Immune system Ch 21

Question 1

2 types of immunity

Answer 1

Innate

Adaptive

Question 2

Innate immunity/non-specific

Answer 2

First line defense, skin and body membranes.
Second line: hallmark is inflammation and consists of antimicrobial proteins, phagocytes and other cells that inhibit invaders.
Involves lectins

Question 3

Adaptive Immunity/specific

Answer 3

Third line of defense, consists of humoral and cellular immunity
Involves antibodies
Attack specific invaders and is slower to respomd

Question 4

Protective materials in skin and mucous membranes

Answer 4

Acid mantel of the skin
Enzymes: found in saliva, respiratory mucus and eye.
Mucin: lines the digestive and respiratory tracts
Defensins: broad spectrum antimicrobial peptides secreted by the skin and mucus membranes
Other chemicals: in the skin sebum and eccrine sweat are toxic to bacteria.

Question 5

Phagocytes

Answer 5

Neurophils: most abundant
Macrophages: most voracious and derive from monocytes

Question 6

Opsonization

Answer 6

Any pathogen that is coated with complement proteins called opsonins. These are markers to identify them as an invader.

Question 7

Natural Killer cells

Answer 7

Police the blood and immune system to find and lyse cancer and virus infected cells before the adaptive immune system is activated.

Question 8

Inflammation response

Answer 8

Triggered when ever there is tissue damage
Prevents the spread of damaging agents to surrounding tissue
Disposes of cell debris and pathogens
Alerts adaptive immune system
Sets the stage for repair
Mast cells are a key component and release histamine

Question 9

Phagocyte mobilization

Answer 9

Leukocytosis: Neurophils enter the blood from bone marrow
Margination: Neurophils cling to capillary wall
Diapedesis: They then flatten and squees out of the capillary
Chemotaxis: neutophils follow chemical trail.

Question 10

Chemotaxis

Answer 10

Inflammatory chemicals act as homing devices and WBC migrate to the site of inflammation

Question 11

Interferons

Answer 11

Small proteins that help protect cells that have not yet been infected. IFN’s diffuse to nearby cells from infected cells and interfer with viral replication of DNA and blocking protein synthesis

Question 12

Complament System

Answer 12

The major mechanism of destroying foreign substances in the body. A group of 20 plasma proteins that normally circulate in the blood. When activated they lyse and kill invaders
Complements both active and innate immune systems

Question 13

3 important factors of adaptive response

Answer 13

It is specific
It is systemic
it has memory

Question 14

Humoral immunity

Answer 14

Antibody mediated immunity, provided by antibodies present in the bodies fluids.

Question 15

Cellular Immunity

Answer 15

Cell-mediated immunity: when lymphocytes themselves rather than antibodies, defend the body.
Directly: by killing infected cells
Indirectly: by releasing chemicals that enhance the inflammatory response and activate other WBCs

Question 16

Antigens

Answer 16

Substances that can mobilize active defenses and provoke immune responses. Not normally in the body and recognized as not self

Question 17

Complete antigens

Answer 17

Immunogenicity: the ability to stimulate specific lymphocytes to multiply
Reactivity: the ability to react with activated lymphocytes and antibodies

Question 18

Incomplete antigens

Answer 18

Unless attached to a protein carriers hapens have reactivity but not immunogenicity.

Question 19

MHC Proteins

Answer 19

A group of glucoproteins that are on the cell surface and identify it as self.

Question 20

B Cells

Answer 20

Oversee humoral immunity, Activate helper T cell (not naive)

Question 21

T Cells

Answer 21

Non-antibody producing, cellular arm of adaptive immunity

Question 22

T Cell education is composed of

Answer 22

Positive and negative selection in the thymus

Question 23

Positive selection

Answer 23

The first test the T cells must pass. It ensures that only the T cells that can recognize self-MHC proteins survives

Question 24

Negative selection

Answer 24

The second test makes sure that T cells do not recognize self-antigens displayed on self-HMC.

Question 25

Antigen presenting cells

Answer 25

APC Engulf antigens and present pieces of them on their surfaces like flags for the T cells to recognize.

Question 26

Dendritic Cells

Answer 26

Found in the bodies frontiers (skin) where they act as sentinels with wispy extensions, very efficient antigen catchers/presenters. One of the key links between innate and adaptive immunity.

Question 27

Memory Cells

Answer 27

Clone cells that do not become plasma cells. They can mount an almost immediate humoral response if they encounter the same antigen again in the future.

Question 28

Primary immune response

Answer 28

Occurs on the first exposure to an antigen. Lag time of 3-6 days.

Question 29

Secondary immune response

Answer 29

When someone is reexposure to the same antigen, faster more prolonged and more effective than primary responses. Provide immunological memory

Question 30

Active humoral immunity

Answer 30

When B cells encounter antigens and produce antibodies against them

Question 31

Passive humoral immunity

Answer 31

Instead of being made in your plasma, ready made antibodies are introduced into your body. In this case B cells are not challenged by antigens and immunological memory does not occur and protection is borrowed and temporary.

Question 32

Antibodies

Answer 32

Also called immunoglobulins. Proteins secreted in response to an antigen by B cells called plasma cells and antibodies bind specifically with that antigen.

Question 33

Antibody classes

Answer 33

MADGE IgM:readily fixes and activated complament IgA: Found in body secretions IgD: Found on B Cell surface, antigen receptor IgG: Most abundant in plasma, fixes and activates complament IgE: binds to mast cells and basophils and stimulates inflmmation and allergic reaction

Question 34

Antigen-Antibody complexes

Answer 34

Neutralization Agglutination Precipitation Complement

Question 35

Neutralization

Answer 35

Masks dangerous parts of bacterial exotoxins: viruses. As a result they cannot bind to receptors on tissue cells. Then phagocytes come in

Question 36

Agglutination

Answer 36

Cross linked antigen complexes form lattices and cause the cells to clump together

Question 37

Precipitation

Answer 37

Cross linked molecules are into large complexes. Soluble antigens.

Question 38

Complement fixation and activation

Answer 38

The chief antibody used against cellular antigens. Multiple antibodies bind to invaders cell membrane which allows materials in to lyse the cell

Question 39

Cellular immunity

Answer 39

CD4: Usually become helper T cells that help activate B cells and other T cells and macrophages Some become regulatory T cells which moderate immune response. CD8: Become cytoxic T cells,that destroy any cells in the body that harbor anything foreign.