The Eye: The Complex Structures Of The Human Eye

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The human body creates detailed visual images using the complex structures within the eye. The eyes are a pair of spherical organs that originate in the human skull, they shape the input from the outside world and create and visual image we can see. Due to their spherical shape they recede into the skull about 80%, along with the complex muscles, innervating nerves, and many blood vessels of the eye. The eye is a delicate but strong organ with reparative qualities, and having the external accessory structures, and lacrimal apparatus, helps the organ function. The eye is composed of complex fibrous layers, a retina comprised of two layers, Lastly the neural layers, rods and cones, and the optic nerves are located in the human eyes. At first …show more content…
The choroid, ciliary body, and lastly the iris. The choroid is a detailed membrane the houses a large network of capillaries that supply oxygen and nutrients to the inner layers of the eye. The cells within the choroid layer are filled with pigment necessary to absorb light that goes into the eye. Allowing for the retina to process and interpret remaining rays to make an image. The ciliary body is located anterior to the choroid, it is made of smooth muscle and folds of epithelium muscle cover to make the ciliary process. The last and most anterior part of the vascular tunic is the iris, meaning colored part of the human eye. It is composed of two layers of pigment-forming cells, two groups of smooth muscle fibers, and many vascular and nervous structures. In the center of the iris is a black hole called the pupil, the iris uses smooth muscles- sphincter pupillae and dilator pupillae, that control how much or little light enters the …show more content…
The pigmented layer of the retina is directly internal to the chorio and is attached to it, providing vitamin A for the photoreceptor cells, moves oxygen and nutrients towards cells, and moves waste away from the cells. The organization of the three layers in the neural layer are more complex, as they contain photoreceptor layers, bipolar cells, and ganglion cells. The outermost layer is composed of two types of photoreceptor cells. Rods in the peripheral areas, which function in dim light, and cones in posterior part, that function in high intensity light and assist in color vision. Internal to the photoreceptor layer are the bipolar cells, then a thin layer of horizontal cells, that make connections between photoreceptor and bipolar cells. Ganglion cells make up the innermost layer, and amacrine cells help process information as it goes through bipolar and ganglion

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