8 Cell recognition and the immune system Flashcards
What does immunity mean?
the ability to resist invading pathogens
What is an immune response?
organism recognising and responding to antigens and destroying cells hosting non-self antigens through activation of lymphocytes
What are the 2 types of lymphocytes?
T cells (cell-mediated immunity); thymus gland
B cells (humoral immunity); bone marrow
What are the 2 types of white blood cell?
lymphocytes and phagocytes
Definition for an antibody
a protein produced by a B lymphocyte/ B plasma cell in response to presence of a non-self antigen
Definition for antigen
a molecule, usually a protein, that triggers an immune response
What is the process called whereby a type of white blood cell engulfs and destroys a pathogenic microorganism?
phagocytosis
What antigens can the immune system identify?
pathogens; cells from other organisms of same species; abnormal body cells; toxins
What would a non-self antigen trigger?
an immune response
What is a phagosome?
the vesicle formed when a phagocyte engulfs a pathogen
What does a lysosome contain?
lysozyme and other hydrolytic enzymes to digest/ break down pathogen
What are the roles of T helper cells and cytotoxic T cells in the cellular response?
T helper cells bind with antigens on surface of antigen-presenting cells then stimulate other T cells to divide by mitosis to form a clone; cytotoxic T cells kill infected cells by making holes in their cell surface membranes
What are the 2 types of B lymphocytes involved in the humoral response? Briefly explain their functions
plasma cells- produce antibodies; short-lived ; have main role in primary immune response
memory cells- long lived; respond to re-exposure to specific antigens when they then divide rapidly to form plasma cells and more memory cells; main role in secondary immune response
