MCB 3020 – FINAL Exam Questions With Verified Solutions

MCB 3020 – FINAL Exam Questions With Verified Solutions Humoral immunity is mediated by - answerantibodies Cellular immunity is mediated by - answerT-cells Mechanical barriers - answer1) Skin 2) Mucous membranes 3) Tears 4) Respiratory tract Very few microorganisms penetrate skin True or False? - answerTrue What do tears contain? - answerLysozymes What kind of epithelium covers respiratory tract? - answerciliated epithelium Natural resistance (innate immunity) includes - answer1) Cells: macrophages, etc 2) Mechanical barriers: skin & mucous membranes 3) Chemical factors: interferons, fatty acids on skin 4) Microbial factors Chemical factors of natural resistance (innate immunity) - answer1) Fatty acids 2) Bile salts 3) Lysozyme 4) Phagocytins 5) Complement 6) Interferon What type of bacteria is attacked by fatty acids? - answergram-negative on skin surface Where are bile salts located and what kind of bacteria they inhibit? - answerin gall bladder, liver, intestines inhibit gram positive Lysozyme is more effective agains what type of bacteria? - answergram-positive Phagocytes are in - answerleukocytes (white blood cells) In the presence of complement what happens to microbial cell membranes? - answermicrobial cell membranes and some cancer cells can lose physical integrity and lyse Interferon is active against? - answerViruses Microbial factors if innate immunity - answerNormal flora on the body provides protection by competition with pathogens: example: gram + making fatty acids on the skin If normal flora is damaged by antibiotics what happens? - answerindividual can get fungus infection When a pathogen breaks through physical and chemical defenses, what is the first cell that it encounter? - answerPhagocytic cell What is the primary function of phagocytic cell? - answerEngulf and destroy pathogens Phagocytes can also acts as - answerantigen-presenting cells (APC's) and generate a peptide antigen (s) that will activate specific immune responses 3 main types of phagocytes - answer1) Neutrophils (polymorphonuclear leukocytes) 2) Monocytes 3) Macrophages Neutrophils - answeractively motile granulocytes containing large # of lysozymes What is produces in phagocytes to destroy pathogens? - answerToxic oxygen compounds Toxic compounds include - answer1) Hydrogen peroxide (H2O2) 2) Superoxide anions (O2-) 3) Hydroxyl radicals (OH-) 4) Singlet oxygen (1O2) 5) hypochlorous acid (HOCl) 6) Nitric oxide (NO)