Chapter 24 - The Body's Defenses

Question 0

_________ are proteins produced by virus-infected body cells that help other cells resist viruses.

Answer 0

Interferons

Question 1

Why are the first and second lines of defense called “nonspecific defenses”?

Answer 1

Because they do not distinguish one infectious microbe from another.

Question 2

Your body’s system of defenses against infectious diseases

Answer 2

Immune system

Question 3

Disease-causing viruses and microorganisms

Answer 3

Pathogens

Question 4

Name the two innate defenses

Answer 4

External Barriers and Internal Protections

Question 5

Name the third line of defense

Answer 5

Adaptive defense

Question 6

Why are adaptive defenses also known as acquired defenses?

Answer 6

Because they must be activated by exposure to specific invaders

Question 7

T or F?

Only vertebrates have adaptive defenses.

Answer 7

True

Question 8

______ defenses are the only defenses that prevent infection.

Answer 8

External barriers

Question 9

Name three external innate defenses.

Answer 9

Skin, secretions, mucous membranes

Question 10

Name four internal innate defenses.

Answer 10

• Phagocytic Cells
• Natural Killer Cells
• Defensive Proteins
• Inflammatory Response

Question 11

Name the two white blood cells that contribute to your internal innate defenses.

Answer 11

Phagocytic cells (“cellular eating”) and natural killer (NK) cells.

Question 12

Which white blood cell can recognize virus-infected or cancerous body cells and release chemicals that kill the diseased cells?

Answer 12

Natural Killer (NK) Cells

Question 13

Virus-infected cells 1) make and release interferons that 2) bind to plasma membrane receptors on nearby uninflected cells. This binding stimulates the healthy cells to 3) produce proteins that inhibit viral reproduction

Answer 13

Yes

Question 14

Name two defense proteins

Answer 14

• Interferons

- Complement Proteins

Question 15

Lymphocytes originate from the stem cells in the bone marrow

Answer 15

True

Question 16

Two types of lymphocytes

Answer 16

B cells and T cells

Question 17

A type of lymphocyte that matured in the bone marrow and later produces antibodies; responsible for the humoral immune response.

Answer 17

B cell (B for Bone marrow).

Question 18

A type of lymphocyte that matures in the thymus and is responsible for the cell-mediated immune response.

Answer 18

T cell (T for Thymus)

Question 19

Any molecule that elicits a response from a lymphocyte.

Answer 19

Antigen.

Question 20

A protein that is secreted by a B cell and attached to a specific kind of antigen, helping counter its effects.

Answer 20

Antibody.

Question 21

Once vaccinated, you have had a primary exposure to specific antigens. If you encounter these antigens again, your body will mount a rapid immune response. The cells that account for this rapid secondary response are called _______. The process that produces these long-lived cells is called _______.

Answer 21

Memory cells, clonal selection

Question 22

A baby has been born with an immunodeficiency disease. In trying to diagnose the problem, physicians discover that the child is not producing any antibodies. It is most likely that this child is missing what kind of cells?

Answer 22

B cells

Question 23

Name the cell most commonly attacked by HIV

Answer 23

Helper T cell

Question 24

Name the defensive cell that initiates the secondary immune response

Answer 24

Memory cell

Question 25

Name the defensive cell that attacks infected body cells.

Answer 25

Cytotoxic T cells

Question 26

Name the defensive cell that carried out the humoral immune response

Answer 26

B cell

Question 27

Name the white blood cell that engulfs cells or molecules

Answer 27

Phagocytic cell

Question 28

General name for B or T cells.

Answer 28

Lymphocyte

Question 29

__________ is a disease that is caused when: a. cholesterol and other substances accumulate in the walls of blood vessels, narrowing the blood flow passages and b. making it more likely that blood vessels will be plugged by a blood clot.

Answer 29

Atherosclerosis

Question 30

T or F? The leading cause of death in the U.S. is heart attacks (killing over 1 million people per year.

Answer 30

True

Question 31

T or F? Sweat, saliva, and tears contain antimicrobial chemicals such as lysozyme, an enzyme that disrupts the cell walls of bacteria

Answer 31

True

Question 32

Name three groups of nonspecific chemical defenses.

Answer 32

1) Sweat, saliva, and tears - contain lysozyme that disrupts the cell walls of bacteria 2) oils and glands - make skin inhospitable to micro organisms 3) stomach acids - kill most of the bacteria swallowed

Question 33

The flushing of open systems also protects the body from infection. Name three

Answer 33

1) Tears 2) Urine 3) Swallowing (flushes bacteria into the highly acidic stomach) or vomiting (rapidly expels harmful substances)

Question 34

__________ causes nearby blood vessels to dilate and leak fluid into the wounded tissue, causing it to swell. The swelling helps the tissue to heal by diluting toxins, immobilizing the area, and delivering platelets and clotting proteins to promote scabbing

Answer 34

Histamine

Question 35

T or F The pus that often fills an infected injury consists of dead white blood cells, fluid that leaked from capillaries, and other tissue debris.

Answer 35

True

Question 36

When your body is fighting an infection, _______ _______ fill with lymphocytes, causing the “swollen glands” in your neck and armpits.

Answer 36

lymph nodes

Question 37

T or F? Damaged cells also release prostaglandins, which: a. increase blood flow to the damaged area, causing the wound to turn red and warm, and b. stimulate nerves to send pain signals to the brain.

Answer 37

True

Question 38

__________ travel through the bloodstream to the hypothalamus, where they stimulate a fever, which may discourage bacterial growth.

Answer 38

Pyrogens

Question 39

T or F Cytotoxic T cells are the only T cells that actually kill other cells.

Answer 39

True

Question 40

__________ are abnormal sensitivities to antigens in the environment.

Answer 40

Allergies

Question 41

__________ _________ result when the immune system turns against the body’s own molecules

Answer 41

Autoimmune diseases

Question 42

In __________ _________ ____________, B cells make antibodies against many sorts of molecules, even histones and DNA released by the normal breakdown of body cells.

Answer 42

systemic lupus erythematosus (lupus)

Question 43

__________ __________ leads to damage and painful inflammation of the cartilage and bone of joints

Answer 43

Rheumatoid arthritis

Question 44

_______-_______ __________ results when the insulin-producing cells of the pancreas are the targets of autoimmune cell-mediated responses.

Answer 44

Insulin-dependent diabetes

Question 45

__________ __________, a type of cancer that affects the lymphocytes, can depress the immune system. Radiation therapy and drug treatments used against many cancers can have the same effect

Answer 45

Hodgkin’s disease