Final answer:
There are five classes of immunoglobulins: IgM, IgD, IgG, IgA, and IgE. Each class has specific functions in the immune response.
Step-by-step explanation:
The five different classes of immunoglobulins found in humans are IgM, IgD, IgG, IgA, and IgE. Each class has specific functions in the immune response. For example, IgA is found in bodily fluids such as saliva and breast milk, while IgG is the most common class of antibody in the blood. IgM is involved in the early stages of an immune response, and IgE is associated with allergic reactions.