Exam 1 (Lecture 1) - Immune System Overview Flashcards
Immune System Overview
List the 2 major arms of the immune system.
1) Innate immunity
2) Adaptive immunity
Describe 3 basic differences between innate and adaptive immunity.
1) Innate is an immediate response; adaptive is slower.
2) Innate is not antigen-specific; adaptive is antigen-specific.
3) Innate does not have memory; adaptive does have memory.
Describe how barriers contribute to defense against pathogens and give one or two examples.
1) Barriers to infection = innate protection
2) Intact skin and mucous membranes = epithelial barriers
Examples: stomach acid, mucous, antimicrobial peptides
List 3 soluble components and 3 cellular groups of the innate (broad) defense system.
1) Soluble (molecules):
- complement system
- defensins (poke holes in
membranes
- cytokines (proinflammatory
cytokines
2) Cells:
- neutrophils
- macrophages
- eosinophils/basophils
Describe the two major components of the adaptive immune system.
1) Cell-mediated: (T cells; T-helper cells (CD4+) and cytotoxic T-cells (CD8+)
2) Humoral (soluble): contains antibodies (made by plasma cells); plasma cells differentiate from B-cells.
Explain where antibodies come from, including the name of the cell that secretes antibody, and list the different classes (isotypes) of antibody.
Antibodies are made and secreted by plasma cells (differentiated B-cells); IgG, IgA, IgM, IgE.
List the different types of T lymphocytes (T cells) and describe how they contribute to a cell-mediated immune response.
1) T-Helper (CD4+) = secrete cytokines (proteins); various T-Helpers secrete various cytokines; regulate innate and adaptive immune mechanisms.
2) Cytotoxic T (CD8+) = attach to and kill cells displaying foreign proteins.
3) Gamma-delta T cells = important for protection on mucosal surfaces.
Briefly define and describe immunologic memory and immunologic tolerance.
1) Memory = more cells recognize the specific antigen (or already have the antibody)
2) Tolerance = our immune system does not attack self-cells (when functioning properly)
What is an antigen?
Any substance that can stimulate the production of antibodies and combine specifically with them. B and T cell receptors can bind to this.
What is an immunogen?
Any substance or cell introduced into the body in order to generate and immune response; binds to B and T cell receptors to induce immune response
What is an antibody?
Y-shaped protein molecules produced by B cells as a primary immune defense; each molecule and its clone have a unique binding site that can combine with complementary binding site of a foreign antigen thereby disabling the antigen and signaling other immune defenses.
What is a cytokine?
A type of small protein secreted by certain cells that help regulate the body’s immune response to inflammation and disease.
What is complement?
A complex system of more than 30 proteins that act in concert to help eliminate infectious microbes; causes lysis of foreign and infected cells, phagocytosis of foreign particles and cell debris and inflammation of surrounding tissue.
