why does our body need so many different mechanisms of defense and protection?
449010
Because it's a dangerous world out there. Predators and poisonous insects and plants, the scorching sun, the biting wind, viruses, paper cuts, fungal infections, mosquito borne diseases, fleas and ticks, flesh eating bacteria...Now that I stop and think about it, I'm not leaving the house anymore.
43911
there could be many causes such as environment factors, stress, diet or even allergy to certain substances...
210690
immune system \nThe immune system is the system of specialised cells and organs that protect an organism from outside biological influences. (Though in a broad sense, almost every organ has a protective function - for example, the tight seal of the skin or the acidic environment of the stomach.) When the immune system is functioning properly, it protects the body against bacteria and viral infections, destroying cancer cells and foreign substances. If the immune system weakens, its ability to defend the body also weakens, allowing pathogens, including viruses that cause common colds and flu, to grow and flourish in the body. The immune system also performs surveillance of tumor cells, and immune suppression has been reported to increase the risk of certain types of cancer.\n\nThe immune system is often divided into two sections:\n\nInnate immunity: Comprised of hereditary components that provide an immediate "first-line" of defense to continuously ward off pathogens. \nAdaptive (acquired) immunity: By manufacturing antibodies (a type of protein) and T-cells specifically designed to target particular pathogens, the body can develop a specific immunity to particular pathogens. This response takes days to develop, and so is not effective at preventing an initial invasion, but it will normally prevent any subsequent infection, and also aids in clearing up longer-lasting infections. \n\n\n\n\nStructure\nMost multicellular organisms possess an "innate immune system", generally comprising a set of germ-line encoded receptors to pathogens, that does not change during the lifetime of the organism. Adaptive immunity, in which the responses to pathogens change and develop during the lifetime of an individual, seems to have appeared somewhat abruptly in evolutionary time, with the appearance of chondrichthyes (cartilaginous or jawed fish).\n\nOrganisms that possess an adaptive immunity also possess an innate immunity, and with many of the mechanisms between the systems being common, it is not always possible to draw a hard and fast boundary between the individual components involved in each, despite the clear difference in operation. Higher vertebrates and all mammals have both an innate and an adaptive immune system.\n\n\nInnate immune system\nThe adaptive immune system may take days or weeks, after an initial infection, to have an effect. However, most organisms are under constant assault from pathogens, which must be kept in check by the faster-acting innate immune system. Innate immunity defends against pathogens by rapid responses coordinated through "innate" receptors that recognize a wide spectrum of conserved pathogenic components. Plants and many lower animals do not possess an adaptive immune system, and rely instead on their innate immunity.\n\nThe study of the innate immune system has recently flourished. Earlier studies of innate immunity utilized model organisms that lack adaptive immunity, such as the plant Arabidopsis thaliana, the fly Drosophila melanogaster, and the worm Caenorhabditis elegans. Recent advances have been made in the field of innate immunology with the discovery of toll-like receptors (TLRs) and the intracellular nucleotide-binding site leucine-rich repeat proteins (NODs), which are receptors in mammal cells that are responsible for a large proportion of the innate immune recognition of pathogens.\n\nIn 1989, prior to the discovery of mammalian TLRs, Charles Janeway conceptualized and proposed that evolutionarily conserved features of infectious organisms were detected by the immune system through a set of specialized receptors, which he termed pathogen-associated molecular patterns (PAMPs) and pattern recognition receptors (PRRs), respectively. This was a remarkable insight at the time but was only fully appreciated after the discovery of TLRs by the Janeway lab in 1997. The TLRs now comprise the largest family of innate immune receptors (or PRRs). Janeway’s hypothesis has
849263
There are more than two listed below but you can pick the ones you like best:\nEnergy for movement using our muscles.\nEnergy needed to digest our food\nEnergy needed for the heart to pump blood\nEnergy needed for breathing\nEnergy needed for growth and repair of tissue.\nEven energy needed for thinking
433879
Your mind and body are connected.  Do a search on psychoneuroimmunology.  There has been a lot of research on how depression and anxiety can affect lymphocyte counts, recovery, and wound healing.
415334
It's a defense mechanism that is secreted from their joints to ward of potential enemies.
89179
immune systen is the defense system of the body and inflammation is a way of responding to various harmful stimuli. it is mediated at the cellular level and it involves a lot of complex processes and chemicals like histamine and the like. i think its bronchoconstriction that ur talking about, ya it could be inherited, environmental and immunological. Asthma is a good example.
759465
Our body is made of cells.  Through the food which we eat, we are providing nutrients to these cells.  So when we fall sick or injure ourselves, the nutrients will kick in and replenish the cells and restore them back to normal. The duration taken to heal thyself depends on the food we take, amount of rest we take and the seriousness of the injury/illness
817824
The human body has every thing it needs to kill any bacteria and virus.  Like Lyme or MS.  We have the cellular power to kill the bad pathogens.  \nHere is a website of some one who has signed testimony of his success in this.
1075351
organs are things that process fluids or minerals for us. skeletons and muscles dont do that, they support us and provide mobility.
604803
Our skin is the largest organ of our body. Skin serves several functions: it guards the underlying organs and muscles, it regulates our body temperature, it provides our sense of touch and it synthesizes vitamins D and B.\n\nThe skin includes parts like our hair and nails. In addition, there are several layers to skin, e.g., the epidermis and the dermis. Skin accounts for 15% of our body weight so you can see why it's called the largest organ in our body.\n\nThe above is basic information and you can already see how complex skin is. So there's lets to research and talk about when you're talking about skin.\n\nHope this helps.
1114610
The skin is one of the major organs. Cilia in the nose prevents inhalation, the normal bacteria in the body that live there, white blood cells in the bloodstream, eyelashes and tears in the eyes, etc, etc. Our bodies come with self-healing structures unless they are pushed beyond their limits and can no longer function properly.
91572
There are VAST amount of different types of MD. Each one attacks its own set of muscles. Check out the link from the source.
1177123
The germs one comes into contact with daily are familiar, assuming you spend your life in one particular geographic location, going about a regular routine. So your body gets to know those germs and learns how to defend against them, maybe even alters them in subtle ways as part of its defense. So then when you share utensils, food, etc., with another person, you are exposing yourself to unfamiliar germs, just as they are exposed to your (possibly) altered, unfamiliar germs. Your immune system has no prior information to help it fight these 'new' germs. But it will mount a defense nevertheless, and if you are relatively healthy, you will survive the encounter and your immune system will have an expanded database.
711322
It seems to be an ongoing battle. As mankind evolves, so do our skills against fighting illness. But as we get better at making drugs to fight these bugs the bugs are  fighting back and getting more resistant until we reach a point (sometime soon, i feel) where we are going to have to depend on our immune system - like we did wayyyyyyy back in the day!
154162
I guess it just gives your body time to rest. you organ's don't seam to work as hard so it give's the body time to heal it's self and rest up for the next day. This is just a guess mind you.
552465
To conserve body heat and energy.