Your body is like a castle under siege.discuss (biology) - Essay Example

All these cells possess the inherent ability to distinguish between self and non-self antigens while they develop as it is the key requirement in any defense mechanism. Once an antigen or a foreign body is detected these cells put forth a defense mechanism which protects the individual from the invading pathogens and helps to eliminate them. This defense could either be antigen dependent or independent. When immune cells attack any incoming antigen without being specific it is referred to as innate or non-specific immune response.

Anatomical barriers such as skin and various body secretions and normal flora present within the body act as the immediate and first line of non-specific defense against the invading pathogens. When the foreign bodies escape these barriers the humoral components of the innate defense mechanism which includes the complement system, coagulation system that help to recruit phagocytic cells and secretion of substances such as interferon’s, lysozyme and interleukins play a vital role in eliminating the foreign substances.

The cellular components involved in the innate defense mechanism include neutrophils and macrophages which act through phagocytosis, natural killer cells and eosinophils (Mayer, 2009). In contrast to the innate defense, the specific, acquired or adaptive defense mechanisms are antigen dependent. In the specific response a time lag exists between exposure to the antigen and the immune response generated as the acquired immune response is not inherent from birth, instead it is specific and unique to every antigen encountered and a memory of that response is also created by which subsequent exposure to that antigen will generate a similar and a more effective response (Mayer, 2009; Delves, 2008).

The lymphocytes present in the blood are the major cells involved in the specific immune response and the two major types of cells, the B and T lymphocytes all of which originate in the