Immunity and The Human Body
The Body's Defense System
The body's firs line of defense is a formidable array of physical and chemical barriers. When these barriers are breached, the body's immune system take action. Typically, when the body has been invaded by a foreign organism, an elaborate response is activated primarily immune system and the inflammatory system.
Immunity
Immunity is acquired after an infection has occurred within the human body. Typically, it is the survival that often confers immunity; meaning, a person who has had a specific infection will never get the same illness again because of lymphocytes. These special cells are made of memory T and B cells. If the same antigen (or illness) enters or is exposed to the same immune system, the lymphocytes will recognize and destroy the antigens before illness is initiated. This leads us to what is known as "acquired memory", which is the ability of the lymphocytes to recognize antigens.
Immunity is established when the body produces mechanisms responsible for defending against infection; specific defense against specific pathogens.
Acquired memory is the body's ability to mobilize the cellular memory of an attack by a pathogen to throw off subsequent attacks; this can be done through vaccination and through the normal immune response.
The Innate and Adaptive Systems
Immunity involves both specific and nonspecific components. The nonspecific components act either as barriers or as eliminators of wide range of pathogens irrespective of antigenic specificity. Other components of the immune system adapt themselves to each new disease encountered and are able to generate pathogen-specific immunity. The adaptiveness can better be described as two components; innate immunity and adaptive immunity. The innate immune system is also known as the nonspecific immune system, which provides the first line of immunological defense against infection. The molecules and the receptors of the immune system provide a broad range of protection, so that it is also referred to as ‘natural immunity. The adaptive or specific immune system mainly attacks the specific invaders. It consists of highly specialized cells called thymus-derived T lymphocyte cells and bone marrow-derived B lymphocyte cells. These cells are capable of recognizing different foreign antigens in a very precise way and have the capacity to generate immunological memory, which it allows recognizing the pathogens which have encountered before
The innate immune system is also known as the nonspecific immune system, which provides the first line of immunological defense against infection. The molecules and the receptors of the immune system provide a broad range of protection, so that it is also referred to as ‘natural immunity. The innate system is mainly composed of eosinophils, monocytes, macrophages, natural killer cells, tor-like receptors (TLRs), and a series of soluble mediators such as complement system.
Adaptive immunity can be divided into two types; humoral immunity and cellular immunity. Humoral immunity is mediated by antibody molecules secreted by B lymphocyte that can neutralize the pathogens outside the cells, and cellular immunity is mediated by T lymphocyte, which can eliminate infected cells and provide help to other immune responses.
The Immune Response In Action: 4 Phases To Immunity
(A)
Viruses invade the body through a varying portal of entry, they take over body cells in order to replicate. |
(B)
After recognizing the invading antigens, the helper "T" cells trigger the production of Killer "B" cells. |
(C)
Killer "T" and "B" cells destroy the infected body cells, this is done by marking/bonding the for destruction by macrophages. |
(D)
When the danger is over and the fight has been won, memory "T" and "B" are reserved and stationed on stand-by for future invasions. |
For more information on the immune system, please view the following videos and webpages by clicking the links provided below.
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