20.15-20.21

Immunoglobins that are primarily found in glandular secretions such as mucus, saliva, and tears are

IgA

Immunoglobins that attach to and sensitize mast cells and basophils are

IgE

Immunoglobins that are most abundant and are responsible for resistance against many viruses, bacteria, and bacterial toxins are

IgG

Which class of antibodies is secreted after an antigen is encountered?

IgM

___ cells enable the immune response to respond quickly and robustly if the same antigen is encountered a second time.

Memory

Inappropriate or excessive immune responses to antigens are

allergies

An allergen circulating in the blood stream affects mast cells throughout the body, dropping BP to dangerously low levels. This response is termed

anaphylactic shock

Destruction of antigens or cell lysis can be caused by all of the following except

antibody actions macrophages complement system cytotoxic T cells NOT helper T cells

___ will develop when the immune response mistakenly targets normal body cells and tissues

autoimmune disorders

HIV selectively infects

helper T cells

Infection with the HIV virus occurs through

intimate contact with an infected person's body fluids

Antibodies may bind to superficial sites on bacteria or other toxins, making the toxin incapable of attaching itself to a cell. This mechanism is called

neuralization

A test to measure the antibody level in a blood sample is called a

titer

T cells release cytokines to stimulate the activation of

B cells

Which statement regarding CD4 T cells is true?

Before they can initiate antibody mediated immunity, inactive CD4 T cells must be exposed to appropriate antigens on Class II MHC receptors

When an antigen is bound to a Class II MHC protein, it can activate an ___ cell.

CD4 T

Helper T cells do all of the following except

enhance cell mediated immunity activate sensitized B cells by costimulation enhance antibody mediated immunity secrete cytokines to stimulate production of plasma cells NOT destroy target cells using perforins

Cells that help regulate the antibody mediated immune response are ___ cells

helper T

Which mechanism results in a coating of antibodies and complement proteins that increases the effectiveness of phagocytosis?

opsonization

B cells prepare for activation by presenting an antigen bound to Class II MHC proteins in a process called

sensitization