Hand-painted detail clearly shows coronary blood supply and drainage. Two-piece heart is bisected for internal and external heart anatomy study. Hand-painted structures show excellent detail. Clearly shows the semicircular canals, incus, eardrum, tensor timpani muscle, and inner ear mechanisms. View common pathologies such as adhesions, appendicitis, bacterial infection, cancer, Crohn's disease, diverticulitis, diverticulosis, polyps, spastic colon, and ulcerative colitis. Model also shows breast structures such as suspensory ligaments, fat tissue, lymph nodes, muscles, and ribs. Depicts common pathologies such as adenocarcinoma, cysts, fibroadenoma, and infiltrating scirrhus carcinoma. Model also depicts the muscular artery walls. One branch of the “Y” shows the beginnings of arterial occlusion. Oversized, sectioned artery shows the buildup of cholesterol deposits. Most models are for general anatomical study however, the artery, breast, colon, liver, skin cancer, and stomach models also depict pathologies.Īrtery Model. This task is discussed in the next part of Lesson 6.Each affordable anatomy model is removable from its base and comes with a one- or two-sided, color key card. The ultimate goal of such an anatomy is to allow humans to focus images on the back of the retina. This network of nerve cells is bundled together to form the optic nerve on the very back of the eyeball.Įach part of the eye plays a distinct part in enabling humans to see. There are as many as one million neural pathways from the rods and cones to the brain. The nerve impulses travel through a network of nerve cells. These rods and cones send nerve impulses to the brain. An adult eye is typically equipped with up to 120 million rods that detect the intensity of light and about 6 million cones that detect the frequency of light. The retina contains the rods and cones that serve the task of detecting the intensity and the frequency of the incoming light. The inner surface of the eye is known as the retina. By carefully adjusting the lenses shape, the ciliary muscles assist the eye in the critical task of producing an image on the back of the eyeball. These muscles relax and contract in order to change the shape of the lens. The lens is attached to the ciliary muscles. Unlike the lens on a camera, the lens of the eye is able to change its shape and thus serves to fine-tune the vision process. The crystalline lens is made of layers of a fibrous material that has an index of refraction of roughly 1.40. Light that passes through the pupil opening, will enter the crystalline lens. And in dim-light situations, the iris adjusts so as to maximize the size of the pupil opening and increase the amount of light that enters the eye. In bright-light situations, the iris adjusts its size to reduce the pupil opening and limit the amount of light that enters the eye. The iris is the colored part of the eye - being blue for some people and brown for others (and so forth) it is a diaphragm that is capable of stretching and reducing the size of the opening. Like the aperture of a camera, the size of the pupil opening can be adjusted by the dilation of the iris. ![]() Thus, as you sight at another person's pupil opening, no light is exiting their pupil and coming to your eye subsequently, the pupil appears black. Its black appearance is attributed to the fact that the light that the pupil allows to enter the eye is absorbed on the retina (and elsewhere) and does not exit the eye. The pupil is the black portion in the middle of the eyeball. Rather than being an actual part of the eye's anatomy, the pupil is merely an opening. After light passes through the cornea, a portion of it passes through an opening known as the pupil. The cornea has the dual purpose of protecting the eye and refracting light as it enters the eye. The cornea is a thin membrane that has an index of refraction of approximately 1.38. In the front of the eyeball is a transparent opening known as the cornea. ![]() ![]() The eye is essentially an opaque eyeball filled with a water-like fluid.
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