micro bio exam 3

• Q: What are the symptoms of inflammation?

• A: Redness, heat, swelling, pain, and loss of function.

• Q: In inflammation, what do histamine, prostaglandins, and kinins do?

• A: Histamine causes vasodilation and permeability. Prostaglandins intensify inflammation. Kinins attract phagocytes.

• Q: What are CD4 and CD8 cells and what are other names for them?

• A: CD4 = Helper T cells, CD8 = Cytotoxic T cells.

• Q: What do helper T cells do?

• A: Activate B cells, other T cells, and macrophages; coordinate immune response.

• Q: What is immunogenicity?

• A: The ability of a substance to provoke an immune response.

• Q: What is the structure of an antibody?

• A: Y-shaped with two heavy and two light chains, variable and constant regions.

• Q: What are the parts of the antibody?

• A: Fab (antigen-binding fragment), Fc (constant region), heavy and light chains.

• Q: What are the 5 different types of antibodies and their functions?

• A: IgG: long-term immunity; IgA: mucosal defense; IgM: first responder; IgE: allergy/parasites; IgD: B cell activation.

• Q: What are the percentages of antibodies in your body?

• A: IgG ~75%, IgA ~15%, IgM ~5-10%, IgE & IgD <1%.

• Q: Where do you find the different antibodies?

• A: IgG: blood; IgA: secretions (tears, saliva); IgM: blood/lymph; IgE: skin/mucosa; IgD: B cells.

• Q: What are the different types of T cells and what do they do?

• A: Helper T: activate immune cells; Cytotoxic T: kill infected cells; Regulatory T: suppress immunity; Memory T: provide memory.

• Q: How do cytotoxic T cells kill?

• A: Release perforin and granzymes causing apoptosis in target cells.

• Q: What do natural killer cells, phagosome, neutrophil, monocyte, eosinophil, basophil do?

• A: NK: kill infected cells; Phagosome: vesicle for digestion; Neutrophil: phagocytosis; Monocyte: precursor to macrophages; Eosinophil: fight parasites; Basophil: release histamine.

• Q: What do MAC, interferon, TNF, prostaglandins, leukotrienes, interleukins do?

• A: MAC: cell lysis; Interferon: viral resistance; TNF: inflammation/apoptosis; Prostaglandins: inflammation; Leukotrienes: bronchoconstriction; Interleukins: immune cell communication.

• Q: What is the death curve in a closed system?

• A: Lag, log (exponential), stationary, death phases.

• Q: What happens at A, B, C, D in the death curve?

• A: A: lag (adaptation), B: log (growth), C: stationary (equal growth/death), D: death (decline).

• Q: What are your first, second, and third lines of defense?

• A: 1st: skin, mucous membranes; 2nd: inflammation, phagocytes; 3rd: T & B cells (adaptive immunity).

• Q: How do interferon, complement, lysozyme, transferrin, sebum, cerumen protect us?

• A: Interferon: blocks viral replication; Complement: cell lysis; Lysozyme: digests bacterial walls; Transferrin: binds iron; Sebum/Cerumen: inhibit microbial growth.

• Q: How do natural killer cells kill?

• A: By releasing perforin and granzymes to trigger apoptosis in target cells.

• Q: What are the stages in phagocytosis?

• A: Chemotaxis, adherence, ingestion, digestion, and exocytosis.

• Q: What are the signs and symptoms of inflammation?

• A: Redness, heat, swelling, pain, and loss of function.

• Q: What is inflammation?

• A: The body's response to injury or infection to eliminate cause and begin healing.

• Q: What are the different steps of inflammation?

• A: 1. Injury, 2. Chemical release, 3. Vasodilation, 4. Phagocyte recruitment, 5. Healing.

• Q: What is the difference between non-specific defense mechanism and immune response?

• A: Non-specific: general defense (innate); Immune: targeted response with memory (adaptive).

• Q: What is antibody-mediated and cell-mediated immunity?

• A: Antibody-mediated: B cells produce antibodies; Cell-mediated: T cells attack infected or abnormal cells.

