immune system function and organs

helper/ inducer t-cells

CD4 involved in activating and directing the actions of other immune cells as follows. -secrete cytokines that activate macrophages -assist B-cells in antibody production -activate suppressor cells

cytotoxic t-cells

CD8 cells attack and lyse cells infected with viruses, tumor cells, bacteria, and cells that are damaged and/ or otherwise dysfunctional

natural killer cells

NK cells. large granular lymphocytes that have the unique ability to lyse virally infected cells, malignant cells, and antibody-antigen complexes without prior antigenic stimulation.

mucosa

associated lymphoid tissues (MALT). system composed of small concentrations of lymphoid tissue. it provides the first line of defense against orally ingested pathogens.

monocytes

become macrophages when entering the tissue. engulf and ingest antigens via phagocytosis. serve as antigen-presenting cells APC that process and present antigens to lymphocytes during immune response.

lymph nodes

bundles of tissue that can be found throughout the human body. filled with lymphocyte cells, they act as filters, removing microorganisms from circulation.

suppressor t-cells

cells inhibit the activities of b-cells or t-cells in order to keep the immune response from going out of control

immune response

complex and broad range of defensive mechanisms that the human body uses to combat infections and diseases. -first line of defense -natural or innate immunity -acquired or adaptive immunity -antigenicity (immunogenicity) ability of antigen to stimulate ____

b-lymphocytes

develop in bone marrow. responsible for humoral immunity. activate and start producing antibodies (plasma cells) encountering a specific antigen, actively begins multiplying without affecting the rest of the cell population. only responds to a small number of different antigen types.

thymus

found in the trachea where some of the special stem cells from the bone marrow undergo further development in order to become T-lymphocytes (T cells)

basophils

granulocyte. cells accumulate at inflammatory site release histamines, causing allergic response. activated by IgE anitbodies

neutrophils

granulocyte. purpose phagocytosis. granules break down ingested material and kill microorganisms

Antigen presenting cells

immune cell capable of taking up parts of antigens and presenting them to lymphocytes, display parts of ingested antigens, bound Major histocompatibility complex molecules on their surfaces. -antigen ingested by APC and broken down into smaller pieces -vesicle containing MHC molecules merges with vesicle containing the antigen pieces -antigen fragments become bound to MHC molecules and the antigen-MHC complexes are exported to the surface of the APC -according to which type of antigen-MHC complex is exposed, either helper/inducer T-cells (CD4) or cytotoxic cells (CD8) are activated.

Natural Immunity

initial response for removal of microbes. born with. non-antigen specific. non-adaptive. responses do not improve with repeated exposure to a given infection. Cellular components: Mast Cells, Neutrophils, Macrophages Humoral Components: Complement Proteins, Lysozymes, Interferons

immune system

intricate system of organs, cells, and organic structures which work together to defend the human body from he multitude of biological threats it faces every day.

eosinophils

kill invading organisms including certain parasites. Control allergic reactions but emitting histaminase.

surveillance

one of the additional functions of the immune system recognizes and destroys malignant cells before they are able to spread and cause further harm

defense

one of the additional functions of the immune system. defends the body from microorganisms that could cause it harm or even death.

homeostasis

one of the additional functions of the immune system. helps maintain homeostasis by removing old and or damaged cells from the body.

Primary lymphoid organs

organs responsible for the production and development of special cells. bone marrow, thymus

t-lymphocytes

originate in bone marrow but mature in thymus. primary cells responsible in cell-mediated immunity. represent 60-80% of circulating lymphocytes.

immune system main function

recognize structures as being "self" or "non-self"

adaptive immunity

secondary defense mechanism. immunity you acquire. antigen specific. adaptive: allows body to remember and to respond more effectively to reencountered antigens. Cellular components: antigen presenting cells, macrophages, t-lymphocytes, b-lymphocytes and plasma cells humoral components: antibodies, cytokines

secondary organs

serve as a filtration system that eliminates both debris and foreign molecules. mucosa, lymph nodes, spleen

bone marrow

spongy fatty tissue found inside long bones. Site of most cell development and maturation. B-lymphocytes (B cells) develop and mature

spleen

the largest of the secondary organs, the spleen acts as a filter, trapping and removing foreign material out of the blood. it also removes both older and damaged RBCs.