The complex network of cells, tissues, organs, and molecules that work together to defend the body against harmful pathogens such as bacteria, viruses, fungi, and parasites, as well as aberrant cells like cancer cells.
Any organism or substance capable of causing disease, including viruses, bacteria, fungi, and parasites.
A molecule or substance recognized by the immune system as foreign, triggering an immune response. Antigens can be present on the surface of pathogens or on abnormal cells such as cancer cells.
Also known as immunoglobulin, antibodies are proteins produced by the immune system in response to the presence of antigens. They recognize and bind to specific antigens, marking them for destruction by other immune cells.
A type of white blood cell produced in the thymus gland that plays a central role in cell-mediated immunity. T-cells can directly kill infected or abnormal cells and help coordinate the overall immune response.
Another type of white blood cell involved in adaptive immunity. B-cells produce antibodies in response to specific antigens and play a crucial role in humoral immunity.
The coordinated series of actions taken by the immune system to eliminate pathogens or foreign substances from the body. This response can involve both innate (non-specific) and adaptive (specific) mechanisms.
A protective response by the immune system to tissue injury, infection, or irritation. It involves the recruitment of immune cells to the affected area to eliminate pathogens and promote tissue repair.
A decrease in the effectiveness or activity of the immune system, which can result from various factors such as medications, underlying medical conditions, or environmental exposures. Immune suppression can increase susceptibility to infections and other diseases.
A condition in which the immune system mistakenly attacks the body’s own tissues and organs, leading to inflammation and damage. Examples include rheumatoid arthritis, lupus, and type 1 diabetes.