Chapter 5: Cell recognition and the immune system Flashcards

Question

Specification: Describe the first line of defence against disease.

Answer 1

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skin - physical barrier
airways - mucus
scalp - oils such as sebum, antimicrobial
eyes - tears
stomach - acid

Answer 2

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invloves B-cells floating around in the fluids of the body B-cells Unlike T-cells, B-cells do not attack pathogens directly. Instead, they
remain in the lymphoid tissues (spleen, lymph nodes) and produce
antibodies that facilitate in the destruction of the pathogen

Answer 3

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B-cells mature in the bone marrow

Answer 4

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T-cells mature in the thymus gland

Answer 5

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a pathogens infects a host cell or is engulfed by a
specific helper t cell
activates t cell to divide form clones
some become memory
some
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Answer 6

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Phagocytes engulf any pathogens/antigens and are able to activate T-cells. T-cells go on to activate B-cells and B-cells divide into plasma cells which secrete antibodies that are specific to an antigen and help to destroy it.

Answer 7

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A type of white blood cell. It is part of the immune system and its main job is to carry out phagocytosis, that is to engulf and destroy foreign pathogens/viruses/bacteria/microbes and to get rid of waste materials

Answer 8

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T-cells bind to the antigens presented on the surface of an AP phagocyte
T-cells have receptor proteins on their surface complimentary to specific antigens
binding stimulate T-cells to divide and form clones
clones differentiate into different types of cells: some become memory cells, killer/cytotoxic T-cells, and memory cells

Answer 9

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T-lymphocytes are white blood cells that develop in the thymus, and are concerned not only with
cellular immunity but also with the regulation of the humoral response by the B-lymphocytes

Answer 10

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B-lymphocytes make antibodies in the humoral response to infection, and are found in the lymphoid organs (except thymus)

Answer 11

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Immunity: The ability to be resistant to infection, particularly by poisons, foreign proteins and invading parasites, due to the presence of antibodies and memory cells

Answer 12

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A substance, that when introduced into the tissues or blood activates the immune system which is induced to form antibodies. The antibodies are specific to the antigen and react with it to make it harmless. Antigens may be
protein, lipoprotein, nucleoprotein, glycoprotein or sometimes large polysaccharides. They may be components of bacteria, viruses, pollen,
egg white, incompatible blood cells or cells from transplanted organs, or abnormal/cancerous body cells. Toxins released by some bacteria and viruses may also act as antigens

Answer 13

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A type of phagocyte. (Phagocyte is a generic or broad term for cells that are capable of engulfing small particles)

Answer 14

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Kill abnormal and invaded cells
by releasing perforin
a protein that creates holes in the cell surface membrane
so that cell membrane becomes freely-permeable
and the cell therefore dies

Answer 15

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activate B-cells which induces antibody production
release a chemical signal (interleukin 2, a lymphokine) that stimulates phagocytes and cytotoxic T-cells
therefore enhancing the immune response

Answer 16

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Are programmed to remember the original antigen that caused the initial immune response. They remain stored in the tissue and if the same antigen is encountered again it can be destroyed before disease symptoms occur