1-21 Cells and Tissues of the Immune Response (Intro to Immunology) Flashcards
What are the primary immune/lymphoid organs/tissues?
The organs/tissues where lymphocytes develop and mature.
- Bone marrow
- Thymus
What are the secondary immune/lymphoid organs/tissues?
The sites where mature lymphocytes become stimulated to respond to invading pathogens.
- Spleen
- Adenoids
- Tonsils
- Appendix
- Lymph nodes
- Peyer’s patches
What is the innate immune response?
The body’s inborn immune system response, whose recognition mechanisms are rapid, fixed, nonspecific, and constant during response.
Defenses include skin, stomach acidity, liquid flow in the urinary tract, phagocytes, the complement system, and receptors for bacterial markers.
What is the adapative immune response?
The body’s acquired immune system response, whose recognition mechanisms are slow, variable, and specific, and which improve during response.
Defenses include lymphocytes (B-cells and T-cells) and antibodies.
What is an opsonin?
Something that increases the phagocytosis of an object by binding to it and forming a high-affinity bridge. In Dr. Taffet’s words: “seasoning for the phagocytes.”
What is an antigen?
A molecule recognized by an antibody or T-cell receptor.
What is an antibody?
A serum protein that results from specific immune response and acts as a flexible specific adaptor between its target and effector.
Antibodies consist of heavy and light chains, as well as constant and variable regions. The constant regions end in the C termini; antigens bind to the variable regions, which end in the N termini. The Fc region, which consists of the base of the “Y” fork, can bind to Fc receptors on effector cells/proteins.
What is complement?
A serum protein that can either recognize certain micoorganisms directly or bind to and recognize bound antibody molecules. This process results in either lysis of the target cell or deposition of complement on the cell surface.
How do we define immune cells?
- Morphologically: stains, size and shape of cell, size and shape of nucleus, etc.
- Antigenically: clones of monoclonal antibodies can recognize subsets of immune cells. The rapid and confusing application, however, has led to the Cluster of Differentiation (CD) notation system.
What are some common CD designations?
- CD3: mature T-cells
- CD4: T-helper
- CD8: T-cytotoxic
What are neutrophils?
A phagocytic granulocyte that enters inflamed tissue and completes its short life cycle (12 hrs) there. Neutrophils are polymorphonuclear leukocytes (PMNs), as well as the most abundant leukocyte (60-70% of circulating white cells). They contain primary/azurophilic and secondary/specific granules, which contain the cell’s bactericidal and hydrolytic enzymes. Neutrophils are so called because they have both acidic and basic staining properties.
What are eosinophils?
Very short-lived (half-life = 30min) granulocytes and polymorphonuclear leukocytes (PMNs) that contain eosinophilic basic protein (EBP), which gives them acidic staining properties. Eosinophils defend against helminth worms and other intestinal parasites.
What is a basophil?
The rarest of the polymorphonuclear lymphocytes (PMNs). Very little is known about them, but they have acidic granules that give them basic staining properties.
What are monocytes?
Leukocytes that circulate through the blood. They have distinctive, indented nuclei and can become macrophages upon entering a cell.
What is a macrophage?
A large phagocyte that resides in tissues. Derived from monocytes, and distinguished by large, irregularly shaped cells with extensive cytoplasms and many vacuoles. Macrophage phagocytosis can be enhanced by antibodies and complement.
What are B-cells and T-cells?
Both are small lymphocytes and visually indistinguishable from one another.
- B-cells express immunogloblin, producing antibodies, and a single variable region (idiotype).
- T-cells are thymus-derived and perform “helper” functions; they regulate immune responses and the effector function of killing infected cells.
