A Level Biology: Primary Non-Specific Defences against Pathogens Exam

Give three examples of exchange surfaces that are thinner and less protected from infection - answer-air ways, lungs, digestive system What physical non-specific defence protects epithelial cells on exchange surfaces from pathogens? - answer-mucous membranes What cells produce mucus? - answer-goblet cells Where are mucous producing glands found? - answer-under the epithelium What two things does mucous contain that removes pathogens? - answer-lysozymes and phagocytes What is the role of lysozymes in mucus? - answer-to break down bacterial and fungal cell walls What is the role of cilia in the mucociliary escalator ? - answer-to waft mucous along the top of the trachea where it can be swallowed How is the stomach involved in the mucociliary escalator? - answer-pathogens are killed by the acidity of the stomach as the low pH denatures pathogen's enzymes Give 4 examples of when mucous membranes are found in the body other than the trachea - answer-nose, ear, anus, genitals Give three examples of expulsive reflexes - answer-coughing, sneezing, vomiting What is the role of expulsive reflexes? - answer-to expel pathogens from the body Give four symptoms of inflammation - answer-redness, swelling, heat, pain What cells detect microorganisms entering the body which release histamine which thus causes inflammation? - answer-mast cells What cell signalling substance do mast cells produce that causes inflammation? - answer-histamine What effect does histamine have that causes inflammation? - answer-vasodilation of arterioles and increased permeability of capillary walls that allows blood plasma and phagocytic white blood cells to enter tissue fluid What is another term for swelling? - answer-oedema What is the result of increased phagocytes and blood plasma entering tissue fluid during inflammation? - answer-swelling