Chapter 21 Immune system mastering

A class I MHC protein presents an antigen. What type of cell is likely presenting and to what type of cell would it be presented?

Any nucleated cell would present antigens to a CD8 cell.

Place the following steps of phagocytosis in the order that they occur:

1. Dendritic cell engulfs Rhinovirus 2. Endosome fuses with lysozome 3. Digestion of the Rhinovirus 4. Epitopes are attached to MHC-II 5. MHC-II plus the attached epitope move to the outside of the dendritic cell

Which of the following describes a hapten?

A hapten is a foreign molecule that becomes immunogenic when combined with body proteins. -Haptens trigger adaptive defenses when combined with body proteins, making them appear foreign. Examples of haptens can be found in poison ivy, animal dander, and certain drugs.

Activated CD8 T cells become __________.

Activated CD8 T cells become cytotoxic T cells.

Which of the following statements is true?

Adaptive defenses include both humoral and cellular immunity.

What is meant by the clonal expansion of a B cell?

An activated B cell divides into cells that give rise to memory B cells and plasma cells.

Which pair of molecules do NOT directly interact with one another?

BCR and TCR -Both of these molecules interact with epitopes. BCRs interact with epitopes on the whole pathogen. TRCs interact with processed epitopes when presented on MHC-II.

Which of the following is NOT a typical sign of inflammation?

Bruising is a sign of internal hemorrhaging and injury, but bruising is not a typical part of the inflammatory response.

Which major class of lymphocytes become cytotoxic T cells?

CD8 cells become cytotoxic T cells.

Which of the following inflammatory chemicals is/are released by mast cells?

Histamine is one of the products produced by mast cells to moderate inflammation. It is also released by basophils, which are similar to mast cells but reside in the blood.

Which of the following best describes humoral immunity?

Humoral immunity refers to the presence of specific antibodies in the body fluids.

What protein can be released by infected cells to help protect cells that have not yet been infected?

Interferon is a small protein that can stimulate nearby healthy cells to defend themselves against viral infection.

What roles do memory B cells play when a patient is re-exposed to an antigen?

Memory B cells trigger a secondary immune response, which is faster, more prolonged, and more effective than the first immune response.

The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. What component of the immune system will protect her from getting the same cold again?

Memory cells to that specific virus are stored in the lymph nodes for many years. When the student comes into contact with this specific Rhinovirus, these memory cells quickly divide and differentiate into antibody-producing plasma cells. The antibodies will prevent the virus from reaching an infectious titer (number that causes infection).

Which of the following is NOT a property of mucous membranes?

Mucus contains macrophages that attack invading pathogens. -Mucus itself does not typically contain macrophages.

With what does our immune system coat pathogens to facilitate their capture and accelerate phagocytosis?

Opsonins are needed to provide a gripping point on some cells that have capsules or other defenses against adherence by phagocytes.

Which of the following is an effect of complement activation?

Opsonization -Complement proteins stimulate inflammation, serve as opsonins to aid in the phagocytosis of targeted antigens, and facilitate cytolysis.

Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells?

Recognition of infected host cell using its CD4 glycoprotein

Which of the following activate CD8 cells?

T cells bearing CD8 receptors are activated by cells presenting endogenous antigens on class I MHC proteins.

Which of the following is not an antigen-presenting cells (APC)?

T cells do not act as APCs. Quite the opposite, APCs present antigens to T cells.

Which antimicrobial protein triggers inflammation?

The complement cascade activates inflammation to destroy foreign substances in the body.

Which is a part of the innate immune defenses?

The skin is the first innate barrier that works to prevent entry of any pathogens into the body.

How is the adaptive third line of defense able to target specific pathogens?

The third line of defense responds to antigens on the pathogen.

How do cytotoxic cells directly attack pathogens?

They bind to the pathogen and secrete chemicals that induce apoptosis.

Which specific type of cell produces antibodies?

When activated by the presence of antigens, B lymphocytes proliferate into plasma cells. Plasma cells generate antigen-specific antibodies.

Which of the following types of cells display protein fragments produced by the cancer within them?

all nucleated body cells bring pieces of endogenous proteins to the surface to display on the MHC protein.

