HS 350 - Exam 3 Questions With Correct Answers

Cells adapt by changing their: - Answer 1. size (hypertrophy or atrophy) 2. number (hyperplasia) 3. type (metaplasia) Relationship between hypertrophy and hyperplasia - Answer Hypertrophy occurs in cell types where hyperplasia, the generation of more cells, is uncommon (eg. muscle cells) Why might metaplasia occur? - Answer it occurs in response to chronic irritation and inflammation; one cell type replaces another Define dysplasia - Answer deranged cell growth resulting in varying sizes, shapes, and disorganization; occurs in chronically inflamed tissues; precursor to cancer apoptosis - Answer programmed, orderly, well-controlled cell death necrosis - Answer premature cell death, caused by a toxin, enzyme digestion, or pathogen, usually detrimental pyroptosis - Answer cell death that releases some bad things but may stimulate immune response What is inflammation? - Answer a cellular and vascular response to injury; blood cells show increased flow, capillaries become warmer, interstitial cells & mast cells vasodilators - Answer histamine, kinines, leukotrines, Nitric Oxide acute inflammation - Answer relatively uniform response to acute injury characterized by accumulation of fluid, plasma proteins, and granulocytic leukotrines Outcomes of acute inflammation - Answer resolution, scarring, abscess, or it becomes chronic inflammation causes of acute inflammation - Answer physical and chemical injury, some forms of immune injury or overreaction causes of chronic inflammation - Answer persistent infectious agents, autoimmune diseases, persistent exposure outcomes of chronic inflammation - Answer 1. resolve and cause fibrosis 2. continuation Systemic effects of inflammation - Answer lymphangitis, lymphadenitis, lymphadenopathy; fever/fatigue; decreased appetite, decreased grooming; acute-phase protein production by liver; bone marrow increases hematopoeisis; increased brain ACTH production, makes corticosteroids that suppress immunity 3 types of cells that replace injured cells - Answer 1. labile cells 2. stable cells 3. permanent cells Labile cells - Answer undergo continuous, rapid diffusion under normal circumstances; can be easily repaired Stable cells - Answer have a high regenerative capacity, but are activated by injury or stress permanent cells - Answer they are incapable of regeneration and heal via scarring only What are two types of tissues that make up cellular scaffolding? - Answer 1. Basement membrane 2. Extracellular matrix Basement membrane - Answer thin membrane under all epithelium, sometimes needs to be repaired Extracellular matrix - Answer collagen and elastic fibers and polysaccharides, supports cell re-growth Why might abnormal wound healing occur? - Answer many factors: poor nutrition, infection, steroid drugs, poor blood supply, foreign body, mechanical stress/factors Innate immunity - Answer 1st and 2nd lines of defense Acquired/specific immunity - Answer 3rd line of defense; vast capacity for foreign recognition, immunologic "memory," recognizes self from non-self 1st line of defense - Answer physical barriers to infection: skin, mucus membranes, microbial micro biome 2nd line of defense - Answer innate (non-specific) defense: phagocytes, macrophages, inflammation, fever, antimicrobial substances 3rd line of defense - Answer T and B lymphocytes Where is the immune system anatomically? - Answer Everywhere! 1. Tonsil and adenoids 2. Thymus (location of T-cell maturation) 3. Lymph noeds and vessels 4. Spleen 5. Peyer's patches 6. Appendix 7. Bone marrow Antigen - Answer an organism, molecule, or part of molecule that is recognized by the immune system epitope - Answer smallest part of the antigen that is "seen" by T or B cell receptors Physical factors of 1st line of defense - Answer -skin and epidermis are tightly packed cells with keratin, a protective protein -mucus membranes trap microbe and mucociliary escalator lines respiratory tract, brings pathogen up -"flushing" action and chemicals in tears and saliva Chemical factors of the first line of defense - Answer -fungistatic fatty acid in sebum -low pH (1.2-3) of gastric juice -low pH (3-5) of skin and vaginal secretions -lysosyme in perspiration, tears, etc. -microbial antagonism and competitive exclusion 2nd line of defense consists of - Answer 1. Immune defenses at the sit elf entry: cells and chemicals 2. Stop the pathogen before it spreads by recognizing that it's a pathogen 3. Recruit cells to the site of the pathogen and injury via inflammation Formed elements in the blood - Answer -RBCs or erythrocytes=transport O2, CO2 -Platelets -Neutrophils=first response -Basophils=allergies, histamine -Eosinophils=worms -Monocytes in blood, mature into macrophages in tissues -Dendritic cells=key immune cells of system Dendritic cells' function - Answer bridge between innate and adaptive immune systems by