Immune System
Immunity is resistance to disease resulting from the presence of foreign substances or _______ in the body
Antigens
What signifies that a lymphocyte has become immunocompetent?
Appearance of antigen-specific receptors on membrane of lymphocytes
The major actors in the immune response are two lymphocyte populations, the _____ and the _____.
B Cells & T Cells
Produces antibodies that are released to body fluids
B cell
Progeny are plasma cells
B cell
What triggers the process of clonal selection in a T or B cell?
Binding to "its" antigen
Because pathogens are likely to use both ____ and ______ as a means of getting around the body, ______and other lymphatic tissues are in an excellent position to detect their presence
Blood, Lymph, Lymph Nodes
When living cells provide the protection, the immunity is called _______
Cellular immunity
During what period of life does immunocompetence develop?
Fetal life
When this resistance is provided by antibodies released to body fluids, the immunity is called _____
Humoral immunity
What determines which antigen a particular T or B cell will be able recognize?
Its genes
Phagocytic cells that act as accessory cells in the immune response are the _____
Macrophages
Accounts for most of the lymphocytes in the circulation
T cell
Is responsible for directly attacking foreign cells or virus-infected cell
T cell
Originates in bone marrow from stem cells called hemocytoblasts
T cell
Progeny include suppressors, helpers, and killers
T cell
Bears a cell-surface receptor capable of recognizing a specific antigen
T cell & B cell
Forms clones upon stimulation
T cell & B cell
Progeny include memory cells
T cell & B cell
Small molecules are not usually antigenic, but when they bind to self cell surface proteins they may act as ______, and then the complex is recognized as foreign, or ______
haptens, nonself
Antigens are substances capable of mobilizing the
immune system
Transferring antibodies from one person to another
passive immunity
Of all the foreign molecules that act as complete antigens _______ are the most potent
proteins
Vaccination with antigen (lasts for years)
active immunity