What is the name of the unique area (specific region) that a lymphocyte recognizes and binds to?

also called an epitope, the antigenic determinant is the specific part of an antigen that the antibody or lymphocyte antigenic determinant receptor binds to. Part E

Class II MHC proteins are found on which of the following cell types?

antigen-presenting cells

Cytotoxic T cells ________.

can directly attack and kill other cells of the body Submit

Natural killer (NK) cells ________.

can kill cancer cells before the adaptive immune system is activated

If a virus attacks a cell, which type of immunity would be activated?

cell-mediated immunity involves an intracellular pathogen such as a virus.

Class I MHC proteins are recognized by which of the following cell types (that are destined to become T cells)?

class I MHC proteins are recognized by CD8 cells

Which class of MHC proteins presents exogenous antigens?

class II MHC proteins

Cancer cells would be attacked by which of the following cells?

cytotoxic T cells attack cancer cells, since they are part of cell-mediated immunity.

Membrane attack complex (MAC) kills by ________.

disrupting the selective permeability of a bacteria's plasma membrane

T helper cells ________.

function in the adaptive immune system activation

Plasma cells ________.

have a great deal of rough endoplasmic reticulum reflecting the fact that they secrete a tremendous amount of protein (antibody)

What type of immunity can be transferred by bodily fluids from one person to another, thus conferring immunity to the recipient?

humoral immunity involves antibodies that can be transferred from one person to another.

Tears and mucus membranes would be a part of which defense system?

innate external defenses -innate external defenses (surface barriers) are the first line of defense and include tears, mucus membranes, and the skin.

Phagocytotic cells such as macrophages identify a variety of enemies by recognizing markers unique to pathogens. They would be classified as which type of defense system?

innate internal defenses -the macrophage recognizes many molecules found on pathogens that are not present on normal body cells.

What is/are the specific target(s) of interferons?

the membrane receptors on healthy cells -Interferon binds to membrane receptors in healthy cells and triggers a response inside the cell that leads to the production of chemicals that interfere with virus manufacture.

What cells make antibodies?

the plasma B cells make antibodies in response to specific antigens.

Correctly order the steps involved cellular immunity:

1. The Tc interacts with epitope presented by MHC-I on the dendritic cell 2. The helper T cell activates the Tc cell 3. The Tc recognizes the infected host cell 4. The Tc secretes perforin and granzyme, causing apoptosis

What is the role of complement in the innate immune response?

Activated complement proteins help amplify the immune response and lyse bacterial cells. These proteins also enhance the adaptive defenses.

Which of the following is NOT a step that ultimately leads to antibody production?

Activation of cytotoxic T cells by helper T cells

A person who has AIDS contracts rare and often life-threatening infections because their helper T cell count is so low. Which of the following components of the immune response still respond to antigen despite the low helper T cell count?

Clonal selection of B cells -B cells can still bind to antigen, which is the process of clonal selection. However, without a helper T cell, clonal expansion and antibody production will not occur.

What is the role of helper T cells in the adaptive immune response?

Helper T cells activate B cells that are displaying antigen, causing clonal expansion. Helper T cells also activate cytotoxic T cells, which will search for and destroy infected host cells.

Which lymphocytes act as the bridge between the cellular and humoral responses?

Helper T cells are lymphocytes that organize the cellular and humoral immune response branches of the immune system.

All of the following are true of the classical pathway of complement activation except one. Select the one answer that does NOT describe the classical pathway of complement activation.

It activates T helper cells by presenting antigen to them.

How do natural killer cells destroy invading pathogens?

Natural killer cells bind to target cells and secrete perforins and granzymes that degrade the target cell membrane. They also bind to membrane receptors that induce apoptosis.

Which of the following statements does NOT accurately describe a difference between the innate and adaptive defenses of the body?

The innate defenses of the body apply strictly to external pathogens, while adaptive defenses apply strictly to internal pathogens.

What characterizes flattening of neutrophils to squeeze between the endothelial cells of the capillary walls?

diapedesis -The flattening of neutrophils and subsequent movement through the vessel wall is in response to cell adhesion molecules on endothelial cells.