A mass of lymphatic tissue that help protect the body by removing foreign material such as bacteria and tumor cells from the lymphatic stream and by producing lymphocytes that function in the immune response
phagocytic cell abundunt in lymphatic and connective tissues; important as an antigen-presenter to T cells and B cells in the immune system.
they include the spleen, thymus gland, tonsils, lymph nodes, and peyer's patches of the intestine. the common feature is a predominanceof reticular connective tissue and lymphocytes.
A blood-rich organ that filters blood of bacteria, viruses, and other debris. It destroys worn-out RBC. It is located in the left side of the abdominal cavity.
lymphatic mass found low in the throat overlying the heart. functions during youth. produces thymosin which functions in the programing of certain lymphocytes.
small masses of lymphatic tissue that ring the pharynx. Their job is to trap and remove any bacteria or other foreign pathogens entering the throat
found in the wall of the small intestine. they capture and destroy bacteria, thereby preventing them from penetrating the intestinal wall.
Acts as sentinel to protect the upper respiratory and digestive tracts from the never-ending attacks of foreign matter entering those cavites.
Nonspecific Defense System
responds immediately to protect the body from all foreign substances, whatever they are. Ex. Skin, mucous membranes.
Specific Defense System
The immune system. It mounts the attack against particular foreign substances.
The ability of the body to resist many agents (both living and nonliving) that can cause disease; resistance to disease.
a cell capable of engulfing and digesting particles or cells harmfull to the body much the way and amoeba engulfs food. It engulfs pathogens that make it through the mechanical barriers.
Natural Killer Cells (NK)
A unique group of defensive cells that can lyse and kill cancer cells and virus-infected body cells well before the immune system is enlised in the fight. they "police" the body in blood and lymph.
the fluid product of inflammation composed of a mixture of dead or dying neutrophils, broken-down tissue cells, and living and dead pathogens.
A group of at least 20 plasma proteins that normally circulate in inactive forms; when activated by complement fixation, causes lysis of foreign cells and enhances phagocytosis and inflammation.
chemicals secreted by white blood cells and macrophages exposed to foreign cells or substances in the body. They help induce fever.
The immune system's response to a threat. It is antigen specific, systemic, and has "memory"
Antigens that do not trigger an immune response in us, but they are strongly antigenic to other people.
The ability of the body's immune cells to recognize (by binding) specific antigens; reflects the presence of plasma membrane-bound receptors.
B cell clone members that do not become plasma cells become long-lived memory cells capable of responding to the same antigen at later meetings with it. Provides immunologic memory.
second and subsequent responses of the immune system to a previously met antigen; more rapid and more vigorous than the primary response.
Immunity produced by B cells by the encounter with an antigen, provides immunologic memory. It is either naturally acquired, or artificially acquired.
short-lived immunity resulting from th introduction of "borrowed antibodies" obtained from an immune animal or human doner; immunological memory is not established.
a specialized substance produced by the body that can provide immunity against a specific antigen.
Occurs when antibodies bind to specific sites on bacterial exotoxins or on viruses that can cause cell injury. In this way, they block the harmful effects of the exotoxin or virus.
Cytotoxic Killer T Cells
effector T cells that directly kills foreign cells, and body cells that have become cancerous.
Helper T Cells
A regulatory T cell that binds with a specific antigen presented by a macrophage; it stimulates the production of other immune cells (killer T cells and B cells) to help fight the invader; acts both directly and indirectly by releasing lymphokins
Suppressor T Cells
Slows or stops the activity of B and T cells once the infection (or attack by foreign cells) has been conquered.
Delayed Hypersensitivity T Cells
effector cells that play a major role in cell-mediated allergies and long-term, or chronic, inflammations.
Memory T Cells
T cells that remain alive to provide the immunological memory for each antigen encountered and enable the body to respond quickly to its subsequent invasions.
abnormally vigorous immune responses in which the immune system causes tissue damage as it fights off a perceived "threat" that would otherwise be harmless to the body.
It causes allergic response. it is distinguished from antigens producing essentially normal responses
include both congenital and acquired conditions in which the production or function of immune cells or complement is abnormal.