Chapter 19 (Exam 4) Flashcards
____ is responsible for defending the body against both environmental hazards and internal threats.
Lymphoid system
The lymphocytes are most important in doing what?
Fighting infection
____ are produced and stored in lymph node organs, lymphoid nodules, the spleen, tonsils, and the thymus.
Lymphocytes
The lymph, lymph nodes, the spleen, and lymphatic vessels make up what system?
Lymphoid System
Most of the lymph returns to the venous circulation by what?
Thoracic duct
T is to ________ as B is to ________.
Thymus-dependent
Bone marrow-derived
Lymphocytes respond to what?
Antigens
Which lymphocytes migrate throughout the body, moving through peripheral tissues in search of abnormal cells?
NK cells
Which lymphocytes are responsible for antibody-mediated immunity?
B cells
Which cells are responsible for cell-mediated immunity?
Mature T cells
3 functions of the lymph nodes?
Remove debris and pathogens from the lymph.
Detect Pathogens
Monitor the contents of lymph.
How do lymphoid organs differ from lymphoid tissue?
Lymphoid organs are surrounded by a fibrous capsule and the tissues aren’t.
____are large lymphoid nodules that are located in the walls of the pharynx.
Tonsils
Stem cells that will form T cells develop in the ____.
Bone Marrow
____ produces T cells, reaches its greatest relative size before puberty, lies in the anterior mediastinum, and involutes after puberty.
Thymus gland
If the thymus shrank and stopped making thymosins, we would expect to see an immediate decrease in the number of?
T cells
Areas of the spleen that contain large aggregations of lymphocytes are known as?
White pulp
The first line of cellular defense against pathogens are the____?
Phagocytes
The skin, interferon, complement, and inflammation are all part of what defense?
Nonspecific defense
4 things that act as physical barriers to infection.
Body hair
Epithelium
Basement Membranes
Secretions
Various types of macrophages are derived from ____.
Monocytes
____ is a system of circulating proteins that assists antibodies in the destruction of pathogens.
Complement
____ are abundant, mobile, and quick to phagocytize cellular debris or invading bacteria?
Neutrophils
The cells that perform immunological surveillance are the ____ cells.
NK
The classic pathway of complement activation begins when the complement protein binds to what?
An antibody attached to an antigen.
____ are secreted by T cells and NK cells, and stimulate macrophage activity?
Gamma interferons
Which action of the complement system increases the degree of inflammation and accelerates blood flow to the region?
Release of histamine
____ is a nonspecific defense mechanism that increases the resistance of cells to viral infection and slows the spread of disease?
Interferons
3 effects of the compliment system.
Histamine release
Enhanced phagocytosis
Destruction of target cell plasma membranes
Stimulation of inflammation
____ increases blood flow and vascular permeability.
Histamine
4 effects of the increased blood flow and vascular permeability caused by histamine?
Swelling of the inflamed tissue.
Movement of defense proteins and cells into the interstitial space.
Heat of the inflamed tissue.
Redness of the inflamed tissue.
____ is triggered when mast cells release histamine and heparin.
Inflammatory response
The release of ____ by active macrophages would produce a fever
Endogenous pyrogen (or interleukin-1)
____ activate T cells, display antigen fragments, and process antigens.
Antigen-presenting cells
Newborns gain their immunity initially from where?
Antibodies passed across the placenta from the mother.
Immunity that is genetically determined and present at birth is called ________ immunity.
Innate
In an experimental situation, a rabbit is exposed to a viral antigen to which it makes antibodies. These antibodies are then purified and injected into a human with the same viral disease. This is an example of ____.
Passive immunity
Class II MHC molecules are found only on what?
Lymphocytes and antigen-presenting cells
Defense of the body against a particular pathogen is provided by ____.
Specific immunity
When an antigen is bound to a Class I MHC molecule, it can stimulate a ________ cell.
Cytotoxic T
When an antigen is bound to a Class II MHC protein, it can activate a ________ cell.
CD4 T
Cytotoxic T cells can attack target cells by activating genes that trigger what?
Apoptosis
Lymphocytes that destroy foreign cells or virus-infected cells are ________ cells.
Cytotoxic T
B cells are primarily activated by the activities of ____.
Helper T cells
The cells responsible for the production of circulating immunoglobulins are ________ cells.
Plasma
____ and ____ can only be activated by exposure to a specific antigen at a specific site in a plasma membrane.
T cells
B cells
____ activate sensitized B cells by costimulation, enhance cell-mediated immunity, secrete cytokines to stimulate production of plasma cells, and enhance antibody-mediated immunity.
Helper T cells
Immunoglobulins that attach to and sensitize mast cells and basophils are ____.
IgE
The most abundant type of antibody is ____.
IgG
Immunoglobulins, formed of five subunits, that are the first antibodies to be produced in response to infection, are ____.
IgM
Immunoglobulins that are primarily found in glandular secretions such as saliva and tears are ____.
IgA
In ____, the antigen binding site is formed by the variable segment of the light chain + the variable segment of the heavy chain.
IgG
____ can result in neutralization of the antigen, agglutination or precipitation, complement activation and opsonization.
Binding of an Antigen to an Antibody
Which mechanism results in a coating of antibodies and complement proteins that increases the effectiveness of phagocytosis?
Opsonization
Immunity that results from exposure to an antigen in the environment is called ________ immunity.
Naturally acquired active
Immunity that results from antibodies that pass the placenta from mother to fetus is called ________ immunity.
Naturally acquired passive
The production of ____ involves bone marrow, thymus tissue, and peripheral lymphoid tissues.
Lymphocytes
____ is the class of antibody first secreted in response to a new antigen.
IgM
The human immunodeficiency virus (HIV) that causes the disease known as AIDS selectively infects ____ cells
Helper T
