The human immune system is the body's fundamental nerve center of defense. It also keeps a close protective watch over the activities and conditions of the body's organ systems at the cellular level. It is a system constituted by organ structures and the integrative biological mechanisms that they employ in order to identify external stimuli and prevent life-threatening pathogens, infected cells, or tumors from harming the body. The immune system launches an attack on a foreign intruder that often sabotage and cause destruction inside the body-disrupting the activities of the vital organs, attacking good cells and leaving the body vulnerable to sickness or debilitating ailments.
Simply put, the immune system prevents invaders from disturbing the human body and putting it in peril.
The primary aim is to protect the human body and preserve biological homeostasis among the organ systems. A foreign intruder from without cause instability to the biological systems of the body's internal environment and the immune system for its part is primed to be sensitive to even the slightest change happening deep within the human body. The immune system are like patrolling watchmen that keep an eye on the vicinity and are ready to defend the body when a perceived threat is identified and the type of response relative to the nature of the invading intruder is determined. When the system is alerted, they build a defensive barricade-antibodies, for example-that combat a bacterium, virus or even a tumor cell. This mode of defensive strike is highly organized in a controlled way for the immune system specifically targets only alien intruders that mean harm to the body or infected cells that can harm other healthy cells.
The destruction of healthy cells in the body is linked to the disastrous onslaught of diseases that are debilitating to human health and even fatal to human life. Many of these illnesses such as tuberculosis (or bacterial infection of the lungs) and AIDS (or Acquired Immune deficiency Syndrome) are highly infectious and wreak havoc to human populations at epidemic proportions. Viruses are molecular parasites that take over the human body and even mutate into several strains that can withstand the most advanced or powerful clinical drug designed to quell them. Some viruses in addition cause types of cancers such as in the case of cervical cancer due to Human Papillomavirus (HPV) infection. Cancerous cells, for their part, are wily enough to play tricks on the human body by flying under the system's radar so to speak and quietly yet rapidly replicating undetected.
The system's significance to human life is so vital and critical that modern science is driven to develop the best technology and pharmaceutical medicine that work with the natural autoimmune response of the body particularly in times of crisis.