Immune System

Question 1

immune system defenses

Answer 1

innate (non-specific) and adaptive (specific) defenses

Question 2

first innate defense

Answer 2

non-specific
surface barriers including:
skin and mucous membrane

Question 3

second innate defense

Answer 3

non-specific
internal defenses including:
phagocytes, natural killer cells, inflammation, antimicrobial proteins, and fever

Question 4

third adaptive defense

Answer 4

humoral (B cells) and cellular (T cells) immunity

Question 5

how intact skin epidermis defends

Answer 5

• a mechanical barrier
• acid mantle of skin
• keratin

Question 6

how mucous membrane defends

Answer 6

• a mechanical barrier

- mucus, nasal hairs, cilia, gastric juice (HCl), acid mantle of vagina, lacrimal secretion (tears)/saliva, urine

Question 7

lysozyme

Answer 7

an enzyme that destroys microorganisms found in lacrimal secretion (tears) and saliva

Question 8

how phagocytes defend

Answer 8

second line of defense

engulf and destroy pathogens

Question 9

how natural killer cells defend

Answer 9

second line of defense

apoptosis (cell suicide) and attacking virus infected cells

Question 10

how antimicrobial proteins defend

Answer 10

second line of defense

interferons and complement

Question 11

interferons

Answer 11

proteins released by virus infected cells and certain lymphocytes. They act as chemical messengers to protect uninfected tissue cells form viral takeover. mobilize immune system.

Question 12

complement

Answer 12

most effective
a group of 20 proteins in blood plasma and cell membrane, that when activated lyse microorganisms, enhance phagocytosis by opsonization, and intensify inflammatory/immune responses

Question 13

how fever defends

Answer 13

second line of defense

high body temps inhibits microbes from multiplying

Question 14

inflammatory chemicals

Answer 14

histamine, bradykinin, prostaglandins

Question 15

histamine

Answer 15

granules of mast cells and basophils

promote vasodilation of local arterioles and increase permeability (chemotaxis)

Question 16

interferon mechanism against viruses

Answer 16

1. virus enters the cell and takes over
2. interferon gene switches on
3. cell produces interferon molecules
4. interferon is released and connects to receptor and enters new cell binding to turn on genes for antiviral proteins
5. antiviral proteins are released and block viral reproduction

Question 17

complement activation

Answer 17

1. opsonization: coats pathogen surfaces
2. enhances inflammation: stimulates histamine release, increase blood vessel permeability, attracts phagocytes
3. insertion of MAC through holes in cell membrane causing cell lysis
4. phagocytosis cleans up remains

Question 18

MAC

Answer 18

membrane attack complex

creates hole in cell membrane that allows influx of water therefore lysing the cell

Question 19

local hyperemia

Answer 19

increased blood flow to an area
causes heat and redness
because inflammatory chemical caused arterioles to dilate

Question 20

when you have pain and swelling

Answer 20

its because inflammatory chemical were released that increased capillary permeability and the capillaries leak protein-rich fluid in tissue spaces

Question 21

events of phagocytosis

Answer 21

1. phagocyte adheres to pathogen or debris
2. endocytosis or ingestion creating a phagosome
3. lysosome fuses with phagosome forming a phagolysome
4. lysosomal enzymes digest the particles only leaving residual body
5. exocytosis removing residual material

Question 22

antigen + antibody

Answer 22

antigen and antibodies match up at antigen binding sites. There are different receptors for each antigen/antibody

Question 23

antibody structure

Answer 23

a Y shape: 1200 AA
have antigen binding sites
heavy chain: 400 AA
light chain: 200 AA

Question 24

immunoglobin

Answer 24

antibodies

Question 25

immunoglobin classes

Answer 25

IgD, IgM, IgG, IgA, IgE

Question 26

IgD immunoglobin

Answer 26

a monomer antigen receptor of the B cell important in B cell activation

Question 27

IgM immunoglobin

Answer 27

5-10% a monomer and pentamer first immunoglobin released by plasma potent agglutinating agent and readily activates and fixes complement

Question 28

IgG immunoglobin

Answer 28

most abundant (75-85%) and diverse antibody in plasma protects against bacteria and viruses fixes the complement crosses the placenta and confers passive immunity from mother to fetus

Question 29

IgA immunoglobin

Answer 29

10-15% the dimer is found in body secretions such as saliva and sweat and helps prevent attachment of pathogens to epithelial cell surfaces and mucosal barriers

Question 30

IgE immunoglobin

Answer 30

1% secreted by plasma cells in the skin, mucosae of theGI and respiratory tracts, and tonsils. causes the cells to release histamine and other chemicals that mediate inflammation and allergic reaction. levels in blood rise during severe allergic reactions.

