-
B cells (B lymphocytes)
- Produces antibodies that combat foreign molecules known as antigens
- B cells are lymphocytes that are created and mature in red bone marrow
- Recognize antigens and make antibodies
- Named for bursa of Fabricius in birds
- Humoral immunity involves B lymphocytes, more commonly known as B cells, which remove viruses, bacteria, and toxins form body tissue fluids and blood by recognizing antigens and making antibodies against them
- The recognition of different antigens depends on B cell receptors (BCR) for antigens that coat the surface of the B cell
- In humans, lymphocytes are initially produced in the fetal liver, but by about the third months of life the site of the creation and maturation or schooling of the B cells becomes the red bone marrow
- Phagocytosis - looking for things to eat. Special receptor, B cell receptor (BCR); do not get inside of cells
-
T cells (T lymphocytes)
- Cellular immunity (Cell-mediated immunity)
- T cell do not bind to antigens directly, but recognize antigenic peptides after they have been processed by phgocytic cells such as macrophages
- T cells and B cells both develop from stem cells in the red bone marrow, however T cell mature under the influence of the Thymus
- Both T cell and B cell are found primarily in blood and lymphoid organs
- The responses of cellular immunity center on attacking antigens that make their ways inside cells, whereas humoral immunity responses are directed at antigens the are extracellular (such as in blood or other body fluids)
- Cellular immunity is generally best at fighting viruses that have infected cell
- Te cells respond to antigens by means of receptors on their surface - T cell receptors (TCR) contact with an antigen complementary to a TCR and cause certain types of T cells to proliferate and secrete cytokines rather than antibodies
-
What are types of adaptive immunity?
- Natural acquired active immunity - result from infection; naturally induced antibodies
- Naturally acquired passive immunity - transplacental or via colostrum; Antibodies pass from mother to fetus via placenta or to infant via the mother's milk
- Artificially acquired active immunity - injection or vaccination (immunization); Antigens are introduced in vaccination. Body produces antibodies and specialized lymphocytes
- Artificially acquired passive immunity - injected of antibodies;Performed antibodies in immune serum are introduced by injections
|
|