• Q: What do they fight off? What do they work best against?

• A: Antibody: extracellular bacteria/toxins; Cell-mediated: viruses, fungi, cancer cells, transplants.

• Q: What cells are involved in cell- and antibody-mediated immunity?

• A: Cell-mediated: T cells; Antibody-mediated: B cells and plasma cells.

• Q: What is an antigen?

• A: Any molecule that stimulates an immune response.

• Q: What is a hapten?

• A: A small molecule that becomes antigenic only when attached to a larger carrier.

• Q: What are different types of antigens?

• A: Exogenous (outside body), endogenous (within cells), autoantigens (self).

• Q: What are complement proteins and where are they made?

• A: Plasma proteins made in the liver that enhance immune responses.

• Q: What is immunological memory?

• A: Ability of the immune system to respond faster on second exposure to an antigen.

• Q: What are antigen-presenting cells?

• A: Cells that display antigens with MHC II to helper T cells.

• Q: What are examples of antigen-presenting cells?

• A: Dendritic cells, macrophages, B cells.

• Q: What are resident flora, transient flora, commensals, mutualistic organisms?

• A: Resident: long-term microbes; Transient: temporary; Commensals: no harm/benefit; Mutualists: benefit host and microbe.

• Q: What does the normal flora do?

• A: Competes with pathogens, produces vitamins, stimulates immunity.

• Q: Why can only certain microorganisms live on your skin?

• A: Skin is dry, acidic (pH ~5.5), salty, and has antimicrobial secretions.

• Q: Where do you have the largest population of microorganisms?

• A: The large intestine (colon).

• Q: What is desquamation?

• A: Shedding of skin cells, helping remove microbes.

• Q: What is chyme?

• A: Partially digested food mixed with gastric secretions in the stomach.

• Q: What is peristalsis?

• A: Wave-like muscle contractions moving food through the digestive tract.

• Q: What are tears, and what is ciliary action?

• A: Tears contain lysozyme to wash away microbes; Ciliary action moves mucus out of the respiratory tract.

• Q: What are some things your body has that prevents organisms from attaching?

• A: Mucus, cilia, saliva, tears, skin oils, normal flora.

• Q: Where does the embryo attach?

• A: To the endometrium of the uterus.

• Q: How does a microorganism make you sick?

• A: Entry, adherence, invasion, evasion, damage (infection steps).

• Q: What are virulence factors of microorganisms?

• A: Toxins, capsules, enzymes, pili, flagella, adhesion molecules.

• Q: Which parts of your body have microorganisms and which are germ-free?

• A: Have: skin, mouth, gut, vagina; Germ-free: blood, brain, lungs, internal organs.

• Q: What are gnotobiotic animals?

• A: Animals raised in sterile conditions or with known microbes.

• Q: What is a commensal and a mutualistic relationship?

• A: Commensal: one benefits, other unaffected; Mutualistic: both benefit.

• Q: What is the pH of the skin and stomach?

• A: Skin ~5.5; Stomach ~1.5–3.5 (very acidic).

• Q: How do you inhibit mycoplasmas?

• A: Use antibiotics like tetracycline; they lack cell walls, so penicillin is ineffective.

• Q: What part of your body is sterile and what part has normal flora?

• A: Sterile: internal organs, blood; Flora: skin, gut, mouth, vagina.

• Q: What are characteristics of normal flora that let them live on your body?

• A: Adaptation to pH, nutrients, resistance to host defenses, biofilm formation.

• Q: Duodenum, jejunum, and ileum—what kind of bacteria are there?

• A: Duodenum: few due to bile/acidity; Jejunum: some Gram-positive; Ileum: more, including Gram-negative anaerobes.

• Q: Who first examined gnotobiotic animals?

• A: Louis Pasteur and later researchers refined sterile animal techniques.

• Q: What does the normal flora do for you?

• A: Protects against pathogens, aids digestion, modulates immunity, produces vitamins.

• Q: What are the two cytotoxic or killer T cells?

• A: Cytotoxic T cells (CD8+) and Natural Killer (NK) cells.

