5.3 Subdivisions of immunity

innate immunity

the type of immunity that is present from birth, is fast acting but not long lasting, and produces non-specific responses against classes of pathogens

adaptive immunity

an immune response that is specific to a particular antigen and develops through contact with an antigen

cell-mediated immunity

immune responses that is mediated by immune cells

humoral immunity

immune response mediated by soluble molecules in the blood, lymph and interstitial fluid that disable pathogens

first line of defence

part of the defence against pathogens provided by barriers of the innate immune system that prevent entry of pathogens into the body e.g skin

second line of defence

part of the defence provided by the immune cells and soluble proteins of the innate immune system against attacking pathogens that gain entry to the body e.g inflammation

third line of defence

part of the defence provided by the immune cells of the adaptive immune system through the various actions of T cells and B cells

immunological memory

ability of the adaptive immune response to remember antigens after primary exposure

memory cells

long-lived cells specific to an antigen that are retained in lymph nodes and can respond to future reinfection

lymphocytes

class of white blood cells found in all tissues including blood, lymph nodes and spleen, and which play a role in specific immunity

B lymphocytes

also called B cells; white blood cells that recognise antigens or pathogens adn produce a large number of antibodies specific to an antigen

T lymphocytes

also called T cells; white blood cells that mature in the thymus and participate in the adaptive immune response

lymph nodes

organs of the lymphatic system where B cells and T cells are activated and adaptive immune responses occur

neutrophils

the most common type of white blood cell; one kind of phagocyte