(b)++The+human+defence+systems+in+the+blood

The Human Defense System

In the human defense system, there are three different lines of defense which all protect the human body against diseases, infections, etc. __**Example:**__
 * __//Defense Lines://__ || __//What they do://__ || __//Examples://__ ||
 * First Line : Physical surface barriers || The physical surface barriers protect the body from infections and entries of pathogen cells. || Skin and mucous membranes ||
 * Second Line : Defensive cells with quick response || These cells respond the fastest to inflammations which cause an increased blood flow into a tissue. White blood cells defend the body against inflammations and other infectious diseases. Leukocytes can be found throughout the body, including the blood. || White blood cells (Leukocytes) ||
 * Third Line: || The body creates antibodies and other phagocytic cells to clear pathogens from an organism. They tag the pathogens and neutralize them so they can not harm the body. || Antibodies ||

This island during a war can be compared to a body when attacked by pathogens and other diseases. The red crosses are soldiers placed on the outside of the island to defend the island from all sides. In the body those are the physical surface barriers where the skin and other mucous membranes prevent the entry from pathogens. The blue crosses on the island are reinforcement soldiers that have to respond quick and replace the soldiers when they're defenseless. In the body those are the white blood cells which respond the fastest to inflammations. The white blood cells can be found throughout the whole body. The big green cross on the island can be called an 'assassin' who has a lot of power and clears enemies. There aren't a lot of them. In the body the green cross are antibodies which are created in little amounts and tag & neutralize pathogens.



 ** How your body can recognize foreign materials and invaders when they enter your body? **

In our human body, the Immune system is set up to destroy and get rid of things which are foreign to the body. If the body is invaded by fungus, viruses or bacteria, the job of the immune systems is going to recognize the invaders and destroy it. An example of molecules that could be recognized is antigens. Antigens are antibody-generators; proteins are surrounded in cells to keep it alive and functioning. The Immune systems will recognize the antigen on invaders. If the proteins are from you; it does will leave it alone and won’t attack it. The Immune system will attack the cells if the antigens are from a different organisms, it recognize it as foreign materials. Antibody is a special cell that is designed by your body to attacks just one type of invader. When the antibody recognizes the antigen (protein) on the foreign invader, then it will immediately attack it. The antibody goes and search around the human body for the right shape of antigen to fit and therefor to attack the invader because only one type of those can kill the other. Only type of antibody can attack, one type of invader. That’s why we have many types of antibodies and usually get each disease (like Chicken pox or Measles) once. White blood cells are in the Immune system. They are cells that are involved in defending against foreign materials and invaders (disease) inside the human bodies. They attack anything with a foreign antigen. Also, if a cell dies, it will stop making your own protein, so your defense system will no longer recognize it, and so will destroy it. If the human defense system goes wrong, the human body defense system could end upattack itself. The white blood cells will attack anything that it recognizes no matter if it from your body or from others. These could to lead to disease like diabetes.

[|Phagocytosis]: cellular process of engulfing solid particles by the cell membrane to form an internal phagosome (vacuole formed around a particle which is absorbed by phagocytosis).

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Immunity is a term that describes a human or state having enough biological defenses to avoid infections, diseases, or any other bad invasions. There are two types of immunity: Innate immunity: This is given to humans when they're born. It provides resistance through chemical, cellular, and physical approaches. Adaptive immunity: This is divided into two main types depending on how it was introduced. Naturally acquired immunity happens when there is contact with the disease itself. Artificially acquired immunity develops through actions like vaccination.