Columns Lymph - Sheet1 Flashcards
Immunity is the ability of the ______ to defend itself against specific invading agents.
immune system
______ are substances recognized as foreign by the immune responses.
Antigens
The distinguishing properties of immunity are ______ and ______.
specificity, memory
Both T cells and B cells derive from ______ in bone marrow.
stem cells
T cells complete their development, becoming immunocompetent, in ______.
the thymus
B cells complete their development, becoming immunocompetent, in ______.
bone marrow
______ develop from pre-T cells that migrate to the thymus where they become immunocompetent under the influence of thymic hormones.
T cells
Before T cells leave the thymus or B cells leave bone marrow, they acquire several distinctive surface proteins; some function as ______.
antigen receptors
Cell-mediated immunity refers to destruction of antigens by ______.
T cells
Cell-mediated immunity is particularly effective against ______ pathogens, such as fungi, parasites, and viruses; some cancer cells; and foreign tissue transplants.
intracellular
Antibody-mediated (humoral) immunity refers to destruction of antigens by ______.
B cells
Antibody-mediated immunity works mainly against antigens dissolved in body ______ and extracellular pathogens.
fluids
A pathogen often provokes ______ types of immune response.
both
Clonal selection is the process by which an immune cell ______ and differentiates in response to a specific antigen.
proliferates
Two major types of cells result from clonal selection: 1) ______ cells; and 2) memory cells.
effector
Effector cells are the cells that actually do the work to destroy the antigen and include: ______ T cells, helper T cells, and plasma cells.
cytotoxic
Memory cells, with ______ life spans, provide a faster invasion response by proliferating and differentiating into effector cells.
long
Antigens are ______ substances that are recognized as foreign by antigen receptors when introduced into the body.
immunogenic
An antigen that gets past the nonspecific defenses can get into lymphatic tissue by entering an injured ______ and being carried to the spleen.
blood vessel
Antigens are large, complex molecules. They are most often ______, but sometimes are nucleoproteins, lipoproteins, glycoproteins, and certain large polysaccharides.
proteins
Specific portions of antigen molecules, called ______, trigger immune responses.
epitopes
Antigen receptors exhibit great diversity due to ______.
genetic recombination
Major histocompatibility complex (MHC) antigens (also called human leukocyte antigens, or HLA) are ______ to each person’s body cells.
unique
All cells except ______ display MHC class I antigens.
red blood cells
Some cells also display MHC class II antigens, particularly ______ cells.
antigen-presenting
For an immune response to occur, B and T cells must recognize that a foreign antigen is ______.
present
B cells can recognize and bind to antigens in ______.
lymph, blood, or interstitial fluid
T cells can only recognize fragments of antigenic proteins that first have been processed and presented in association with ______ self-antigens.
MHC
Processing of exogenous antigens is carried out by cells called ______.
antigen-presenting cells (APCs)
APCs include macrophages, B cells, and ______ cells.
dendritic
Most cells of the body can process and present ______ antigens, antigens that were synthesized in a body cell.
endogenous
Cytokines are small protein ______ needed for many normal cell functions.
hormones
In a cell-mediated immune response, an antigen is ______, a small number of specific T cells proliferate and differentiate into a clone of effector cells.
recognized
T cell receptors recognize antigen fragments associated with MHC molecules on the ______ of a body cell.
surface
Proliferation of T cells requires ______ by cytokines such as interleukin-1 (IL-1) and interleukin-2 (IL-2).
co-stimulation
