Immunology is the branch of biomedical science that deals with the study of the immune system, including its structure, functions, disorders, and interactions with pathogens, antigens, and other foreign substances.
The immune system is a complex network of organs, tissues, cells, and molecules that work together to defend the body against pathogens, such as bacteria, viruses, fungi, and parasites, as well as abnormal cells and foreign substances.
An antigen is any substance that can elicit an immune response in the body by binding to specific receptors on immune cells, called antibodies or T-cell receptors. Antigens can be foreign substances, such as pathogens or toxins, or they can be self-antigens produced by the body.
Antibodies, also known as immunoglobulins, are Y-shaped proteins produced by B cells of the immune system in response to the presence of specific antigens. Antibodies bind to antigens, marking them for destruction by other immune cells or molecules.
T cells, or T lymphocytes, are a type of white blood cell that plays a central role in cell-mediated immunity. T cells are responsible for recognizing and destroying infected or abnormal cells, as well as regulating the immune response.
B cells, or B lymphocytes, are white blood cells that play a key role in humoral immunity by producing antibodies in response to the presence of specific antigens. B cells also function as antigen-presenting cells, helping to activate T cells.
The immune response is the coordinated series of physiological processes initiated by the immune system to defend the body against infection, injury, or other threats. The immune response involves the recognition, targeting, and elimination of foreign substances or abnormal cells.
Inflammation is a localized protective response of the body to injury, infection, or irritation, characterized by redness, swelling, heat, and pain. Inflammation is an essential component of the immune response and helps to eliminate pathogens and repair damaged tissues.
Autoimmunity is a condition in which the immune system mistakenly attacks and damages the body’s own tissues, cells, and organs, leading to autoimmune diseases. Examples of autoimmune diseases include rheumatoid arthritis, lupus, and multiple sclerosis.
Immunodeficiency is a condition in which the immune system is impaired or weakened, making individuals more susceptible to infections and diseases. Immunodeficiency disorders can be inherited or acquired and may affect one or more components of the immune system.