Chapter 21: The Lymphatic and Immune Systems

________________ T cells attack foreign cells.

Cytotoxic

Which are types of lymphocyte?

-B cell -NK cell -T cell

Which are characteristics of a primary immune response?

-IgM antibodies are formed first -antibodies first appear 3-6 days after exposure, peaking at day 10 -it occurs with the first exposure to an antigen

Which cells induce cytolysis by secreting perforin?

-NK cells -Cytotoxic T cells

Match each type of immunity with the correct example.

-Natural active immunity = a person develops resistance to a virus picked up from a drinking fountain -Artificial active immunity = a person is given an attenuated smallpox virus and develops resistance -Natural passive immunity = a baby acquires resistance to a virus through antibodies obtained through breast milk -Artificial passive immunity = an antibody is injected into a person who has been bitten by a snake; the antibody infers resistance

Match each class of hypersensitivity with its description.

-Type I = acute -Type II = antibody dependent cytotoxicity -Type III = immune complex -Type IV = delayed

What are possible causes for a lack of self tolerance?

-abnormal exposure to self antigens -cross reactivity between similar antigens -alteration of self antigens

Which describe lysozyme?

-an enzyme -found in saliva, tears and other body fluids -capable of destroying bacteria

Which are characteristics of a secondary immune response?

-antibodies first appear within hours, peaking at day 3 -it occurs after the second and subsequent exposures to an antigen -IgG antibodies are formed first

Which cells release inflammatory mediators such as histamine, leukotrienes and heparin?

-basophils -mast cells

What are the beneficial effects of fever?

-elevated metabolic rate -inhibition of bacterial and viral replication -elevated interferon activity

What are three inflammatory mediators released by basophils and mast cells?

-heparin -leukotriene -histamine

The function of complement is to induce pathogen destruction by several mechanisms. Identify four of these.

-immune clearance -phagocytosis of pathogens -cytolysis -inflammation

Antibodies function to render antigens harmless by which of the following?

-precipitation -neutralization -agglutination -complement fixation

List the mechanisms used by eosinophils to kill parasites.

-produce hydrogen peroxide -produce superoxide anion

What are the cardinal signs of inflammation?

-redness -heat -pain -swelling

What are possible routes by which HIV can be contracted?

-semen -breast milk -blood -vaginal secretions

The great diversity in the specificity of antibody molecules is produced through which processes?

-somatic hypermutation -somatic recombination

To function properly, T cells must have which two traits?

-the ability to recognize self MHC proteins -a lack of reactivity to self peptide fragments

Which features of skin offer immunoprotection?

-the presence of defensins -the presence of a continuous barrier to the external environment -the presence of lactic acid

Why do memory T cells allow for a faster immune response when the body is exposed to the same antigen again?

-there are more of them -there are fewer steps to activation

Which describe allergens?

-they are environmental antigens -they can occur in mold, dust and pollen -they induce allergies

Which describes a clonal population of T cells?

-they react to the same antigen -they are self-tolerant -they are identical

Place the events of the humoral response in order.

1. Immunocompetent B cells bind to an antigen 2. A B cell internalizes an antigen and displays it on MHC-II proteins to TH cells 3. TH cells secrete interleukins which activate the B cell 4. The B cell undergoes clonal selection 5. B cells differentiate into plasma cells and memory cells 6. Plasma cells produce and secrete antibodies

Humoral immunity is mediated by ______ lymphocytes.

B

NK cells induce apoptosis in virally infected cells by secreting which protein-degrading enzymes?

granzymes

Platelets and endothelial cells secrete platelet-derived __________________ factor, which stimulates the synthesis of collagen and multiplication of fibroblasts.

growth

Name the type of molecule that is too small to be antigenic by itself, but can induce an immune response when bound to a larger molecule.

hapten

Name the chemical secreted by basophils and mast cells that stimulates vasodilation.

histamine

B cells are the primary cell of _______________ immunity and T cells are the primary cell of _______________ immunity.

humoral; cell-mediated

The connective tissue of skin and mucous membranes produces __________________ acid, a viscous gel that inhibits the migration of microbes.

hyaluronic

The _________________, part of the brain, regulates and maintains body temperature. Its set point is elevated during fever.

hypothalamus

What is it called when mature T cells become capable of recognizing antigens presented by APCs?

immunocompetence

Name the tissue response to injury or trauma that serves to ward off a pathogen and promote tissue repair.

inflammation

Which protein inhibits the viral infection of neighboring cells?

interferon

The organic acid that may be excreted in sweat and inhibits microbial growth is ________________ acid.

lactic

During the inflammatory response, leukocytes traveling through the blood adhere to the blood vessel walls by which process?

margination

The characteristic of immunity termed ____________________ describes how, when reexposed to the same pathogen, the body reacts so quickly that there is no noticeable illness.

memory

Which is a fixed macrophage in the central nervous system?

microglia

A(n) ____________________ migrates into the tissues where it transforms into a macrophage.

