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Ill-conditioned Pus
Pus is an exudate, typically white-yellow, yellow, or yellow-brown, formed at the site of inflammation during bacterial or fungal infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule, pimple or ''spot''. Description Pus consists of a thin, protein-rich fluid (historically known as ''liquor puris'') and dead leukocytes from the body's immune response (mostly neutrophils). During infection, macrophages release cytokines, which trigger neutrophils to seek the site of infection by chemotaxis. There, the neutrophils release granules, which destroy the bacteria. The bacteria resist the immune response by releasing toxins called leukocidins.Madigan, Michael T. and Martin, John M. Brock Biology of Microorganisms 11th ed. Pearson Prentice Hall. US. 2006: 734 As the neutrophils die off from toxins and old age, they are destroyed by macrophages, forming the viscous pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Eye
The human eye is a sensory organ, part of the sensory nervous system, that reacts to visible light and allows humans to use visual information for various purposes including seeing things, keeping balance, and maintaining circadian rhythm. The eye can be considered as a living optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially light tight except on the eye's optic axis. In order, along the optic axis, the optical components consist of a first lens (the cornea—the clear part of the eye) that accomplishes most of the focussing of light from the outside world; then an aperture (the pupil) in a diaphragm (the iris—the coloured part of the eye) that controls the amount of light entering the interior of the eye; then another lens (the crystalline lens) that accomplishes the remaining focussing of light into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
