Question

describe what is involved in the adaptive immune system?

Answer 1

Adaptive immune system is one of the defence mechanism other than innate immune system of our body against pathogens. It is also known as acquired immune system and it  produce pathogen specific immune response by the B lymphocytes and the T lymphocytes. These B and T lymphocytes are derived from hematopoietic stem cells from the bone marrow. The T lymphocytes produce cytokines, CD4+ T cells and CD8+ T cells and they are involved in cell mediated immunity by killing the pathogens attacking the cells. The B lymphocytes produce antibodies and they are involved in humoral mediated immunity by killing the pathogens entering the blood stream. During a primary attack of pathogen, the T cells and the B cells are produce to fight against the pathogen. Their actions will be pathogen specific. The dendritic cells present the antigen to the T cells and initiate pathogen specific immune response. Also the B cells produce a specific antibodies to a specific antigen by analyzing the genetic information of the antigen. This primary attack will produce memory B cells. So during their secondary attack, the memory B cells which is already present in the body will initiate a faster immune respose by detecting the genetic information of the pathogen. This secondary immune action normally doesn't produce any symptoms in individuals. For example consider the disease chickenpox caused by varicella zoster virus. If a person had chickenpox in their childhood, it is less likely to get reinfected with varicella zoster virus later in their life time. So that means, the adaptive immunty works as a defensive mechanism, by adapting to the changes bought by the virus or any other pathogen during their primary attack.