Chapter 43 Mastering: Immune System

Extracellular pathogens such as viruses and bacteria in body fluids are attacked by...

...antibodies.

An organism that lacks their thymus would...

...be unable to differentiate and mature T cells.

Helper T cells are part of...

...cell mediated immune response.

Innate immunity and adaptive are both...

...characteristics of all vertebrate animals.

T cells of the immune system include...

...cytotoxic and helper cells.

An antigen...

...is a molecule that evokes an immune response by a lymphocyte.

Macrophages are...

...large, phagocytic cells that can leave circulation and enter the tissues of the body.

Vaccination increases the number of...

...lymphocytes with receptors that can bind to the pathogen.

The primary reason for needing a new vaccine for influenza each year is that...

...mutation in the influenza virus is frequent.

Clonal selection and differentiation of B cells activated by antigen exposure leads to the production of...

...short-lived plasma cells that secrete antibodies for the antigen.

Vaccinations offer protection against future exposure to pathogens because it...

...triggers clonal expansion of lymphocytes.

Which of the following is the best definition of autoimmune disease?

A condition in which self molecules are treated as nonself (loss of self-tolerance)

Which response is triggered when bacteria enter the body through a small cut in the skin?

Activation of a group of proteins called complement.

Which statement best describes the concept of clonal selection?

An antigen can provoke production of high amounts of specific antibodies.

A patient has a high level of mast cell activity, dilation of blood vessels, and acute drop in blood pressure. Which condition is most consistent with these symptoms?

Anaphylactic shock immediately following exposure to an allergen.

What does the y-axis of this graph represent?

Antibody concentration in the blood.

Which secretion is not a barrier that prevents pathogens from entering the body?

Antigens Antigens are foreign molecules that initiate an immune response.

Which treatment is most appropriate for an individual complaining of watery, itchy eye and sneezing after being given a flower bouquet?

Antihistamines

Which statement best describes the difference between responses of effector B cells (plasma cells) and those cytotoxic T cells?

B cells secrete antibodies against a pathogen; cytotoxic T cells kill pathogen-infected host cells.

Is this statement supported or not supported by the graph? A third exposure to antigen X will produce an even stronger immune response than the second exposure did.

Cannot be determined from the graph.

True or false? The leukocytes of the innate system are B cells, macrophages, and neutrophils.

False The leukocytes of the innate immune system are mast cells, macrophages, and neutrophils.

B cells are stimulated to differentiate under which of the following conditions?

Helper T cells release cytokines.

Vertebrate immune cells, which are phagocytic, include which of the following? I) neutrophils II) macrophages III) dendritic cells IV) natural killer cells

I, II, and III

Which of the following are similarities between B cells and T cells? I) Both recognize antigens using immunoglobulin receptors. II) Both undergo clonal selection after encountering an antigen. III) Both maintain an immunological memory of previously encountered antigens.

II and III

A boy falls while riding his bike. A scrape on his hand almost immediately begins to bleed and becomes red, warm, and swollen. Which type of response is most consistent with these symptoms?

Inflammatory response A part of the innate system.

Which treatment could relieve the symptoms of an individual who has been bitten by a poisonous snake that has a fast-acting toxin?

Injection of antibodies to the toxin.

Acidity in human sweat is part of which type of immune system?

Innate immunity

Which statement is true about innate immunity?

Innate immunity is the first, and most general, mechanism of protection against pathogens.

Which answer describes an advantage of having a system of adaptive immunity?

It enables a rapid defense against an antigen that has been previously encountered.

How do cells involved in the innate response detect the presence of pathogens?

Leukocytes recognize unique molecules on pathogens.

Which of the following cells can engulf a pathogen?

Macrophages

Which of these is a characteristics of adaptive immunity but not innate immunity.\?

Memory

Is this statement supported or not supported by the graph? The primary immune response takes about 28 days to reach its peak.

Not supported

Is this statement supported or not supported by the graph? The primary immune response to antigen X occurred just as fast as the secondary immune response to antigen X.

Not supported

Which of the following events occurs first when a wound that breaks the skin has occurred?

Platelets release proteins that form clots and decrease bleeding.

Is this statement supported or not supported by the graph? The secondary immune response is stronger than the primary immune response.

Supported

What does the blue line on this graph represent?

The concentration of antibodies to antigen X.

What does the first blue peak (around day 17) represent?

The highest concentration of antibodies that occurs after the first exposure to antigen X.

Which statement best describes an account of immunological memory?

The observation that someone who had recovered from the plague could safely care for those newly diseased.

What does the second blue peak (around day 40) represent?

The peak of the secondary immune response to antigen X.

Which of the following protects both the eyes and the respiratory tract against infections?

The secretion of lysozyme onto their surfaces.

Benadryl is an antihistamine. Which of the following is most likely to occur if a person that was stung by a bee takes benadryl?

The site of injury will become less red and swollen.

Which option best describes why Jenner's use of cowpox virus as a vaccine against the smallpox virus was successful?

There are some epitopes (antigenic determinants) common to both pox viruses.

Which of the following statements best describes the role of mast cells in the inflammatory response?

They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream.

Mucus occurs in both the respiratory and digestive tracts. Which answer best describes the main immunological function of mucus?

To physically trap pathogens.

The site of inflammation may become swollen due to the increased numbers of cells and fluids at the site and painful due to signals from pain receptors.

True

You and your friend are equally exposed to a virus, bit over the next few days, only your friend acquired flu-like symptoms and was ill for almost a week before recovering. Which on of the following is a logical explanation for this?

You had an immunological memory of that virus.