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Spicer Ex2 Review
Review Questions for Exam 2 Intro to Pathology, Spicer, Bastyr
Question | Answer |
---|---|
Pluripotent stem cells differentiate into WHAT 3 types of formed elements circulating in the plasma of the vascular system? | - Erythrocytes (RBCs) - Leukocytes (WBCs) - Thrombocytes (Platelets) |
DEFINE LEUKOCYTES: | The leukocytes are involved in immune system functions. |
Define PLURIPOTENT STEM CELL: | Stem cell that can divide into a few other types of cells |
Pluripotent cells divide into what types of cells in the immune system? | Myeloid stem cell Lymphoid stem cell |
Myeloid Stem Cells become: | RBC Platelet Monocyte Granulocyte |
Lymphoid stem cells become? | NK cell B lymphocyte T lymphocyte |
What are the types of Granulocytes? | Neutrophil Eosinophil Basophil |
Monocytes become what type of cell in tissue? | Macrophage |
B Lymphocytes become what type of cell in tissue? | Plasma Cell |
Functions of RBC: | ferrying oxygen & carbon dioxide between lungs and tissues |
Functions of Platelet: | clotting; inflammation |
Functions of Monocyte: | transforms into macrophages: fixed –vs- wandering, to perform phagocytosis. |
Functions of Neutrophil: | phagocytosis of bacteria |
Functions of Eosinophil: | combats effects of histamine during allergic reactions; attacks parasites |
Functions of Basophil: | releases heparin, histamine, & serotonin to intensify inflammation |
Agranulocytes: | Functions of Natural Killer Cell: attacks infectious microbes and tumor cells; primary defense. p146 |
Functions of B Cell: | developed in bone marrow; becomes plasma cell and secretes antibodies against bacteria |
Functions of T Cell: | developed in thymus; attacks viruses, fungi, transplanted cells, cancer cells, some bacteria in highly targeted ways |
Define: ANTIGEN (Ag): | Any molecule capable of stimulating an immune reaction (most are proteins); don’t have to be “foreign”. Ex: measles virus Ex: transplanted tissue |
Define: HAPTENS: | small non-protein molecules that combine with a self-protein and stimulate an immune reaction. Ex: poison ivy |
Define: CYTOKINES: | small soluble molecules involved in inflammation; aim is to neutralize or destroy the target. |
Define: ANTIBODIES (Abs): | custom made proteins designed to attack other proteins; are released into bloodstream by plasma (B) cells. |
Define: CYTOTOXIC T CELL: | these attack cells have been stimulated by Ag. |
Define: AUTOIMMUNE: | immune system attacks self proteins, rather than non-self (foreign) proteins. |
Define: MACROPHAGES: | digest, prepare, and present foreign Ags to T cells |
What are some various Types of immunity: | Skin Sclera Respiratory tract Gastrointestinal tract Genitourinary tract Body fluids Cellular defenses Molecular defenses |
What are the 2 distinct but inter-related components of Immunity? | Humoral and Cellular |
Define HUMORAL IMMUNITY: | soluble antibody proteins are produced by B cells (plasma cells). These customized proteins can directly neutralize extracellular microbes, or can activate complement and effector cells (neutrophils/PMNs & macrophages) to kill microbes. |
Define CELLULAR IMMUNITY: | T cells directly lyse targets (cytotoxic T cells) or induce antimicrobial responses from other cells via cytokine production (helper T cells). T cells cannot “see” antigen unless it has been processed & presented by other cells. |
How are NK cells different from other cellular immunity? | NK cells act as a first line of defense against invaders, needing no activation. |
Where are B Cells educated? | “B” indicates bone-marrow educated. |
Describe B Cells: | B cells make up ~10-20% of circulating peripheral lymphocytes, and can be found in bone marrow, lymph nodes, spleen, tonsils, GI tract, bronchial tract. |
What do stimulated B Cells become? | Stimulated B cells become plasma cells that secrete immunoglobulins (mediators of humoral immunity) after encountering antigens. |
What are the classes of immunoglobulins? | There are 5 classes of immunoglobulins that form antibodies: Ig: G, M, D, A, E, (Ig stands for immunoglobulin) |
What are the most prevalent antibodies? | G, M, and A represent over 95% of all circulating antibodies. Effective against bacteria; not so effective against viruses or other microbes. |
Describe IgM: | Big heavy, first to be produced |
Describe IgG: | long term protein |
Describe IgA: | mucosal "immune paint" |
Describe IgE: | parasites, allergies, (w mast cells) |
Describe IgD: | on surface of B cells. |
Describe Memory B cells: | instead of producing Ab, they hang out as a trigger for a fast response the next time the Ag is encountered; this forms the basis for vaccinations. B cell function is critically dependent on T cells (to be discussed). |
Where are T Cells educated? | “T” indicates the organ these cells mature in: thymus. |
functions of T Cells: | T cells do 2 jobs: 1) induce humoral immunity (via B cells) AND 2) carry out cellular immunity. |
What is the percentage of T Cells in the blood? | T cells are ~ 80% of the lymphocytes in circulating blood; are the majority of lymphocytes in the spleen and lymph nodes. |
How do T cells recognize antigens? | Each T cell has a unique T Cell Receptor (TCR), a protein arrangement on its plasma membrane that will recognize one particular processed peptide fragment (antigen). |
How do T cells identify pathogens? | The billions of potential antigens/peptides in our world can be recognized by T cells because of rearrangement of genes (during development) that gives each T cell a unique TCR. |
What are basic functions of T Cells? | defend against viruses, fungi involved in tissue transplant rejections |
What are the Types of T cells? | helper, suppressor, memory, and cytotoxic – name indicates their jobs. |
How does "memory" differ between T and B cells? | T cells perform “delayed” immunity, a day or so, compared with B cells which are immediate. |
Describe Macrophages: | Macrophages process and present antigen to CD4+ helper T cells. Secrete cytokines influencing T-cell and B-cell, endothelium, and fibroblasts. Phagocytosis to kill microbes coated by antibody and/or complement, also important in humoral immunity. |
Describe Natural Killer (NK) Cells: | They are 10-15% of circulating blood lymphocytes. They contain abundant granules & can lyse tumor cells, virally infected cells, and some normal cells without prior sensitization (thus they represent the 1st line of defense). |
Do NK cells destroy "self" cells? | NK cells will not lyse healthy nucleated cells, but if a cell becomes “weird” (viral infection, tumor transformation, etc.), the NK cell will attack. |
How do NK cells destroy antigens? | NK cells secrete cytokines; gamma-interferon (interferes with viral replication) is especially noteworthy. |