Human Body 3 Lines of Defense

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Human Body’s “Three Lines of Defense” The human body is very complex biological system. It is a multi system organism that has evolved for a very, very long time. The human body has fought off many diseases over the years and continues to fight more and more disease as the microorganisms find there ways of beating the human at its game of fighting all the disease out there. There are three lines of defense that the human body depends on in order to stay healthy. The three methods are mechanical & physiological defense, chemical defense and the human immune system. Mechanical / physiological defense is one of the most important and depended on defenses we take for granted as humans. This defense would be our skin, which we consider a mechanical barrier. One of the barriers we depend on is our skin is so tough when in intact that most microorganisms are unable to penetrate its barrier to infect the human. Unfortunately the skin is susceptible to animal and insect bites, which is where the skin becomes weekend and then its inability to protect us and because of this, the potential risk of infection increases. The skin has some mechanical characteristics that make it impermeable like necrobiosis, which is the shedding of dead skin. The skin has oils and some normal flora that inhibits the growth or spread of microorganism. Although our skin hosts many living microorganisms that defend against and fight foreign microorganisms that want to invade our bodies. The eyes and the hair in noses are other examples of the mechanical defenses for our bodies and work extremely hard. The eyes are constantly blinking and trapping dirt and wiping dirt at bugs away. The nose hair protects and filters a lot of the air we inhale and traps dirt and impurities before it could harm our lungs. Physiological defenses of our human body are when we regulate the heat by
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