CH 16-17 immune Responses

Question 1

Immune System

Answer 1

Immune System- Large, complex, and diffuse network of cells and fluids that penetrate into every organ and tissue.

It provides a multi layer defense against potential pathogens

Question 2

What are the four major subdivisions of the immune system?

Answer 2

Four major subdivisions of immune system:

1. Reticuloendothelial system (RES)
2. Extracellular fluid (ECF)
3. Bloodstream
4. Lymphatic system

Question 3

Reticuloendothelial System (RES)

Answer 3

Reticuloendothelial System (RES) 
Network of connective tissue fibers that interconnects other cells and meshes with the connective tissue network surrounding organs 

Inhabited by phagocytic cells

Question 4

Plasma

Answer 4

Plasma – 92% water, metabolic proteins, globulins, clotting factors, hormones, and all other chemicals and gases to support normal physiological functions

Question 5

Erythrocytes

Answer 5

Red blood cells

Question 6

Leukocytes

Answer 6

Leukocytes – White blood cells

– Granulocytes: lobed nucleus

– Agranulocytes: unlobed, rounded nucleus

Question 7

Granulocytes

Agranulocytes

Answer 7

Both are types of white blood cells
– Granulocytes: lobed nucleus
– Agranulocytes: unlobed, rounded nucleus

Question 8

Platelets

Answer 8

– clotting, inflammation

Question 9

Hemopoiesis

Answer 9

Hemopoiesis – production of blood cells

Question 10

Diapedesis

Answer 10

Diapedesis – migration of cells out of blood vessels into the tissues

Question 11

Chemotaxis

Answer 11

Chemotaxis – migration in response to specific chemicals at the site of injury or infection

Question 12

What does the Lymphatic System do?

Answer 12

1. Provides an auxiliary route for return of extracellular fluid to the circulatory system
2. Acts as a drain-off system for the inflammatory response
3. Renders surveillance, recognition, and protection against foreign material

Question 13

What is Lymph?

Answer 13

Lymphatic Fluid or Lymph is a plasma-like liquid carried by lymphatic circulation

Formed when blood components move out of blood vessels into extracellular spaces

Made up of water, dissolved salts, 2-5% proteins

Transports white blood cells, fats, cellular debris, and infectious agents

Question 14

What are the Lymphoid organs?

Answer 14

Thymus – high rate of growth and activity until puberty, then begins to shrink; site of T-cell maturation

Lymph nodes – small, encapsulated, bean-shaped organs stationed along lymphatic channels and large blood vessels of the thoracic and abdominal cavities

Spleen – structurally similar to lymph node; filters circulating blood to remove worn out RBCs and pathogens

Question 15

What is the cellular fingerprint?

Answer 15

Recognition proteins are capable of identifying which cells are your own (self) and which are viruses/foreign (not self)

Question 16

What do white blood cells (Leukocytes) recognize as foreign material?

Answer 16

Viruses/antigens

Question 17

Antigens

Answer 17

large complex molecules over 10,000 MW are most antigenic

Molecules that stimulate an immune response.

The basis for most immune responses is the encounter between antigens and white blood cells

Lymph nodes and spleen concentrate the antigens and circulate them so they will come into contact with lymphocytes

Question 18

epitope

Answer 18

is the part of an antigen that is recognized by the immune system

the epitope is the specific piece of the antigen to which an antibody binds.

Question 19

What are the three layers of defense against antigens?

First one

Answer 19

1. Barriers to prevent entry
   - Skin,
   - Mucosal layers
   - Flushing with fluids

Question 20

What are the three layers of defense against antigens?

Second one

Answer 20

2. Innate or nonspecific response- fast, general response
   - Phagocytosis
   - Inflammation
   - Interferon
   - complementary system

Question 21

What are the three layers of defense against antigens?

Third one

Answer 21

3. Third line of defense – Acquired or specific response is slower to develop
   - strong targeted response
   - Macrophages and Lymphocytes
   - memory cells

Question 22

Skin

Answer 22

Composed of epithelial cells Compacted Cemented together Impregnated with keratin

Very few pathogens can penetrate if intact

First layer of defense

Question 23

Production & flushing of fluids:

Mucosal Membranes

Answer 23

flushing of fluids: 
 Tears 
 Saliva 
 Stomach acid 
 Sweat 

Mucosal Membranes
 Deter attachment of microbes

Question 24

Inflammatory Response

Answer 24

Second Layer
Generalized, non-specific response Triggered by tissue damage Redness, swelling, pain, fever
Increases blood flow pulling more white-blood cells to infected/inflamed area

Question 25

Fever

Answer 25

Initiated by pyrogens (exogenous, endogenous) Benefits: – Inhibits multiplication of temperature-sensitive microorganisms – Impedes nutrition of bacteria by reducing the available iron – Increases metabolism and stimulates immune reactions and protective physiological processes

Question 26

Phagocytosis

Answer 26

Second layer

1. To survey tissue compartments and discover microbes, particulate matter, and dead or injured cells
2. To ingest and eliminate these materials
3. To extract immunogenic information from foreign matter

Question 27

Neutrophils

Answer 27

Neutrophils – general-purpose; react early to bacteria and other foreign materials, and to damaged tissue

Question 28

Eosinophils

Answer 28

Eosinophils – attracted to sites of parasitic infections and antigen-antibody reactions

Question 29

Macrophages

Answer 29

Macrophages – derived from monocytes; scavenge and process foreign substances to prepare them for reactions with B and T lymphocytes

Question 30

Interferon

Answer 30

Small protein produced by certain WBCs and tissue cells
 Produced in response mostly to viruses
 Bind to cell surfaces and induce expression of antiviral proteins
 Inhibit expression of cancer genes

Question 31

Acquired or Specific Immunity

Answer 31

Third layer of defense

Acquired immunity to specific pathogens Slowest to develop, but strongest reaction

Also called adaptive immunity

Question 32

– Specificity

Answer 32

– Specificity – antibodies produced, function only against the antigen that they were produced in response to

Question 33

– Diversit

Answer 33

– Diversity – must be able to recognize any potential pathogen, even those that didn’t exist at birth

Question 34

– Memory

Answer 34

– Memory – lymphocytes are programmed to “recall” their first encounter with an antigen and respond rapidly to subsequent encounters

Question 35

Literally an endless number of different antigens that our bodies may be exposed to:
 Cells – bacteria, fungi, protists, helminthes
 Viruses
 Pollen, contaminants
 Large chemicals Immune system must contain a ______ with a matching antigen receptor for each of the _____ of potential antigens to be effective

Answer 35

Lymphocyte

Billions

Question 36

How does our body generate such a huge diversity of different lymphocytes?

Answer 36

Theory that describes the generation of the immune systems diversity

We have over 500 different genes that produce a diverse array of antigen receptors These genes are randomly ‘sliced & diced’ into different combinations in each lymphocyte

Question 37

Clonal Selection Theory

Number of genes + random mixing results in potential to make ____ to ____different lymphocytes each with unique antigen receptors in each person

Answer 37

10^14 to 10^18

Question 38

What about lymphocytes that contain antigen receptors for ‘self’ antigens?

Answer 38

Self-recognizing antigen receptors
Chance alone ensures millions of self recognizing lymphocytes These cells are ‘silenced’ or killed before they spread throughout the body

Question 39

Activation of the Specific response includes:

Answer 39

Macrophage phagocytosis and presentation of antigens
 Helper T-cells that have ARCs to match the antigens undergo
clonal selection to activate:
o B-Cells to produce antibodies and memory cells
o T-Cells to produce cytotoxic T-cells and memory cells