Explanation of How Our Immune System Works

A modern medical science has developed significantly, yet numerous microorganisms in our environment can cause serious diseases. These include bacteria, fungi, and parasites that can easily penetrate our bodies and trigger infections. The body’s defense against these pathogens is extremely important, as the immune system’s role is to prevent infections and maintain the integrity of the body.

The Role of Non-Specific Immunity

Non-specific immunity forms the first line of defense against pathogens and is fundamentally based on physical and chemical barriers. The skin, as the largest organ of the body, prevents the entry of pathogens, while mucous membranes and the secretions they produce help fend off infections. Sebum, saliva, and gastric juice are all substances that prevent the proliferation of pathogens.

If pathogens get past this external defense system, internal defense mechanisms come into play. These include phagocytes, which can engulf pathogens, as well as natural killer cells that play a crucial role in eliminating infected cells. Inflammatory responses and fever also aid the body’s defense, as they make it more difficult for pathogens to multiply and enhance the effectiveness of defensive substances.

Therefore, non-specific immunity plays a fundamental role in preventing infections, yet it cannot accurately identify pathogens. This is why specific immunity is necessary, which provides targeted and effective responses to various infections.

Specific Immunity: Targeted Defense

Specific immunity functions as a complement to innate defense mechanisms and is capable of identifying and specifically attacking different pathogens. During specific defense, the body “remembers” the antigens, which are substances found on the surface of pathogens, and is able to respond more quickly and effectively upon subsequent encounters.

There are two main types of specific immune responses. The first is the cell-mediated immune response, in which T cells actively participate in the elimination of pathogens. These cells can directly engulf invading substances, effectively combating viruses and bacteria as well as cancer cells and foreign tissues.

The second type is the antibody-mediated immune response, during which B cells differentiate into plasma cells and produce antibodies. Antibodies specifically bind to pathogens, neutralizing their effects. This form of defense is particularly effective against circulating antigens in the blood, such as viruses and bacteria.

Specific immunity thus enables the body to remember pathogens that have already attacked, allowing for a rapid response to future infections, significantly increasing the effectiveness of defense.

Transplantation and Transfusion: Immunological Challenges

The immune system not only protects the body against pathogens but also actively defends against tissues from other individuals. During organ transplants, if the donor and recipient tissues do not match properly, the body may reject the foreign organ. Therefore, for the success of organ transplantation, it is important that the tissue types of the donor and recipient closely resemble each other.

Blood transfusions can also pose serious immunological challenges. If someone receives blood from a foreign blood group, the body may react by producing antibodies, leading to severe complications. For example, a person with blood type A receiving blood type B can trigger a strong immune response against B antigens. To avoid such reactions, accurate identification of blood groups and the selection of appropriate blood products are essential.

These examples clearly demonstrate that the role of the immune system is not only crucial in defending against infections but also in reacting to foreign substances. The continuous expansion of immunological knowledge enables safer treatments and interventions, which is essential for the advancement of modern medicine.