The human immune system is a complex combination of cells and mechanisms of their interactions that protect the body from infections and fight them. Thus, there are two main types of immunity that act at different phases of microbes and bacteria penetration, namely innate immunity and adaptive immunity. These immunities have many differences in chemical and physical factors and work; however, their interaction creates the most effective protection process.
The first difference in innate and adaptive immunities is that innate immunity is present in the body from birth, while adaptive immunity appears after exposure to a foreign substance. Innate immunity is also called non-specific, since it fights all microbes entering the body, while adaptive immunity resists only specific infections (Cooper & Gosnell, 2018). A feature of adaptive immunity is also that it has a memory; therefore, when bacteria and microbes reoccur, it recognizes them and prevents disease development. The cells that fight infections are called lymphocytes, and their secreted products that recognize foreign substances, or antigens, are called antibodies (Cooper & Gosnell, 2018). For this reason, scientists distinguish four types of adaptive immunity, such naturally acquired active or passive immunity and artificially acquired active or passive immunity (Cooper & Gosnell, 2018). These types differ in the natural or artificial source of the provoking the production of antibodies, and the external or internal sources of obtaining these antibodies. However, the two basic types of adaptive immunity are humoral immunity, the primary defense cells of which are B-cells, and cell-mediated immunity that uses T-cells for defense.
At the same time, the innate immune system is composed of phagocytic leukocytes, natural killer cells, dendritic cells, plasma proteins, and chemical and physical barriers. Such barriers are skin, mucous membranes, chemicals on epithelia, temperature, and pH (Cooper & Gosnell, 2018). The adaptive immune system barriers are spleen, mucosal-associated lymphoid tissue, and lymph nodes (Cooper & Gosnell, 2018). Thus, innate immunity is the first obstacle to the penetration of infections, since if microbes penetrate the barriers, then phagocytes create a second line of defense entering the blood. This process manifests in inflammation and fever since high temperature is also a defense mechanism against foreign microbes and bacteria. Adaptive immunity has a more efficient and faster response to infections, but only if this type of antigens is already known to the body. Otherwise, the body takes time to develop antibodies and fight foreign bacteria or viruses.
Reference
Cooper, K., & Gosnell, K. (2018). Foundations and adult health nursing e-book (8th ed.). Elsevier Health Sciences.