Chapter 21 Immune System Practice test

13.1 IgG 13.2 IgM 13.3 IgA 13.4 IgD 13.5 IgE A large, pentamer-shaped antibody B most abundant class of antibodies C antigen receptor found on B cells D antibody that mediates some allergies E dimeric antibody found in body secretions

13.1 B most abundant class of antibodies 13.2 A large, pentamer-shaped antibody 13.3 E dimeric antibody found in body secretions 13.4 C antigen receptor found on B cells 13.5 D antibody that mediates some allergies IgG is the most abundant class of antibodies in plasma. Additionally, IgG is the only class of antibodies that normally crosses the placenta to protect the baby in utero. IgM is a large, pentameric antibody. IgA is a dimeric antibody found in secretions such as mucus, saliva, tears, and breast milk. IgD is an antigen receptor found on B cells. IgE antibodies mediate allergy and protect the body from parasitic infections.

Which of the following types of cells is involved in adaptive immunity? neutrophils natural killer cells B cells macrophages

: B cells T cells and B cells are lymphocytes that are involved in the adaptive (also called specific) immune response. Macrophages, neutrophils, and natural killer cells (NK cells) are innate immune responders.

Which of the following is a characteristic of a secondary immune response? A secondary immune response lasts longer than a primary immune response. A secondary immune response produces as many antibodies as a primary immune response. A secondary immune response is slower than a primary immune response. A secondary immune response is started by naive lymphocytes, while a primary immune response is initiated by memory cells.

A secondary immune response lasts longer than a primary immune response. A primary immune response is initiated when naive lymphocytes are exposed to foreign antigens. Re-exposure to the same antigen provokes a secondary response, occurring faster because memory lymphocytes are activated. A secondary response also lasts longer and produces more—and more effective—antibodies than a primary response.

_____ are substances that can trigger the adaptive defenses and provoke an immune response. Antibodies Haptens Interleukins Antigens

Antigens Antigens are substances that can induce an adaptive immune defense and provoke an immune response. Antibodies can be made in response to foreign antigens. Haptens are not immunogenic unless they combine with other substances in the body; they are not able to independently provoke an immune response.

Which of the following is NOT a property of interferons (IFNs)? IFNs activate macrophages. IFNs have antiviral activity. IFNs stimulate B cells to produce antibodies. IFNs have an anticancer role.

IFNs stimulate B cells to produce antibodies. Interferons (IFNs) are a group of proteins that have antiviral effects. IFNs also activate macrophages and mobilize natural killer cells (NK cells) that act directly against malignant cells, giving IFNs an anticancer role.

_____ is the property of lymphocytes that prevents them from attacking the body's own cells. Self-tolerance Antigenicity Immunocompetence Immunological memory

Self-tolerance T cells are screened for self-tolerance in the thymus. B cells mature and are screened for self-tolerance in the bone marrow. Self-tolerance is what prevents lymphocytes from attacking the body's own cells. Without self-tolerance, a person develops autoimmune disorders.

A moderate fever is an example of an innate body defense. True False

True A moderate fever is indeed an innate body defense. It is a second line of defense.

The most common type of organ transplant is the __________. xenograft allograft autograft isograft

allograft The most common type of organ transplant is the allograft. Allografts are grafts transplanted from different individuals of the same species. Tissue transplanted from one part of the patient's body to another region of the body (autografts), and grafts that are genetically identical to the tissue of the patient (isografts), are highly successful. An example of an isograft would be a graft between identical twins. Xenografts are tissues that are transplanted from one species to another species (e.g., transplanting baboon tissue into a human).

Humoral immunity is provided by __________. complement proteins antibodies interferons T cells

antibodies Adaptive immunity is categorized as being either cellular or humoral. Humoral immunity is facilitated by antibodies, which are made by plasma cells (activated B cells). The chief orchestrators of cellular immunity are T cells.

MHC II proteins are found on __________. red blood cells helper T cells antigen-presenting cells cytotoxic T cells

antigen-presenting cells MHC II proteins are found on antigen-presenting cells (APCs). Red blood cells do not express type I or type II MHC proteins.

A vaccination works to establish __________. artificial active immunity artificial passive immunity natural active immunity natural passive immunity

artificial active immunity Naturally acquired immunity is a consequence of a viral or bacterial infection; artificially acquired immunity is a result of vaccination. Active immunity is acquired when antibodies are produced by one's own cells. In contrast, passive immunity occurs when antibodies come from another source, such as an immune human or animal donor.

Self-reactive B cells are eliminated in the __________. bone marrow spleen lymph nodes thymus

bone marrow T cells are screened for self-tolerance in the thymus. B cells mature in the bone marrow. Self-reactive B cells are eliminated in the bone marrow.

What is the second step of T cell activation? chemotaxis antigen binding anergy co-stimulation

co-stimulation In order for a T cell to be activated and to release interleukins to coordinate an immune response, the T cell must first bind to an antigen. It then receives a co-stimulatory signal. If a T cell binds to an antigen but does not receive a co-stimulatory signal, then the cell enters a state of anergy, or non-responsiveness

Which are correctly matched? B cells: suppress the immune response once the foreign antigen has been cleared from the body helper T cells: recognize virus-infected cells regulatory T cells: make antibodies cytotoxic T cells: activated by antigens bound to MHC I

cytotoxic T cells: activated by antigens bound to MHC I Cytotoxic T cells recognize and destroy virus-infected cells. To do this, cytotoxic T cells must recognize foreign antigens that are presented in the context of MHC I. Helper T cells are lymphocytes that manage or orchestrate an immune response, but they do not directly kill cells. Helper T cells are activated by antigens that are presented by antigen-presenting cells in the context of MHC II. Activated B cells are called plasma cells. Plasma cells make antibodies. Regulatory T cells dampen the immune response once the foreign antigen has been cleared from the body.

Which of the following is NOT a sign of inflammation? redness swelling pain fever

fever Redness, pain, heat, and swelling are the four cardinal signs of inflammation. It should be noted that the term heat refers to local heat, not the systemic rise in internal body temperature that characterizes a fever

Which of the following are MISMATCHED? B cells: can be activated to produce antibodies regulatory T cells: release inhibitory cytokines to dampen the immune response helper T cells: directly target and kill cancer cells cytotoxic T cells: carry out cellular immune responses

helper T cells: directly target and kill cancer cells T helper cells are lymphocytes that organize the cellular and humoral immune response branches of the immune system. They do not directly target or attack anything; rather, they organize the immune defenses. B cells carry out the humoral response. Upon activation, B cells become plasma cells that will produce antibodies. Cytotoxic T cells carry out cellular immune responses. They target and kill virus-infected cells as well as cancer cells. Regulatory T cells are able to release inhibitory cytokines to dampen the immune response once the foreign antigen has been cleared from the body.

The first step in inflammation is __________. swelling phagocyte mobilization vasodilation the release of inflammatory chemicals

the release of inflammatory chemicals Inflammation progresses as follows the stimulus of tissue injury: release of inflammatory chemicals, vascular changes (such as vasodilation and increased vessel permeability), phagocyte mobilization, and tissue repair (healing).