Lymphoid system
From IKE
Hypersensitivity Reaction
Components of the immune system
- White blood cells
- tissue lymphocytes, macrophages and mast cells
- human major histocompatibility complex
Origin of the immune cells
Sequence of maturation of immune cells
Final destination of immune cells
Know and understand the histology/components of normal lymph nodes, thymus gland, spleen, and mucosa associated lymphoid tissue
Know and understand the histological changes in the lymphoid organs upon stimulation by an antigen
Know the different types of the hypersensitivity reactions and understand why they are classified into four groups
Anaphylactic (Type I)
- aka immediate or allergic
- First exposure is usually silent
- Antigen activates T-H2 cells, which leads to the formation of IgE-secreting cells
- On the second exposure, the IgE binds explosively, and leads to a powerful reaction
- Reaction is immediate when the antigen is introduced
- Could be localized (hives, hay fever, asthma) or generalized (anaphylactic syndrome)
Cytotoxic (Type II)
- Usually a humoral reaction
- Caused by cytotoxic antibodies (IgG, IgM)
- Complement mediated cytotoxicity also plays a role
- this is best exemplified with wrong bloodtype transfrusions
Immune Complex (Type III)
Cell-mediated (Type IV)
- All cellular
- No immunoglobulins
