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A non-specific immune cell is an immune cell (such as a macrophage, neutrophil, or dendritic cell) that responds to many antigens, not just one antigen. Non-specific immune cells function in the first line of defense against infection or injury.
Some products of the coagulation system can contribute to non-specific defenses via their ability to increase vascular permeability and act as chemotactic agents for phagocytic cells. In addition, some of the products of the coagulation system are directly antimicrobial .
Innate immune defenses are non-specific, meaning these systems respond to pathogens in a generic way. [19] This system does not confer long-lasting immunity against a pathogen. The innate immune system is the dominant system of host defense in most organisms, [2] and the only one in plants. [20]
Humoral immunity is the aspect of immunity that is mediated by macromolecules – including secreted antibodies, complement proteins, and certain antimicrobial peptides – located in extracellular fluids.
A scanning electron microscope image of a single human lymphocyte. The adaptive immune system, AIS, also known as the acquired immune system, or specific immune system is a subsystem of the immune system that is composed of specialized cells, organs, and processes that eliminate pathogens specifically.
Besides phagocytosis, they play a critical role in nonspecific defense (innate immunity) and also help initiate specific defense mechanisms (adaptive immunity) by recruiting other immune cells such as lymphocytes. For example, they are important as antigen presenters to T cells.
Animals, including humans, have many natural defences against viruses. Some are non-specific and protect against many viruses regardless of the type. This innate immunity is not improved by repeated exposure to viruses and does not retain a "memory" of the infection. The skin of animals, particularly its surface, which is made from dead cells ...
An immune response is a physiological reaction which occurs within an organism in the context of inflammation for the purpose of defending against exogenous factors. These include a wide variety of different toxins, viruses, intra- and extracellular bacteria, protozoa, helminths, and fungi which could cause serious problems to the health of the host organism if not cleared from the body.