Immunity

Select all that are true regarding immunologic memory.

(X) Antigen challenge is required for generation of memory cells. (X) Upon first exposure, symptoms of sickness may develop. (X) Upon second exposure, the antigen is often destroyed before symptoms develop. (X) Memory B-lymphocytes and T-lymphocytes are responsible for immunologic memory.

Select all that are infectious agents.

(X) Bacteria (X) Fungi (X) Viruses (X) Parasites

Check all that occur during inflammation.

(X) Chemical mediators cause vasodilation ( ) Blood flow is decreased to the area ( ) Vascular permeability is decreased (X) Fibrin walls off the infected area (X) Complement attracts phagocytes to the area

Which of the following properties distinguishes specific immunity from nonspecific defense? Check all that apply.

(X) Immunity is directed against a particular pathogen. (X) The body reacts quickly to a pathogen to which it was previously exposed. ( ) Specific immunity utilizes broad-range barriers like skin and mucous membranes. (X) When reexposed to a pathogen, there are usually no noticeable signs or symptoms of disease from that pathogen. ( ) Specific immunity utilizes immune surveillance.

Why might it be beneficial to allow a mild fever to continue? Select all that apply.

(X) Replication of bacteria and viruses is slowed. ( ) Interferon activity is depressed. (X) It stimulates migration of immune cells into the tissues. (X) It accelerates tissue repair.

An immune cell is observed to present antigen to naive helper and cytotoxic T-lymphocytes. Using this information, select all that apply

(X) The cell is an antigen-presenting cell. (X) The cell may be a macrophage. (X) The cell may be a dendritic cell. (X) The cell may be a B-lymphocyte.

Select all that are true regarding cytokines.

(X) Their actions are similar to hormones. ( ) They circulate in the blood for years. (X) They regulate immune cells. (X) They include interleukins.

Select all that are true. After leaving the thymus, T-lymphocytes

(X) are naïve. (X) are immunocompetent. ( ) have previously bound at least one foreign antigen. ( ) contain both CD4 and CD8 proteins.

Cytotoxic T-lymphocytes

Cause cell lysis

Which of the following statements accurately describes the difference between cellular and humoral immunity?

Cellular immunity directly attacks pathogens and infected cells, while humoral immunity releases antibodies to do so.

Which of the following is not an antigen-presenting cell?

Cytotoxic T-lymphocytes

(T/F) Fragments of foreign proteins that can initiate an immune response are referred to as antibodies.

False

A secondary response is slower than a primary response.

False

The likelihood of a reaction to a hapten decreases with subsequent exposure.

False

Typically, a lymphocyte will encounter its first exposure to a foreign antigen in the

secondary lymphatic structures.

Leukotrienes

Group of lipids: cause smooth muscle contraction

Prostaglandins

Group of lipids: cause smooth muscle relaxation and vasodilation

In the blood, the antibody in most abundance is

IgG

A sample of blood from a mismatched transfusion is observed under the microscope. Many large clumps of erythrocytes are observed. Which is the antibody responsible for this?

IgM

Foreign antigen description

Introduced from outside the body

Chemical mediator

Kill microorganisms, promote inflammation

Surface chemicals

Lysozymes; prevent microbial growth or kill microorganisms

Self-antigen description

Molecules produced by the body

Foreign antigen example

Pollen

Kinins

Polypeptides derived from plasma proteins; cause vasodilation

Physical barrier

Prevent microorganisms from entering the body

Interferons

Proteins produced by cells; interfere with virus production

Memory T-lymphocytes

Provide a secondary response and long-lasting immunity

If negative selection of T-lymphoctyes in the thymus never occurred, what would likely happen?

T-lymphocytes would bind self-antigens.

(T/F) A normal, healthy cell only displays self-antigens with the MHC class I molecules.

True

(T/F) High fever is dangerous because proteins may denature and metabolic pathways may change.

True

A primary response occurs when B-lymphocytes are first activated by an antigen.

True

HIV, a virus that destroys helper T-lymphocytes, is damaging to the immune system because of the central role helper T-lymphocytes play in a normal effector response.

True

Haptens bound to a protein or other carrier can stimulate an adaptive immune response.

True

Haptens bound to a protein or other carrier can stimulate an allergic response.

True

In a primary response, B-lymphocytes form plasma cells and memory cells.

True

In a secondary response, memory cells form plasma cells and more memory cells.

True

Interferons are made and released by host cells in response to the presence of viruses, bacteria, parasites or tumor cells.

True

Many different antibodies can be made against a single antigen.

True

Penicillin is an example of a hapten.

True

Tumor necrosis factor is a class of cytokine that destroys tumor cells.

True

When an antibody binds an antigen, it is binding with its

Variable region

Immune complexes consist of

antigen plus antibody.

Receiving antivenom to treat a snake bite is an example of ___________ immunity.

artificially acquired passive

Cytotoxic T-lymphocytes attack

cells that display foreign proteins on their surface.

A patient has a parasitic infection. Upon examination of a blood sample under the microscope, an abundance of granuloctyes are present. These are likely

eosinophils

Histamine released by mast cells leads to all of the following symptoms except

high fever

In ________ immunity, the body's reaction to foreign substances is the same regardless of the pathogen, but in _________ immunity, the body's reaction to foreign substances is specific to the particular pathogen present.

innate, adaptive

Under an electron microscope, an infectious agent is identified that is not cellular. This must be a

virus

When interferon attaches to a cell,

virus can enter the cell but cannot replicate.

During the inflammatory response ______ degranulate and release ________.

mast cells; histamine

If someone is infected with a virus, resulting in activated and memory B-lymphoctes and T-lymphoctes, they are exhibiting ____________ immunity.

Active

In IgE mediated hypersensitivity, all of the following are needed except

neutrophils

Histamines

Amine released from basophils, platelets, and mast cells; cause vasodilation

An antigen presenting cell presents antigen to a helper T-lymphocyte

on its surface on a class II MHC.

Cytotoxic T-lymphocytes produce a substance called _______, which creates holes in the cell membranes of target cells.

perforin

Antigen presentation requires the physical attachment of antigen to a specialized transmembrane __________ called MHC.

protein