This article examines the biological foundations of the immune system, its structural and functional characteristics, and its role in protecting the body against various diseases. The immune system is a complex defense mechanism of the human body that forms specific cellular and humoral responses against microorganisms, viruses, and toxins entering from the external environment. The article scientifically analyzes innate (natural) and adaptive (specific) types of immunity, their interrelationship, and the stages of the immune response. In addition, immune system disorders such as immunodeficiency, autoimmune diseases, and allergic reactions are discussed. The results of the study substantiate the crucial role of a healthy immune system in maintaining human health and resistance to diseases.

immune system, immunity, lymphocytes, antibodies, defense mechanisms, autoimmune diseases.

Abbas, A. K., Lichtman, A. H., & Pillai, S. (2023). Cellular and Molecular Immunology. 11th ed. Elsevier.

Roitt, I. M., Brostoff, J., & Male, D. K. (2021). Immunology. 9th ed. Elsevier Health Sciences.

Alberts, B. et al. (2022). Molecular Biology of the Cell. 7th ed. Garland Science.

Umarov, R. T., & Karimova, N. A. (2020). Biological Systems and Their Defense Mechanisms. Tashkent.

Qodirov, M. A. (2021). Fundamentals of Human Physiology and Immunology. Tashkent.

World Health Organization (2023). Immunity, Vaccines and the Human Immune System.

National Institutes of Health (2024). Human Immunity and Disease Resistance: Current Research Directions.

Omonov, B. S., & Rakhimova, D. I. (2019). The Importance of Immunology in Medicine.