru the eye Ciliary Body Muscle on the anterior portion of the eye (middle layer) that allows the lens to change shape and enables focus Iris anterior to the ciliary; round and colored portion of the eye. Controls the amount of light entering the pupil How does the iris control light entering the eye? It uses muscle fibers to contract or dilate based on the amount of light in the environment inner layer of eye retina Retina contains photoreceptors (rods and cones) Rods photoreceptors that are stimulated in dim lighting Cones photoreceptors that detect color and help us see sharp and colorful images Lens Posterior to iris and pupil Vitreous body chamber on the internal portion of the eye that is filled with vitreous fluid Vitreous fluid holds the retina in place to the choroid