monocyte

A T cell which has undergone positive and negative selection but has not become activated by an antigen is said to be ______________.

naive

A _________________________ is a leukocyte that functions to nonspecifically destroy bacteria by means of phagocytosis, intracellular digestion and secretion of bactericidal chemicals.

neutrophil

______________________ are granulocytes with a multi-lobed nucleus that destroy bacteria by means of phagocytosis, intracellular digestion, and secretion of bactericidal chemicals.

neutrophils

In artificial ___________________ immunity, the body is injected with antibodies from another person or an animal.

passive

Organisms that cause disease, such as bacteria or fungi, are considered _____________________.

pathogens

____________________ cells secrete antibodies.

plasma

Name the external barrier that is coated with antimicrobial chemicals such as lactic acid, dermicidin and defensins.

skin

What is the third line of defense against pathogens?

specific defenses

Which characteristic describes how immunity is directed against a particular pathogen, and that immunity to one pathogen usually does not confer immunity to others?

specificity

Which T cell plays an integral role in both humoral and cell mediated immunity?

Helper T cell

Which virus that causes acquired immunodeficiency syndrome (AIDS)?

Human immunodeficiency virus (HIV)

Which type of immunity is mediated by B cells and the antibodies they secrete?

Humoral

MHC class _____ proteins occur on all nucleated somatic cells and may trigger a cytotoxic T cell response if displaying a viral protein.

I

What type of hypersensitivity reaction is anaphylaxis?

I

Class ______ MHC proteins occur only on APCs.

II

Name the proteins on the surface of APCs that function to present antigens to other cells.

MHC

Once a B cell binds an antigen, it phagocytizes it and displays antigen fragments on what molecules?

MHC-II proteins

___________________ T cells are descended from the cytotoxic T cells and are responsible for memory in cellular immunity.

Memory

Which T cell inhibits multiplication and cytokine secretion by other T cells and thus limits immune responses?

Regulatory T cell

A peripheral blood smear indicates that a patient lacks both B and T cells. This patient likely has which of the following?

Severe combined immunodeficiency (SCID)

_______________________ lymphocytes originate in the red bone marrow, then finish maturation in the thymus.

T

Cellular immunity is mediated mainly by ________ cells, while humoral immunity is mediated mainly by ________ cells.

T; B

True or False: Interleukins are a class of cytokines secreted by a variety of cells which function to promote the development and differentiation of T, B and hematopoietic cells.

True

What is an accumulation of pus in a tissue cavity called?

abscess

In natural __________________ immunity, the body makes its own antibodies or T cells against a pathogen.

active

When the body makes its own antibodies or T cells against a pathogen, it is exhibiting what type of immunity?

active

The type of defense that provides future protection against a pathogen is called __________________ immunity.

adaptive

The clumping of cells by antibodies is called _______________________.

agglutination

What is hypersensitivity?

an excessive and harmful reaction to antigens

A patient who is immunodeficient would have which of the following?

an underactive immune system

What does hyperemia result from?

vasodilation

Any large molecule capable of triggering an immune response is called a(n) _______________________.

antigen

Which cell phagocytizes an antigen and displays fragments of it on its surface?

antigen-presenting cell

Interferons, complement, defensins and granzymes are examples of which of the following?

antimicrobial proteins

What does the body's second line of defense against pathogens consist of?

antimicrobial proteins, leukocytes and macrophages

Aspirin, acetaminophen and ibuprofen reduce the synthesis of prostaglandins and are generally called what?

antipyretics

A mast cell is very similar to the type of leukocyte called a(n) _____________________. Both secrete histamine, heparin and other chemicals involved in inflammation.

basophil

Name the granulocyte with coarse cytoplasmic granules that produces heparin, histamine, and other chemicals involved in inflammation.

basophil

The process called _____________ selection is the formation of a clone of identical T cells programmed against the same epitope.

clonal

Identical cells produced by mitosis from a single parent cell are called ________________.

clones

Which globulins make powerful contributions to both nonspecific resistance and specific immunity?

complement

Which proteins found in blood are involved in the nonspecific defense against pathogens?

complement

What class of chemical agents do interleukins and interferons belong to?

cytokines

Which T cells attack and destroy target cells by secreting perforins and granzymes?

cytotoxic

Which of the following forms pus?

dead neutrophils and macrophages

What is the exocytosis of lysosomal contents by neutrophils called?

degranulation

Name the leukocyte that would help a patient combat a parasitic tapeworm infection.

eosinophil

An individual with a parasitic infection would likely have which of the following?

eosinophilia

A patient in anaphylactic shock will likely be administered ______________________ to induce bronchodilation, increase cardiac output and restore blood pressure.

epinephrine

The region of the antigen which stimulates an immune response is the ____________________.

epitope

What does the first line of defense against pathogens consist of?

external barriers

___________________ is an abnormal elevation in body temperature not due to failed thermoregulation.

fever