Please enable JavaScript.
Coggle requires JavaScript to display documents.
11.2 Cells of the immune system - Coggle Diagram
11.2 Cells of the immune system
Phagocytes
Neutrophils
Short-lived
Form 60% of white blood cells
Leave the blood by squeezing through capillary walls
Macrophages
Travel through the blood as monocytes, develop into macrophages once leaving the blood
Long-lived
Cut up pathogens to display their antigens for recognition by lymphocytes
Produced in bone marrow
Innate immune system
Phagocytosis
Attraction
Recognition and attachment
Endocytosis
Containment in phagocytic vacuole
Fusion of lysosomes and phagocytic vacuole
Killing, digestion, exocytosis
Lymphocytes
Large nucleus
B-lymphocytes/B cells
Remain in bone marrow until mature
Spread around the body when mature, mostly in lymph nodes and spleen
As they mature, the genes that code for antibodies are changed
Maturation phase = clonal selection
When they detect their specific antigen, they activate
Some become plasma cells
Short-lived
Secrete antibodies
Some become memory cells
Long-lived
Undergo clonal expansion upon reactivation by specific antigen
Responsible for secondary immune response
Faster than primary immune response
More specific B cells present
Activation phase = clonal expansion
T-lymphocytes/T cells
Leave bone marrow and collect in thymus gland
Have same clonal selection and clonal expansion as B-cells
T-helper cells
Release cytokines, activating B cells and stimulating macrophages
T-killer cells
Recognise and kill cells that display foreign antigens on their cell surface membranes, indicating that they are infected
Each type is specific to one antigen
Adaptive immune system
Antibodies
Consist of four polypeptide chains
Two heavy, two light
Held together by disulphide bonds
Hinge region gives flexibility to bind to antigens
Combine with viruses, preventing cell entry
Attach to bacterial flagella, reducing mobility
Cause agglutination (clumping together) of bacteria
Assist with punching holes in bacterial cell walls, causing lysis
Aid in phagocytosis by covering bacteria
Combine with toxins, neutralising them and rendering them harmless