Lesson 14: 20.15-20.22

Inappropriate or excessive immune responses to antigens are

allergies

Autoantibodies are

directed against the body's own antigens.

When large numbers of antibodies encounter their antigenic targets, they interact to form a three-dimensional structure known as a(n)

immune complex

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

neutralization

During a primary response to antigen exposure, all of the following occur except

neutrophils invade the surrounding areas, releasing chemotactic substances.

The cells responsible for producing antibody molecules are ________ cells.

plasma

Which cells produce antibodies?

plasma cells

T cells release cytokines to stimulate the activation of

B cells

The cells responsible for antibody-mediated immunity are the ________ cells.

B cells

When an antigen is bound to a Class II MHC protein, it can activate a(n)_______ cell.

CD4 T

Lymphocytes that destroy foreign cells or virus-infected cells are ________ cells.

Cytotoxic T cells

Identify the three major types of T cells activated by class I MHC proteins.

Cytotoxic T cells, regulatory T cells, and memory Tc cells.

Class II MHC molecules are found only on which of the following? A) all body cells with a nucleus B) red blood cells C) granulocytes and microphages D) lymphocytes and antigen-presenting cells E) liver cells and macrophages in the spleen

D) lymphocytes and antigen-presenting cells

Which chemicals to mast cells and basophils release when stimulated in an allergic reaction?

Histamines, leukotrienes, and other chemicals that cause inflammation.

Immunoglobulins that attach to and sensitize mast cells and basophils are

IgE

Rheumatoid arthritis:

Is an autoimmune disorder

Cytotoxic T cells attack target cells by doing what?

activating genes that trigger apoptosis

In viral infections, what occurs after helper T cells are activated?

activation of B cells

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

anaphylactic shock

Which cells are involved in inflammation?

basophils and mast cells