Final answer:
The three types of hypersensitivity are immediate hypersensitivity, delayed hypersensitivity, and autoimmunity.
Step-by-step explanation:
The three types of hypersensitivity are:
- Immediate hypersensitivity: This type of hypersensitivity involves an immune reaction that occurs within minutes of exposure to a harmless antigen. It is mediated by antibodies, leading to symptoms such as allergies.
- Delayed hypersensitivity: Delayed hypersensitivity is a cell-mediated immune response that takes one to two days to develop. It is initiated by T cells and can manifest as local tissue lesions or contact dermatitis.
- Autoimmunity: Autoimmunity is a type of hypersensitivity where the immune system mistakenly attacks self antigens, causing autoimmune diseases.