Body Defenses Flashcards
acquired immune responses
Responses that are selectively targeted against particular foreign material to which the body has previously been exposed; see also antibody-mediated immunity and cell-mediated immunity
allergy
Acquisition of an inappropriate specific immune reactivity to a normally harmless environmental substance
antibody-mediated immunity
A specific immune response accomplished by antibody production by B cells
antigen
A large, complex molecule that triggers a specific immune response against itself when it gains entry into the body
asthma
An obstructive pulmonary disease characterized by profound constriction of the smaller airways caused by allergy-induced spasm of the smooth muscle in the walls of these airways
autoimmune disease
Disease characterized by erroneous production of antibodies against one of the bodyUs own tissues
B lymphocytes (B cells)
White blood cells that produce antibodies against specific targets to which they have been exposed
cell-mediated immunity
A specific immune response accomplished by activated T lymphocytes, which directly attack unwanted cells
chemotaxin
A chemical released at an inflammatory site that attracts phagocytes to the area
complement system
A collection of plasma proteins that are activated in cascade fashion on exposure to invading micro-organisms, ultimately producing a membrane attack complex that destroys the invaders
cortisol
The adrenocortical hormone that plays an important role in carbohydrate, protein, and fat metabolism and helps the body resist stress
cytokines
All chemicals other than antibodies that are secreted by lymphocytes
cytotoxic T cells
The population of T cells that destroys host cells bearing foreign antigen, such as body cells invaded by viruses or cancer cells
dendrites
Projections from the surface of a neuronUs cell body that carry signals toward the cell body
dermis
The connective tissue layer that lies under the epidermis in the skin; contains the skinUs blood vessels and nerves
endogenous pyrogen
A chemical released from macrophages during inflammation that acts by means of local prostaglandins to raise the set point of the hypothalamic thermostat to produce a fever
epidermis
The outer layer of the skin, consisting of numerous layers of epithelial cells, with the outermost layers being dead and flattened
fight-or-flight response
The changes in activity of the various organs innervated by the autonomic nervous system in response to sympathetic stimulation, which collectively prepare the body for strenuous physical activity in the face of an emergency or stressful situation, such as a physical threat from the outside environment
helper T cells
The population of T cells that enhances the activity of other immune-response effector cells
histamine
A chemical released from mast cells or basophils that brings about vasodilation and increased capillary permeability; important in allergic responses
host cell
A body cell infected by a virus
immune surveillance
Recognition and destruction of newly arisen cancer cells by the immune system
immunity
The bodyUs ability to resist or eliminate potentially harmful foreign materials or abnormal cells
immunoglobulin
Antibodies; gamma globulins
inflammation
An innate, nonspecific series of highly interrelated events, especially involving neutrophils, macrophages, and local vascular changes, that are set into motion in response to foreign invasion or tissue damage
innate immune responses
Inherent defense responses that nonselectively defend against foreign or abnormal material, even on initial exposure to it; see also inflammation, interferon, natural killer cells, and complement system
interferon
A chemical released from virus-invaded cells that provides nonspecific resistance to viral infections by transiently interfering with replication of the same or unrelated viruses in other host cells
interleukin 1
A multipurpose chemical mediator released from macrophages that enhances B cell activity
interleukin 2
A chemical mediator secreted by helper T cells that augments the activity of all T cells
keratin
The protein found in the intermediate filaments in skin cells that give the skin strength and help form a waterproof outer layer
killer (K) cells
Cells that destroy a target cell that has been coated with antibodies by lysing its membrane
leukocyte endogenous mediator (LEM)
A chemical mediator secreted by macrophages that is identical to endogenous pyrogen and exerts a wide array of effects associated with inflammation
lymphoid tissues
Tissues that produce and store lymphocytes, such as lymph nodes and tonsils
mast cells
Cells located within connective tissue that synthesize, store, and release histamine, as during allergic responses
melanocyte-stimulating hormone (MSH)
A hormone produced by the anterior pituitary in humans and by the intermediate lobe of the pituitary in lower vertebrates; regulates skin coloration by controlling the dispersion of melanin granules in lower vertebrates; involved with control of food intake and possibly memory and learning in humans
membrane attack complex
A collection of the five final activated components of the complement system that aggregate to form a porelike channel in the plasma membrane of an invading micro-organism, with the resultant leakage leading to destruction of the invader
memory cells
B or T cells that are newly produced in response to a microbial invader but that do not participate in the current immune response against the invader: instead they remain dormant, ready to launch a swift, powerful attack should the same micro-organism invade again in the future
natural killer cells
Naturally occurring, lymphocyte-like cells that nonspecifically destroy virus-infected cells and cancer cells by directly lysing their membranes on first exposure to them
opsonin
Body-produced chemical that links bacteria to macrophages, thereby making the bacteria more susceptible to phagocytosis
pathogens
Disease-causing micro-organisms, such as bacteria or viruses
phagocytosis
A type of endocytosis in which large, multimolecular, solid particles are engulfed by a cell
plasma cell
An antibody-producing derivative of an activated B lymphocyte
self-antigens
Antigens that are characteristic of a personUs own cells
T lymphocytes (T cells)
White blood cells that accomplish cellmediated immune responses against targets to which they have been previously exposed; see also cytotoxic T cells, helper T cells, and suppressor T cells
thymus
A lymphoid gland located midline in the chest cavity that processes T lymphocytes and produces the hormone thymosin, which maintains the T cell lineage
virulence
The disease-producing power of a pathogen
