BMS 108 Ch. 15 Immune System

Question 0

What are stationary WBCs called and where are they located?

Answer 0

lymphatic cells; spleen and lymph nodes

Question 1

What are leukocytes and where are they located in the body?

Answer 1

White Blood Cells (WBCs); in blood, CT and lymph

Question 2

What are the four common pathogens?

Answer 2

1. Viruses
2. Bacteria
3. Parasites
4. Allergens

Question 3

What are viruses?

Answer 3

DNA or RNA with a protein coat

Question 4

What is bacteria?

Answer 4

Prokaryotic cells with a cell wall

Question 5

What are parasites?

Answer 5

An organism that lives on or in a host and gets its food from or at the expense of its host (mites, worms)

Question 6

What is an allergen?

Answer 6

A substance that is generally not pathogenic but triggers an immune response.

Question 7

How do we keep pathogens from getting (too deep) into our body?

Answer 7

1. Skin, stomach acid, cilia in respiratory tract, local antibacterial enzymes in mouth, vagina and semen.
2. Also have high number of immune cells in all mucous membrane that interface with the external world

Both are nonspecific/innate immune response.

Question 8

What happens once a pathogen gets in?

Answer 8

1 is nonspecific; #2 has both nonspecific and specific components.

1. Have local inflammation in attempt to prevent further/deeper invasion
2. Orchestrate a body wide immune response.

Question 9

What is an antigen?

Answer 9

• marker on the surface of a pathogen

- a protein or polysaccharide, or a mixture of both

Question 10

What is an antibody?

Answer 10

• Ag binding protein
• aka immunoglobin (5 classes: IgG, IgE, A, D, and M
• looks like a Y shape

Question 11

What is a complement system?

Answer 11

• Series of plasma proteins that can be assembled into a membrane/cell wall of a pathogen or infected cell
• Creates a hole in the cell and leads to lysis
• part of nonspecific immune response, but often turned on by specific immunity

Question 12

What are phagocytic cells?

Answer 12

-neutrophils and macrophages

Question 13

What are cytokines?

Answer 13

• collective term for all chemicals secreted by WBCs
• Spurs other immune cells to action by signaling the alarm
• Acts locally (autocrine & paracrine)

Question 14

Name are four specific cytokines?

Answer 14

1. Nitric Oxide
2. Interleukins
3. Tumor Necrotic Factor (TNF)
4. Interferon

Question 15

What is the function of Nitric Oxide?

Answer 15

toxic to microbes; vasodilator; used in long term potentiation

Question 16

What is the function of Interleukins?

Answer 16

promotes inflammation; increase proliferation and differentiation of T & B cells; indoginous pyrogens (inducing fever)

Question 17

What is the function of TNF?

Answer 17

stimulates release of histamine (vasodilator) from mast cells

Question 18

What is the function of Interferon?

Answer 18

interfere with replication of cells invaded by viruses

Question 19

What is inflammation?

Answer 19

Innate, nonspecific series of highly interrelated events in response to foreign invasion or tissue damage.

Question 20

What are the goals of inflammation?

Answer 20

to bring phagocytes and plasma proteins to a site of infection in order to:

1. Isolate, destroy or inactivate the invader
2. Remove debris
3. Prepare for subsequent healing

Question 21

List the steps in Inflammation.

Answer 21

1. Macrophages attack immediately
2. Mast cells release histamine&raquo_space; local vasodilation&raquo_space; increased capilary permeability&raquo_space; edema
3. Edema
4. Wall off inflamed area (isolate the pathogen with fibrin)
5. Increased number of neutrophils and macrophages
6. Opsonins mark bacteria for death
7. Phagocytes clear the area

Question 22

What are T lymphocytes?

Answer 22

• cell mediated immunity (hand to hand combat)

- usually focused on viruses and cancer cells

Question 23

What are B lymphocytes?

Answer 23

• humoral or Ab mediated immunity (fluids)

- usually focused on bacteria

Question 24

An individual B or T cell is highly ________ to ____ antigen.

Answer 24

specific; one

Question 25

How many receptors do T cells have on their surface? What is each for?

Answer 25

one for foreign Ag; one for self (MHCs)

Question 26

What are the three types of T cells?

Answer 26

1. Helper T cells
2. Cytotoxic T cells
3. Regulatory T cells

Question 27

What are the functions of Helper T cells?

Answer 27

1. Most numerous
2. Orchestrate most specific immune responses
3. Present Ag to Cyto T or B cells to activate them
4. Release cytokines (esp. ILs) that activate and proliferate T and B cells
5. Need other cells (macrophages and dendritic cells) to present the Ag to Helper T cells to get started.

Question 28

What is another name for Helper T cells?

Answer 28

CD4+

Question 29

What are the functions of Cytotoxic T cells?

Answer 29

1. Destroy a host cell bearing foreign Ag by HTH combat
2. Cyto T cell releases chemicals (eg perforins) which create holes in the infected cell plasma membrane
3. Also release granzymes which are similar to digestive enzymes

Question 30

What are the functions of B lymphocytes?

Answer 30

1. Antibodies
2. Activated by helper T cell presentation of Ag and cytokines
3. Differentiate into plasma cells and memory b cells

Question 31

What do plasma cells secrete?

Answer 31

antibodies

Question 32

How fast do plasma cells secrete Abs?

Answer 32

2000 per second

Question 33

Do Abs destroy cells?

Answer 33

No, mostly amplify innate immune responses.

Question 34

What are the 5 ways in which Abs help immune response?

Answer 34

1. Neutralize the antigen
2. Cause Agglutination
3. Activate Complement System
4. Enhances Phagocytosis
5. Signal NK cells

Question 35

What are the functions of Memory B cells?

Answer 35

1. Primed and ready for faster response during second exposure
2. Exploited for vaccination