• Q: What is cell-mediated immunity and what does it target?

• A: It involves T cells and targets viruses, fungi, cancer cells, and transplanted organs.

• Q: What is antibody-mediated immunity and what does it target?

• A: It involves B cells and targets extracellular bacteria and toxins.

• Q: Do these immunities target viruses, fungi, bacteria, cancer cells, transplanted organs, RH factor?

• A: Yes. Cell-mediated targets viruses, fungi, cancer, transplanted organs; antibody-mediated mainly targets bacteria and toxins. RH factor is a target in some antibody responses (e.g., hemolytic disease of the newborn).

• Q: What are the steps of inflammation?

• A: 1. Injury, 2. Chemical release, 3. Vasodilation, 4. Phagocyte migration, 5. Repair.

• Q: What is the criteria for the immune response?

• A: Specificity, memory, and self vs non-self recognition.

• Q: What is the antigenic determinant?

• A: The specific part of an antigen that is recognized by antibodies (epitope).

• Q: What is the heavy chain and light chain of an antibody made of?

• A: Proteins; heavy and light chains are polypeptides held by disulfide bonds.

• Q: What are IgA, IgG, and IgM, what percentage are each, where do they reside, and what do they do?

• A: IgG (75%, blood, long-term immunity), IgA (15%, secretions, mucosal protection), IgM (5–10%, blood/lymph, first response).

• Q: Which antibody is most in circulation and which is first when exposed?

• A: IgG is most in circulation; IgM is the first made in response to infection.

• Q: Where do you find antigen-presenting cells and what are their types?

• A: Found in tissues, lymph nodes, and spleen. Types: dendritic cells, macrophages, B cells.

• Q: What are the stages in phagocytosis?

• A: Chemotaxis, adherence, ingestion, digestion, exocytosis.

• Q: How long does it take to kill something with phagocytosis?

• A: Minutes to hours depending on the pathogen.

• Q: What are the types of immunity and examples of each?

• A: Naturally active: infection; Naturally passive: breast milk; Artificially active: vaccine; Artificially passive: antibody injection.

• Q: Where do you find fixed macrophages and what are their names?

• A: In tissues: Kupffer (liver), microglia (brain), alveolar (lungs), etc.

• Q: What is a neutrophil?

• A: A fast-responding phagocyte; first at infection site.

• Q: What is a monocyte?

• A: A precursor to macrophages and dendritic cells found in blood.

• Q: What is a macrophage?

• A: A large phagocyte derived from monocytes; can present antigens.

• Q: What are natural killer cells?

• A: Lymphocytes that kill infected or cancerous cells without MHC recognition.

• Q: Where are natural killer cells found?

• A: Blood, spleen, liver, lungs.

• Q: What is the first type of blood cell to arrive at an infection?

• A: Neutrophils.

• Q: What is the membrane attack complex (MAC) and what does it do?

• A: A complex from complement proteins that forms pores in target cell membranes, causing lysis.

• Q: What is opsonization?

• A: Coating of a pathogen by antibodies or complement to enhance phagocytosis.

• Q: What are the functions of the complement system?

• A: Opsonization, inflammation promotion, and cell lysis via MAC.

• Q: Where do T cells and B cells mature?

• A: T cells in thymus; B cells in bone marrow.

• Q: What is an antigen?

• A: A substance that triggers an immune response.

• Q: What is a pathogen?

• A: A disease-causing microorganism.

• Q: What is specific resistance?

• A: Targeted immune response involving memory (adaptive immunity).

• Q: What is non-specific resistance?

• A: General defenses like skin, fever, inflammation (innate immunity).

• Q: What is resistance?

• A: The body's ability to fend off disease.

• Q: What is pathogenicity?

• A: The ability of a microbe to cause disease.

• Q: What is susceptibility?

• A: Lack of resistance to disease.

• Q: What is immunity?

• A: Ability to resist infection or disease.

• Q: What is an epidemic?

• A: Sudden disease outbreak in a community.

• Q: What is a pandemic?

• A: Global disease outbreak.