Chp 16 and 17 A

Question 1

List the three lines of defenses a host organism uses to prevent invasion by pathogens.

Answer 1

1st line: physical or anatomical barriers:
- skin (acidity of skin
- Eyebrows and lashes
- nasal hair and ear hair
- ear wax
- stomach acid
- cilia in respiratory tract
- enzymes like lysozymes in tears of eyes

2nd line (innate):
- bloodstream
- lymphatic system
- Reticuloendothelial (RES) system
- Extracellular fluid

3rd line: acquired immunity

Question 2

Which defenses are considered innate?

Answer 2

first and second lines of defense

Question 3

What is an innate defense?

Answer 3

Defenses that are present at birth and provide nonspecific resistance to infection

Question 4

What is an acquired defense?

Answer 4

Specific defenses that we acquire throughout our lives

Question 5

List physical barriers to infection in a mammalian body.

Answer 5

This is just first line of defense (eg. skin, mucous membrane, lysozyme and hcl in stomach acid)

Question 6

List four chemical defenses.

Answer 6

• Lysozyme (in tears)
• Skin’s acidic pH
• Hydrochloric acid in stomach
• Digestive juices and bile of intestines (low pH 1.2-3.0)

Question 7

What are the three major tasks the immune system accomplishes for a healthy body?

Answer 7

• Protecting against harmful invaders
• Identifying and neutralizing harmful substances
• Recognizing and eliminating diseased or damaged cells

Question 8

What are monocytes and macrophages?

Answer 8

3-7% of WBCs, largest, kidney-shaped nucleus; phagocytic

Question 9

What are possible causes of a fever?

Answer 9

• Initiated by circulating pyrogens which reset the hypothalamus to increase body temperature

Question 10

Which white blood cells (leukocytes) are phagocytes?

Answer 10

Neutrophils and macrophages (think m&ms are phags bc they’re colours of the rainbow)

Question 11

What are dendritic cells? What are their functions?

Answer 11

Agranulocytes that trap pathogens and participate in immune reactions

Question 12

How do phagocytes kill bacteria?

Answer 12

They undergo phagocytosis where they engulf and digest the bacteria

Question 13

What are three basic functions of an inflammatory response?

think clean up crew

Answer 13

1. Eliminate initial cause of cell injury
2. Clear out necrotic cells and damaged tissues
3. Initiate tissue repair and restoration

Question 14

What is dolor, rubor, and calor?

Answer 14

Dolor- pain
Rubor- redness
Calor- warmth/heat

Question 14

The migration of cells out of blood vessels into the tissues is known as _________

Answer 14

Diapedesis

Question 14

What are leukocytes?

Answer 14

White blood cells: they recognize and differentiate any foreign material in the body

Question 15

What are lymphocytes?

(not to be confused with leukocytes)

Answer 15

20-35% of WBCs made up of B cells and T cells

Question 16

What are erythrocytes?

Answer 16

Red blood cells

Question 17

List different WBCs and their functions?

Answer 17

• Neutrophils: fight bacterial infection (neutrogena bacteria)
• Basophil: deal with allergic reaction and recruit other WBC to come to site of infection (basic allergies)
• Eosinophils: fight parasitic infections (ew parasites)
• Monocytes: phagocytic

Question 18

Composition of blood.

Answer 18

• Plasma (~55%): 92% water, metabolic proteins, clotting factors, hormones, etc
• Erythrocytes (~40%)
• Lymphocytes (~5%)

Question 19

What are hematopoietic stem cells?

Answer 19

Immature cells found in bone marrow and peripheral blood that can develop into different types of blood cells

Question 20

What is hemopoeisis?
a. Where does it take place in infants?
b. Where does it take place in adults?

Answer 20

It is the process of forming red and white blood cells and platelets
a. occurs in the yolk sac
b. occurs in the bone marrow

Question 21

What are humoral and cell-mediated immunities?

Answer 21

B (humoral): activated B cells produce antibodies

T (cell-mediated): activated T cells modulate immune functions and kill foreign cells

Question 22

________ are developed from bone marrow stem cells, lose nucleus and are simple biconcave sacs of hemoglobin while ________ are formed elements in circulating blood that are not whole cells

Answer 22

Erythrocytes, platelets

Question 23

List actions of second line of defense.

Answer 23

You PRIIC!!!! - Phagocytosis - Recognition - Inflammation - Interferon - Complement

Question 23

What is the function of the lymphatic system?

Answer 23

carries microbes to lymph nodes where lymphocytes and macrophages destroy the pathogen

Question 24

What are primary lymphoid organs?

Answer 24

Sites of lymphocytic origin and maturation- thymus and bone marrow

Question 25

Essay? What are signs and symptoms of inflammatory response?

Answer 25

- redness: increased circulation and vasodilation to injured tissues in response to chemical mediators (rubor) - warmth: heat given off by increased blood flow (calor) - swelling: increased fluid escaping into the tissue as blood vessels dilate, pus forms to prevent spread of infection - pain: stimulation of nerve endings (dolor)

Question 26

Which cells are most important in the development and maintenance of specific immunity to antigens?

Answer 26

B cells and T cells

Question 27

What two features are most characterized in immunity?

Answer 27

Specificity and memory

Question 28

Differentiate between active and passive immunization.

Answer 28

Active: results when a person is challenged with antigen that stimulates production of antibodies; creates memory, takes time, and is lasting Passive: performed antibodies are donated to an individual; does not create memory, acts immediately, and is short term

Question 29

Differentiate between natural and artificial immunity.

Answer 29

Natural: acquired as part of normal life experiences Artificial: acquired through a medical procedure such as a vaccine

Question 30

Define natural active, natural passive, artificial active and artificial passive immunization.

Answer 30

Natural: - Active: when person develops their own immune response to a microbe through infection - Passive: when person receives preformed immunity through the placenta or nursing Artificial: - Active: Vaccination - Passive: Antitoxin (given selected immune substances made by another individual like nursing a baby)

Question 31

What is clonal selection theory? Why is important?

Answer 31

The theory that each cell has a particular/ unique receptor specificity This is important because it makes it possible to understand how immunity works as well as