antigen-presenting, constantly test extracellular environment, carry out phagocytosis; works between the dendrititc cells of the lymphoid progenitor and the monocyte/macrophages of the myeloid progenitor lymphoid progenitor - Answer 1. B lymphocytes, which make antibodies and hare highly specific 2. T lymphocytes, which have cytotoxic properties and are also a part of the 3rd line of defense 3. natural killer (NK) cells are nonspecific 4. Dendritic cell myeloid progenitor - Answer 1. RBCs and platelets 2. Granulocyte macrophage progenitor --basophil & mast cell --eosinophil --neutrophil --monocyte and macrophage NK cells - Answer innate immune response killing viruses T cells funct. - Answer 1. orchestrate immunity 2. kill stuff B cells funct. - Answer produce antibody Differential WBC count in humans - Answer 1. Neutrophils: 60-70% 2. Basophils: 0.5-1% 3. Monocytes: 3-8% 4. Lymphocytes: 20-25% Immunes cells in tissue - Answer mast cell-->activation; macrophage-->role in phagocytosis, destroys many types of pathogens, immunomodulatory, other functions. 2nd line of defense, nonspecific immunity, but... - Answer ...actually somewhat specific because it's able to identify the difference between self as a pattern that distinguished virus vs. bacteria microbial patterns vs. self (via PAMPs) PAMPs - Answer Pathogen-Associated Molecular Patterns PRRs - Answer Pattern Recognition Receptors What types of leukocytes act on parasites? - Answer eosinophils, basophils, and mast cells What types of leukocytes act on bacteria? - Answer monocytes, macrophages, and neutrophils What types of leukocytes act on viruses? - Answer pDC/IPC, NK, dendritic cells, chemical interferons TLRs - Answer toll-like receptors, one type of PRR that helps a cell distinguish what is a pathogen and what is not by attaching to its PAMP Functions of innate cells - Answer phagocytosis, antimicrobial chemical release, direct killing interferon & how it works - Answer interferes with viral replication; potent chemical; the viral infected cell makes an interferon and sends it to the neighboring cell to warn it; makes antiviral proteins that prevent further infection complement system with complement cascade - Answer the cascade is a series of proteins that can be triggered in different ways; helps in anti-bacterial defense and inflammation; carries out phagocytosis or other things, killing foreign invaders diapedesis - Answer how immune cells leave the blood and get into the tissues: slow down, stick to endothelial cell layer, and squeeze through it chemokines - Answer attract immune cells to the site of injury by directing cell traffic; eg. CXC8, CLL Timing of acute inflammatory response - Answer Day 1: Vasodilation Day 1/2: Edema Day 2: neutrophils Day 3: Monocytes and Macrophages cytokines or interleukins - Answer proliferation, activation, and inhibition Steps that a dendritic cell takes to activate adaptive immunity - Answer 1. Presents an antigen (Uses pathogen-receptor targets OR phagocytosis to do so) 2. Phagolysosome chops up antigen into small pieces 3. Presents the small pieces to the adaptive immune system, and an immature T or B cell responds, then matures to respond even more fully in defense T-Helper Cells (CD4+) - Answer secrete MHC II proteins, also called HLA in human (must match up for donor organs to be received and not rejected), help distinguish self from non-self Cytotoxic T Cells (CD8+) - Answer kills; these are the MHCI proteins on the cell's surface 2 pathways of antigen presentation/cellular recognition - Answer 1. exogenous antigens 2. endogenous antigens Exogenous antigens - Answer detect pathogens outside cells, eg. bacteria or worms; cell uptakes, lyses, presents it on surface using MHC II, and CD4 T cell can sense it (helper T cell); enhances macrophage in effort to kill by making more cytokines, which activate B-cells Endogenous antigens - Answer detect pathogens inside cells, eg. viruses; are presented to cytotoxic T-cells, have MHC I molecules on surface; T cells are highly specialized to respond only to, say, the flu or other types of invaders B cells can be both antigen-_______________ and antigen-______________ cells. - Answer receiving; presenting Different epitopes the B and T cells can recognize - Answer 1. B cell: recognizes on surface of microbe 2. T cell: often internal pert of microbe that must be "processed" first T and B cells may interact with different epitopes and yet have specificity for the same antigen (interact with different regions of the antigen) B cell that binds to antigen - Answer needs to fit very specifically with the receptor site...works like a hormone receptor...binding then initiates activation of the B cell; it secretes antibodies for the specific antigen B cell recognizes, and then must respond. How? - Answer making antibodies, which can neutralize the microbe, and diff antibodies work on different pathways