CONCEPT REVIEW (Immunity) Flashcards
The ability to ward off disease is called immunity (resistance). Lack of resistance is called.
susceptibility
Innate (nonspecific) immunity is always present to provide
rapid responses against disease.
Adaptive (specific) immunity develops in response to
specific pathogens when they have
surpassed innate immunity defenses.
The lymphatic system drains interstitial fluid, __________________, and protects against invasion.
transports dietary lipids
What is the lymphatic system made up of?
The lymphatic system consists of lymph, lymphatic tissues, and red bone marrow.
Lymphatic tissue is specialized reticular tissue containing large numbers of?
lymphocytes
What does The lymphatic system
The lymphatic system drains excess interstitial fluid, transports lipids, and carries out immune responses against invasion.
Lymph capillaries merge to form larger vessels, called lymphatic vessels, which convey lymph into and out of ___________________.
lymph nodes.
The route of lymph flow is from lymph capillaries to lymphatic vessels, to lymph _________, then to the thoracic duct and right lymphatic duct.
trunks
What are the lymphatic organs?
The lymphatic organs and tissues include the thymus, lymph nodes, spleen, and lymphatic follicles.
What are the primary lymphatic organs? What happens there?
Primary lymphatic organs and tissues are the sites where stem cells divide and develop into immunocompetent B cells and T cells. They are the red bone marrow and the thymus.
What are the secondary organs and tissues? What happens there?
Secondary lymphatic organs and tissues are the sites where most immune responses occur. They include lymph nodes, the spleen, and lymphatic follicles.
The thymus lies _____________ to the sternum and ____________ to the heart. It is the site of T cell maturation.
posterior
superior
Lymph nodes are located along ____________. Lymph enters lymph nodes through __________lymphatic vessels, is filtered, and exits through __________ lymphatic vessels.
lymphatic vessels
afferent
efferent
What is the largest mass of lymphatic tissue in the body?
The spleen is the largest mass of lymphatic tissue in the body
What does the spleen do?
It is a site where B cells divide into plasma cells and macrophages phagocytize wornout red blood cells and platelets
What are Lymphatic follicles?
Lymphatic follicles are concentrations of lymphatic tissue that are not surrounded by a capsule
Where are Lymphatic follicles found?
They are scattered throughout the mucosa of the gastrointestinal, respiratory, urinary, and reproductive tracts and are termed mucosaassociated lymphatic tissue (MALT). Tonsils are examples of lymphatic follicles
Innate (nonspecific) immunity includes physical factors, chemical factors, _______________, phagocytes, inflammation, fever, and antimicrobial proteins.
natural killer cells
The ______________ membranes are the first line of defense against entry of pathogens. The closely packed keratinized cells of the epidermis are a physical barrier to invasion. Mucous membranes have mucus that traps microbes and cilia that sweep microbes away from the lungs. Tears, ___________, urine, and vaginal secretions flush microbes from the body. Defecation and ________ expel microbes. The ___________ of gastric juice and vaginal secretions discourages bacterial growth.
skin and mucous
saliva
vomiting
acidity
Pathogens that get past the first line of defense are attacked by internal defenses, they are?
Natural killer cells and phagocytes attack and kill pathogens and defective cells in the body.
Inflammation aids disposal of microbes, toxins, or foreign material at the site of an injury and prepares the site for ___________________.
tissue repair
How does fever help the immune response?
Fever intensifies the antiviral effects of interferons,
inhibits growth of some microbes,
and speeds up body reactions that aid repair.
Antimicrobial proteins (_______________ and complement) inhibit microbial growth.
Interferons
What does the complement system do?
The complement system destroys microbes through phagocytosis, cytolysis, and inflammation.
The complement system is a group of proteins that “complement” immune responses and help clear _______________ from the body. Once activated, complement proteins bring about phagocytosis, _____________, and inflammation.
antigens
cytolysis
What is adaptive immunity?
Adaptive immunity involves the production of a specific lymphocyte or antibody against a specific antigen.
What are antigens?
Antigens are foreign substances that produce an immune response. Adaptive immunity has specificity for particular antigens and memory of previous antigens.
Where do B cells and T cells arise from?
B cells and T cells arise from stem cells in red bone marrow. B cells mature in red bone marrow; T cells mature in the thymus.
How do B & T cells help build immunity and strength to fight?
B cells and T cells become immunocompetent, capable of carrying out adaptive immune responses by inserting antigen receptors into their plasma membranes. Antigen receptors are molecules that are capable of recognizing specific antigens.
In _______________ immunity, cytotoxic T cells directly attack invading antigens and are effective against intracellular pathogens, cancer cells, and transplanted tissues. In ____________y mediated immunity, B cells become plasma cells that secrete antibodies used against extracellular pathogens.
cell - mediated
anti -body
What is Clonal selection ?
Clonal selection is the process by which a lymphocyte divides and differentiates into a clone of cells that can recognize the same specific antigen as the original lymphocyte.
What cells are produced in Clonal selection?
The clone includes effector cells and memory cells. Effector cells destroy or inactivate the antigen.
Memory cells do not actively participate in the initial immune response, but if the antigen reappears in the body in the future, memory cells quickly divide and differentiate into more effector and memory cells.
What are Self -antigens?
called major histocompatibility complex (MHC) molecules are unique to each person’s body cells. All cells except red blood cells display MHC molecules.
Antigen presenting cells process ____________ antigens (present outside body cells), which results in an antigen–MHC complex being displayed on the cell’s plasma membrane. The exogenous antigen–MHC complexes trigger adaptive immune responses in T cells.
exogenous
________________ antigens (present inside body cells) bind with MHC molecules. The endogenous antigen–MHC complexes insert in the plasma membrane, which signals that the cell is infected.
Endogenous
What are Cytokines ?
Cytokines are small hormones that stimulate or inhibit many normal cell functions such as growth and differentiation. Other cytokines regulate immune responses.
A cell - mediated immune response begins with activation of a small number of_______________ by a specific antigen and ultimately results in elimination of the intruder.
T cells
During the activation process, T cell receptors recognize and bind to antigen fragments associated with ____________molecules on the surface of a body cell. Activation of T cells also requires ____________, usually by interleukin2. Once a T cell has been activated, it undergoes clonal selection
MHC
costimulation
Helper T cells display the ____________ and are activated by MHC molecules presented by an
APC. Once activated, helper T cells undergo clonal selection, then secrete several cytokines, most importantly ______________, which acts as a costimulator for other T cells, B cells, and natural killer cells.
CD4 protein
interleukin2
Cytotoxic T cells display the __________ and are activated by MHC molecules on the surfaces of body cells infected by microbes, ___________, and transplanted tissue cells. Once activated, cytotoxic T cells undergo clonal selection.
CD8 protein
tumor cells
Active cytotoxic T cells kill infected cells by releasing ______________, which cause target cell apoptosis (phagocytes then kill the released microbes); perforin, which causes target cell cytolysis; and granulysin, which enters the target cell to destroy microbes.
granzymes
Antibodies form antigen–antibody complexes with their complementary antigens, which disables antigens by blocking attachment of the antigen to body cells, _______________, agglutinating and precipitating antigen, activating complement, and enhancing _______________
immobilizing bacteria
phagocytosis
How does Immunological memory help the body respond?
Immunological memory results in a more intense secondary response to an antigen.
