Ch 18 Immune System lecture Flashcards
What is immunity?
The ability to destroy pathogens and prevent infection.
What are the components of the immune system?
Lymphoid organs, lymphocytes, WBCs, and immune chemicals.
What is the function of the lymphatic system?
It returns lymph to circulation and helps filter pathogens.
Where are lymphocytes produced?
Red bone marrow.
What is the primary function of lymph nodes?
Filter pathogens and activate immune responses.
What is the spleen’s role in immunity?
It filters blood, destroys old RBCs, and stores platelets.
What is the function of the thymus?
It matures T cells for immune function.
What are antigens?
Chemical markers that identify cells as “self” or “foreign.”
What are natural killer (NK) cells?
Lymphocytes that destroy infected or cancerous cells using cytolysis.
What are the two main types of lymphocytes?
T cells and B cells.
Where do T cells mature?
In the thymus.
What is the main function of T cells?
Direct attack on infected or abnormal cells.
Where do B cells mature?
In the bone marrow.
What is the role of B cells?
They produce antibodies to fight infections.
What are antibodies?
Immunoglobulins (Ig) produced by plasma cells in response to antigens.
What are the five classes of immunoglobulins (Ig)?
IgG, IgA, IgM, IgE, IgD.
What is the function of IgG?
Provides long-term immunity; most abundant antibody.
Where is IgA found?
Mucosal secretions (tears, saliva, breast milk).
What is the function of IgM?
First antibody produced in an immune response.
Which antibody is involved in allergic reactions?
IgE.
What is the role of IgD?
Involved in B cell activation.
What is cell-mediated immunity?
An immune response that involves T cells attacking infected cells.
Which cells are involved in cell-mediated immunity?
Cytotoxic T cells, helper T cells, and memory T cells.
What is humoral immunity?
Immunity mediated by antibodies produced by B cells.