Immunology

Question 1

Two types of immune systems

Answer 1

1) Innate

2) Adaptive

Question 2

Antigen

Answer 2

foreign molecule that can initiate an immune response

Question 3

What does the innate immune system do?

Answer 3

1. Prevents entry to body through physical and chemical barriers
2. Detects entry of pathogens
3. Eliminates pathogens (inflammation)

Question 4

How does the immune system trigger an inflammatory response?

Answer 4

1. Macrophages release chemokines to recruit immune system cells to the site of the cut
2. Histamine dilate blood vessels, which makes them more permeable
3. Neutrophils are recruited to remove pathogens by phagocytosis

Question 5

Toll-like receptors

Answer 5

part of the innate immune system

bind to molecules that are found in pathogens that are not found in the self

Activates different! downstream pathways to combat infection

Question 6

General Characteristics of the innate immune system

Answer 6

1. Generic: can distinguish between bacteria vs. fungi, but not specific different strains of bacteria
2. Rapid
3. Ready at all times

Question 7

General characteristics of the adaptive immune system

Answer 7

1. Specific
2. Slow response
3. Must be activated

Question 8

Two types of lymphocytes

Answer 8

B-cells

T-cells

Question 9

B-cell vs. T-cell recognition

Answer 9

B-cell can bind directly to an epitope on an antigen

T-cells need the antigen to be presented to them

Question 10

Epitope

Answer 10

small region that a B-cell/T-cell can bind to on an antigen

Question 11

How are specific epitopes recognized?

Answer 11

there are variable regions in the antigen binding sites of B-cells and T-cells

Question 12

How are variable regions of antigen binding sites created by in B-cells and T-cells?

Answer 12

genetic recombination

Question 13

Clonal selection theory

Answer 13

lymphocytes carry unique receptors

only when there is a match to an antigen are they activated

it is only when the antigen is present and lymphocytes are activated that they undergo clonal expansion

Question 14

Why do you need booster shots?

Answer 14

Since according to clonal selection theory, lymphocytes only expand when the antigen is present, if the antigen is not presented for long periods of time, you will loose immunity

so you need booster shot to periodically reintroduce the antigen

Question 15

T-cell activation

Answer 15

1. Antigen is presented by dendritic cells and macrophages on MHC protein
2. Epitopes bind to grove of MHC protein
3. Depending on class of MHC protein, either cytotoxic T-cells or Helper T-cells will be activated

Question 16

How is T-cell activation an example of the innate and adaptive system working closely together?

Answer 16

antigen is presented to T-cell by dendritic cells and macrophages

these cells are part of the innate immune system

Question 17

Cytotoxic T-cells

Answer 17

Kill cells that are infected with an extracellular pathogen

Question 18

Helper T-cell

Answer 18

either activate cytotoxic T-cells or B-cells

Question 19

B-cell activation

Answer 19

1. B-cell binds directly to an epitope on an antigen
2. Antigen is internalized and presented on surface of B-cell by MHC proteins
3. MHC-protein complex interacts with a helper T-cell
4. Helper-T releases cytokines that activate the B-cell
5. Activated B-cell divides into plasma cells that produce large quantities of antibodies

Question 20

What is present in an activated B-cell?

Answer 20

a lot of rough ER to process antibodies to secrete

Question 21

Antibodies

Answer 21

produced by B-cells

mark pathogens for destruction

Question 22

Extracellular pathogens

Answer 22

eliminated through a combination of antibody production of plasma cells and activated phagocytosis

antibody production by plasma cells triggers a series of events in the humoral response

Question 23

Intracellular pathogens

Answer 23

infected cells in the body can advertise their infection by expressing a MHC protein on their surface

T-cells bind to MHC then secrete proteins that pass through the membrane and into the cytoplasm of the infected cell

T-cell detatches and Proteins trigger apoptosis