Question 31

transferrins

Answer 31

antimicrobial substance an iron binding protein inhibits bacterial growth by reducing the amount of available iron

Question 32

C3

Answer 32

a plasma protein involved in complements

Question 33

immunity

Answer 33

is a resistance to a specific foreign agent such as pathogen by releasing or producing specific lymphocyte or antibody

Question 34

3 important aspects to immune response

Answer 34

1. antigen specific 2. systemic (not restricted to the initial infection site) 3. has memory (recognizes and performs stronger attacks on previously encountered pathogens)

Question 35

immune responses are carried out by..

Answer 35

lymphocytes (immunocytes) or white blood cells

Question 36

two types of lymphocytes

Answer 36

B and T cells/lymphocytes

Question 37

antibody-mediated (humoral) immunity

Answer 37

B cells transform into plasma cells which synthesize and secrete specific proteins called antibodies. Antibodies bind to particular antigens.

Question 38

cell mediated (cellular) immunity

Answer 38

T-lymphocytes migrate from the blood to the tissue, where they interact directly with antigens. They do not produce antibodies. The T-cells attack antigens.

Question 39

formation of T&B lymphocytes

Answer 39

lymphocytes develop from stem cell (hemocytoblast) in the red bone marrow

Question 40

t-cell/lymphocyte differentiation

Answer 40

after leaving the red bone marrow, lymphocyte reaches thymus gland and undergoes special processing to become differentiated.

Question 41

T-cell leaves thymus gland as

Answer 41

either 1. T-helper, T4, CD4+ 2. T-cytotoxic, Killer T-cells, T8, CD8+ * only respond to antigens with amino acids/protein*

Question 42

T-cells % of lymphocytes

Answer 42

70-80%

Question 43

b-cell/lymphocyte differentiation

Answer 43

they do not process into the thymus gland, but in another UNKNOWN part of the body. they differentiate into b-lymphocytes (B-cells)

Question 44

antigen

Answer 44

any substance capable of exciting our immune system and provoking an immune response

Question 45

what are antigens made of

Answer 45

large, complex molecules made of proteins, nucleic acids, polysaccharides, and some lipids

Question 46

haptens

Answer 46

smaller substances that have exciting ability but do not provoke immune responses. also called partial antigens. ex. penicillin reaction

Question 47

epitopes

Answer 47

antigenic determinants | specific portions of antigen molecules that do the triggering of immune response

Question 48

when B-cells respond

Answer 48

when antigen bearing agents are phagocytized and others are combined with B-cell receptors

Question 49

when helper T-cells respond during humoral immunity

Answer 49

interact with B-cell, release lymphokines, and stimulates B-cell to proliferate rapidly leading to clones

Question 50

primary humoral immune response

Answer 50

newly formed B-cell clones (plasma cells) secrete antibodies, form antigen-antibody complex, inactive antigen phagocytized

Question 51

secondary humoral immune response

Answer 51

other clone members have become memory B-cells, capable of mounting a rapid attack against the same antigen in future.

Question 52

antibody mechanisms

Answer 52

1. neutralization: masks dangerous parts of toxins or viruses 2. agglutination: clumping antigens into lattices 3. precipitation: trap antigens 4. complement: cell lysis(rupture)

Question 53

active humoral immunity

Answer 53

when B cells encounter antigens and produce antibodies against them

Question 54

passive humoral immunity

Answer 54

instead of making antibodies by plasma cells, your body is directly introduced to antibodies

Question 55

naturally acquired active humoral immunity

Answer 55

infection, contact with pathogen (all diseases)

Question 56

artificially acquired active humoral immunity

Answer 56

vaccine, contact with dead or weak pathogen

Question 57

naturally acquired passive humoral immunity

Answer 57

antibodies passed from mother to fetus

Question 58

artificially acquired passive humoral immunity

Answer 58

direct injection of antibodies (anti-venom)

Question 59

cytotoxic T-cells killing mechanism

Answer 59

1. Tc identifies foreign antigens and binds tightly to target cell 2. Tc releases perforin and granzyme molecules 3. Perforin creates a hole in target cell membrane and granzyme enters into the target cell. granzyme triggers apoptosis. 4. Tc detaches and searches for new prey

Question 60

helper t-cells in cellular immunity

Answer 60

1. Th cell binds to dendritic cell 2. Th cell stimulates dendritic cell to express co-stimulatory molecules 3. dendritic cell can now activate CD8 cell and becomes Tc/CD8 cell