Mastering Bio Immune System

What is the role of mast cells in the inflammatory response?

They release chemicals that dilate blood vessels at the wound site....Mast cells release histamine, which causes dilation of arterioles and leads to increased blood flow to the injured tissue.

When comparing viruses and bacteria, which one of the following statements is CORRECT?

Viruses and bacteria both contain genetic material.

Which of the following statements about viruses is true?

Viruses require a host cell in which to reproduce.

Which of the following increases the likelihood of successful organ transplant?

administration of immunosuppressive drugs matching the MHC tissue antigens matching the ABO blood group antigens

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

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

Structures that precipitate antigens, promote lysis, attract phagocytes, and neutralize toxins are called ________.

antibodies....Antibodies defend the system by precipitating antigens, promoting lysis, attracting phagocytes, and neutralizing toxins.

In which of the following choices is the cell correctly matched with its function?

basophil: secretes histamine

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

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

Lymphatic vessels are similar to veins in that they both __________.

contain one-way valves to prevent the backflow of fluid.... Both veins and lymphatic vessels contain one-way valves.

Activation of a B cell leads to all of the following, EXCEPT __________.

destruction of cytokines....Cytokines are part of the body's defense in cell-mediated immunity.

Lymph nodes filter the blood and remove bacteria and other invading microorganisms that may have entered the blood stream.

false

Viral infections can usually be treated with antibiotics.

false

True or false. When you suffer an injury, white blood cells near the injury site initiate the inflammatory response.

false..... The injured tissue releases chemicals that begin the inflammatory response.

The direct cause of the heat generated by a wound or local infection is ________.

histamine, which causes the smooth muscle cells of the arterioles to relax; this leads to a cascade of events causing the tissue to become hot....Histamine, released by the mast cells, causes the smooth muscle cells of the arterioles to relax and ultimately leads to the heat apparent in the infected tissue.

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.

The primary immune response is __________.

less effective than the secondary immune response

Which of these cells is a phagocytic leukocyte that can engulf a foreign bacterium?

macrophage...Macrophages are phagocytic leukocytes.

Which of the following types of cell can ingest pathogens?

macrophages....Macrophages are phagocytic cells that can ingest pathogens; they can also present antigens to helper T cells.

Fever is caused when __________ release __________.

macrophages; pyrogens...Pyrogens are produced by macrophages and do produce fever.

Which of these cells is responsible for the rapidity of the secondary immune response?

memory cells....responsible for the rapidity of the secondary immune response and for long-term immunity.

What type(s) of cell(s) can helper T cells become?

memory helper T cells and effector helper T cells...Helper T cells can develop into both memory helper T cells and effector helper T cells.

Which of the following is NOT a major factor affecting the danger of a pathogen?

mode of metabolism....While this can affect the danger of a pathogen, it is not a major factor.

The role of cytotoxic T cells is the secretion of _____, which plays a role in the _____ immune response.

perforin ... cell-mediated.......Perforin causes the lysis of pathogen-infected body cells; it is a component of the cell-mediated immune response.

What cells make antibodies?

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

B cells that have been stimulated by interleukin-2 develop into _____.

plasma cells....develop from B cells that have been stimulated by the interleukin-2 secreted by helper T cells.

Which of these cells produce and secrete antibodies?

plasma cells...are clones of antibody-secreting B cells.

Which one of the following diseases is caused by a virus?

rabies

The spleen __________.

removes damaged red blood cells from circulation...The spleen destroys old and damaged red blood cells.

The following are steps in phagocytosis: (1) Bacterium is digested by lysosomal enzymes; (2) phagocyte approaches bacterium; (3) phagocytic vesicle fuses with lysosome; and (4) phagocyte engulfs bacterium, forming a phagocytic vesicle. In which order do these steps occur?

2-4-3-1

There are four bacteria in an egg salad that is left out at room temperature. After two hours, how many bacteria will be in the egg salad?

256....The bacteria would double 6 times in 2 hours, so the total number of bacteria in the egg salad would be 256.

Which of the following does NOT belong with the others?

Anaphylactic shock

Clonal selection is the division of _____ that have been stimulated by binding to an antigen, which results in the production of cloned _____.

B cells ... plasma cells and memory cells...The antigen-selected proliferation of B cells produces clones of plasma cells and memory cells.

In which of the following ways are bacterial cells similar to human cells?

Bacterial cells use ATP to fuel cellular activities.

Autoimmune disorders occur when __________.

the immune system fails to recognize "self" cells...Autoimmune disorders occur when the body fails to recognize "self" cells and attacks its own cells as foreign.

Which structure helps bacteria to attach within the tissues that they will infect?

Capsule....The gelatinous capsule that covers some bacteria helps them attach to the tissues that they will infect.

What is the final step in the cell-mediated response to a viral infection?

Cytotoxic T cells punch holes in the membranes of infected host cells....This event causes infected host cells to burst and die and prevents the virus from spreading to other cells.

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

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

Which of the following statements about HIV is true?

HIV specifically impairs the cell-mediated immune response.

_____ interact with the antigen-class II MHC complex presented by macrophages.

Helper T cells....Specific helper T cells recognize specific antigen-class II MHC complexes. The result of this is an activated helper T cell that stimulates both humoral and cell-mediated immune responses.

The pain associated with the inflammatory response is the direct result of ________.

the swelling of the tissue and the chemicals released from certain cells....The swelling and the chemicals may both stimulate surrounding sensory neurons and this brings about pain.

Inflamed tissue turns red because ________.

there is an increased blood flow to the injured tissues due to dilation of arterioles in the injured area.....The localized increase in blood flow is often seen as redness surrounding the injured tissue as histamine relaxes the smooth muscle in the vessels.

True or false. Bacteria reproduce by an asexual process in which one parent cell gives rise to identical daughter cells.

true....Bacteria reproduce by binary fission, which is an asexual process in which one parent cell splits in two to give rise to identical daughter cells.

Specific defense mechanisms differ from nonspecific defense mechanisms in that only specific mechanisms __________.

utilize B cells and T cells...The action of B cells and T cells is triggered only by a specific antigen.

Which of the following statements about plasma cells is FALSE?

Plasma cells are part of the MHC system....This statement is false. Plasma cells are effector B cells and not part of the MHC system. Therefore, this is the correct answer.

Which one of the following types of T cells is a critical component of the immune system because it stimulates and enhances the activity of other components of the immune system?

T helper cell

What do lysozyme, keratin, and mucus have in common?

They are all part of the first line of defense....All participate in preventing a pathogen from entering the body.