week 2 immunology Flashcards
what are the characteristics of the innate immune system
- non-specific
- distinguishes between human cells and pathogens but not between different types of pathogens
- fast and immediate
- no memory
what are the characteristics of the adaptive immune system
- highly specific
- distinguishes between different pathogens based on antigens
- slower: can take a few days to develop
- immunological memory
what are the two subcategories of innate immunity
cellular - phagocytes - eosinophils, mast cells - basophils (in that order) humoral - complement system - cytokines (happening simultaneously)
what are neutrophils
- phagocyte
- most abundant white blood cell
- they contain granules that are filled with many destructive enzymes such as peroxides, alkaline and acid phosphates which are responsible for kill and destroying bacteria and other pathogens
what are monocytes
- phagocyte
- bigger than neutrophils (can engulf more)
- in blood
- macrophages when in tissue
what do macrophages do
macrophages break down pathogens, process antigens and present these antigens to T cells and antibodies
- they are antigen presenting cells (APCs)
what are the stages of phagocytosis
- movement of the phagocyte toward the microbe
- attachment of microbes to phagocyte surface
- endocytosis of microbe and formation of phagosome
- fusion of phagosome with lysosome
- killing of microbe through digestion by enzymes
- discharge of waste material
what are eosinophils
- help combat parasitic infections
- involved in allergy and asthma
- granules contain many enzymes
what are basophils
- least common of the white blood cells
- contain large granules with inflammatory mediatiors
- no proven function
- found in parasitic infection
what are cytokines
- part of the humoral category of the innate immune system
- they are small proteins secreted by both immune and some non-immune cells in response to stimulus
what do cytokines do
- they communicate with other cells
- they bind to specific receptors on these cells producing a signalling molecule that leads to many biological effects
- they are key players in innate and acquired immunity: differentiation, activation, chemotaxis, enhancing cytotoxicity
what is humoral immunity
- AKA antibody mediated immunity
- involves helper T cells and B cells
- category of the adaptive immune system
what is cellular immunity
- involves phagocytes, cytotoxic T cells, cytokines and chemokines
- part of the innate immune system
what is the development process of lymphocytes
- production of B and T cells usually takes place in the bone marrow
- when they are maturing T cells gain T cell receptors and B cells gain B cell receptors
- activated by reaction with pathogen
what is the role of the lymphatic system
- drainage of tissue
- absorption and transport of fatty acids and fats
- immunity
what are the components of the lymphatic system
- lymphatic vessels
- lymphatic organs (primary and secondary)
what are the primary lymphoid organs
where blood cells are produced and receive their ‘early training’ (acquire ability to interact with antigens)
- bone marrow
- thymus
what are red blood cells, platelets and myloblasts formed from
myeloid stem cells
what do myeloblasts go on to become
granulocytes
- eosinophils
- basophils
- neutrophils
what are the steps of erythropoiesis (red blood cell formation)
- pluripotent haematopoietic stem cell
- uncommitted stem cell
- committed progenitor cell
- erythroblast
- reticulocyte
- erythrocyte
where is the site of T cell maturation
- T for Thymus
cortex = mature T lymphocytes
medulla = immature T lymphocytes and macrophages - so mature as they move through the thymus
what are secondary lymphoid organs
sites of lymphocyte activation by antigens
- lymph nodes
- spleen
- mucosal immune system
- tonsils