Pearson Immune system

Which of the following provides a first line of defense against pathogens?

skin and mucous membranes

Which of the following is NOT a chemical barrier that helps prevent infections

the pH of the blood

Adaptive immune responses

third line of defense

Intact skin and mucous membranes

first line of defense

B and T lymphocytes

third line of defense

Inflammation

second line of defense

Fever

second line of defense

Which of the following is NOT a characteristic of Natural Killer (NK) cells?

NK cells recognize abnormal or cancer cells by a specific antigen on their cell membrane

Which of the following innate internal defenses work by interfering with viral replication?

interferons

How do phagocytes recognize foreign cells or

bacteria?

The phagocytes recognize molecules on pathogens not normally found on body cells.

Which of the innate defense mechanisms can lyse bacteria and mark cells for phagocytosis?

complement proteins

Which of the following can act as opsonins on bacteria, thus enhancing phagocytosis?

antibodies and complement proteins

Which leukocytes are sometimes referred to as "housekeeping" phagocytes because of their role in clearing (cleaning up) cell debris?

macrophages

What is the most important reason you should not try draining an abscess by pressing on it?

may spread infection to deeper tissue

Which of the following is/are the most specific internal defense against disease?

T cells

Which antimicrobial protein triggers

inflammation?

Which antimicrobial protein triggers

inflammation?

histamine

Discharge is one of the cardinal signs of

inflammation

False

Which of the following chemicals do NOT directly trigger inflammation?

antibodies

Which of the following phases involves white blood cells leaving capillaries?

diapedesis

Which type of chemical induces fever?

pyrogens

Which of the following is an effect of complement

activation?

opsonization

Which cells secrete histamines that trigger inflammatory pathways?

mast cells

Phagocytes are unable to adhere to bacteria that have external capsules concealing their membrane carbohydrates. Our immune system gets around this problem by coating such pathogens with

__________

opsonins

Virus-infected cells secrete interferons to "warn" other cells of the presence of virus and deny entry to

them.

True

Unless they are attached to protein carriers, haptens have immunogenicity but not reactivity.

False

Some immunocompetent cells will never encounter an antigen to which they can bind and therefore will never be called to service in our lifetime.

True

Which of the areas seen the figure must be occupied by T lymphocytes, at least for a while, but is NOT required for the production of B lymphocytes?

the thymus

How does a lymphocyte exhibit immunocompetence?

by being able to recognize their one specific antigen

Proliferation of lymphocytes occurs immediately after which of these events?

activation

Which of the following cells engulf antigens by phagocytosis and present fragments of them on their own surfaces for recognition?

dendritic cells

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

T cell

The nucleotide sequence within the genes that produce B cell receptor and antibodies are reshuffled by a process called somatic recombination. This produces the huge variability in antibody types

True

The antivenom used to treat a venomous snake bite is an antibody produced in an animal such as a horse. Suppose these antibodies are injected into a patient who has been bitten by a venomous snake. How would you classify the resulting humoral immunity?

passive immunity, artificially acquired

Which of the following should produce naturally acquired, active immunity?

recovering from the chicken pox

Why are children given vaccinations?

so that they will develop antibodies against various disease-causing pathogens

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.

Health workers working with diphtheria commonly receive a serum with antibodies against the pathogen. What type of immunity would this be?

passive, artificial immunity

Which molecules of the adaptive defense system provide humoral immunity by circulating freely in the blood and lymph, where they bind to extracellular antigens and inactivate them and mark them for destruction?

antibodies

Which of the following statements regarding the primary versus the secondary immune response is

true?

A primary response results when naïve lymphocytes are activated, while a secondary response is a result of activating memory cells.

Vaccines provide what type of

immunity?

artificially acquired active

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

antigen-presenting cells

Which class of MHC proteins presents exogenous

antigens?

class II MHC proteins

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

CD8

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

all nucleated cells

Which major class of lymphocytes become cytotoxic T cells?

CD8 cells

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

innate external defenses

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

What cells make antibodies?

plasma B cells

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

an antigenic determinant

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

humoral immunity

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

cell-mediated immunity (cellular immunity)

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

Cytotoxic T cells

What type of cell is the precursor to the helper T cell?

CD4 cell

Where does most exogenous antigen presentation take place?

in lymphoid tissues and organs

Which of the following statements does

not describe the adaptive immune response?

It occurs immediately after the body is challenged by foreign material.

Activated CD8 T cells become

__________.

cytotoxic T cells

What occurs if a naïve T cell binds to an antigen without receiving a co-stimulatory signal?

The T cell enters a state of anergy.

Perforins form complexes that penetrate the cell membrane and allow the passage of the apoptosis inducing protein granzyme to enter the targeted cell.

True

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

Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells.

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.

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 B cells

Correctly order the steps involved cellular

immunity:

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

2,4,1,3

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

Place the following steps of phagocytosis in the order that they

occur:

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

2,1,4,3,5

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

BCR and TCR

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

Which of the following statements is

true?

Adaptive defenses include both humoral and cellular immunity.

Which of the following are NOT correctly

matched?

immediate hypersensitivity: allergic contact dermatitis

Which of the following is NOT an event that can result in an autoimmune disease?

binding of a T cell to an antigen without receiving a co-stimulatory signal

Anaphylactic shock is a rare but severe allergic response that may occur if the allergen enters the blood stream.

True