Immune System

Tonsils Adenoids Spleen Lymph nodes Lymph vessels Thymus Bone marrow

Haemopoiesis (forming blood cells)

Recognise and kill pathogens/infected cells Remove dead cells Wound healing Surveillance/removal of cancerous cells

Granulocytes- have specific granules in cytoplasm eg neutrophils, eosinophils, basophils Lymphocytes- T cells, B cells, natural killer cells Monocytes- found in blood only, immature

Target bacteria/fungi Found in bloodstream and tissues First line of defence (innate, non specific)

Attack parasites - release hydrolytic enzymes Involved in allergic reaction

Like Large tissue mast cells located outside capillaries in the body Mast cells and basophils release histamines, bradykinkin and serotonin Role in allergic reaction

Type of white blood cell Derived from monocytes, found in tissue e.g alveolar macrophages in lungs, microglia (macrophages of CNS)

Non specific, first line of defence Neutrophils, monocytes, macrophages, granulocytes, natural killer cells (Cell mediated) Fast response Phagocytosis

Neutrophils (cytokines, chemotaxis) Macrophages and monocytes (same cell different location) Organ specific macrophages

Nonspecific short acting resistance to viral infection Act as messengers that protect other cells in the vicinity from viral infection

Alpha Beta Gamma

Cytokines that cause a fever eg interleukin, stimulate hypothalamus to raise temp and induce fever. Inhibits bacteria, increases neutrophil and interferon production

Phagocyte attracted to pathogen by surface antigens/chemoattractants, move via chemotaxis Engulf pathogen in phagocytic vacuole Lysosome fused with vacuole and releases lysozymes Lysozymes hydrolyse pathogen Phagocyte presents pathogens antigens on surface, becomes an antigen presenting cell

Physiological response to infection (swelling, heat, pain, redness) -Vasodilation to increase blood flow to effected area (increased action of neutrophils) -increased vascular/capillary permeability, fluid leaks into interstitial spaces -increased clotting factors -pus formation (dead cells) -increased production of granulocytes/monocytes by bone marrow -walling off inflammation to specific area so infection doesn’t spread (clotting mesh formed) -neutrophilia (overproduction of neutrophils)

Aquired, specific to attacking pathogen Second line of defence (Humoral) T cells , B cells, antibodies

Cell mediated- T cells, b cells Humoral - Antibidies

Helper T Cytotoxic T/ killer T Suppressor T Memory T

Antigen presenting cells (e.g macrophage /phagocyte) contain MHC proteins that stick to antigen of pathogen MHC 1 proteins present antigens to cytotoxic T cells MHC 2 proteins present antigens to helper T cells

Kickstart the immune response and regulate it Activated macrophage system Produce lymphokines eg interleukin -1 that act on the immune system eg to stimulate macrophage production Stimulates B cell growth- differentiation into plasma cells- antibodies Stimulates cytotoxic T cells

Directly kills microorganisms / cancer cells/ sometimes own body cells Bind to pathogen and secrete perforins, create holes in pathogen, release cytotoxic substances into cell

Suppress action of cytotoxic T cells to prevent harm to body cells

Produced after primary response 2nd exposure= memory T cells released, faster response

B cell- lymphoblast- plasmablast- antibodies (Memory b cells)