Lecture 13b Immune System

Question 1

Name the 4 classes of pathogens

Answer 1

• Viruses
• Bacteria
• Fungi
• Parasites

Question 2

What is the difference between Innate and Adaptive Immunity?

Answer 2

Innate is evolutionarily ancient, fully formed when young, rapid, and fights off random invaders

Adaptive is evolutionarily new, learns from each infection, slow, and defeats specific pathogens

Question 3

What lines of defense are considered Innate? Adaptive?

Answer 3

First and second considered innate

Third considered adaptive

Question 4

Skin, mucous membranes, and their secretions are which line of defense?

Answer 4

First

Question 5

Lymphocytes, antibodies, macrophages and dendritic cells are considered which of line of defense?

Answer 5

Third

Question 6

Phagocytic cells (M,N,E and dendritic cells), antimicrobial proteins and the inflammatory response are considered what line of defense?

Answer 6

Second

Question 7

What are macrophages considered as?

Answer 7

APCs: antigen presenting cells

Question 8

Do neutrophils present antigens?

Answer 8

NO

Question 9

Besides macrophages, what other phagocyte is considered an APC (antigen presenting cell)?

Answer 9

Dendritic cells

Question 10

How do phagocytes know what to ingest?

Answer 10

They use an innate system of receptors

Question 11

How do phagocytic cells distinguish self from nonself?

Answer 11

They recognise PAMPs (pathogen associated molecular pattens) because they have pathogen recognition receptors (PRPs) such as toll-like receptors

Question 12

Is inflammation specific or nonspecific?
What is inflammation?

Answer 12

-Nonspecific
- A composite of multiple actions (basically throws several punches at invader hoping one of them lands hard)

Question 13

What does histamine stimulated vasodilation cause for inflammation?

Answer 13

Redness and warmth

Question 14

What in innate immunity is regulated by the hypothalamus?

What chemical signals the hypothalamus to set body temp higher?

Answer 14

Fever

Endogenous pyrogen

Question 15

Where do B and T cells originate and where are they “educated”?

Answer 15

Originates in the red bone marrow

T educated in Thymus
B educated in Bone marrow

Question 16

Educated/ mature T and B cells can later respond to antigens. What is this called?

Answer 16

Activation

Question 17

True or False: Most T and B cells will never activate

Answer 17

True: they remain naive forever

Question 18

What do activated lymphocytes differentiate into?

Answer 18

Effector and memory lymphocytes

Question 19

Which cells directly kill foreign cells after activation?

Answer 19

CD8+ Cytotoxic T cells

Question 20

Which cells make antibodies that help destroy antigens?

Answer 20

Plasma (B) cells

Question 21

Which Cells present possible antigens to T and B lymphocytes?

Answer 21

Dendritic cells and macrophages

Question 21

Which cell tells b cells to differentiate into plasma cells, enhance activity of cytotoxic t cells and tell macrophages to work faster?

Answer 21

CD4+ Helper T cells

Question 21

What are the two Major Histocompatibility Complex systems that antigen presentations use?

Answer 21

MHC-I and MHC-II

Question 21

True or False: A T or B cell receptor is specific to multiple epitopes for the cells’ entire lifetime

Answer 21

False: They are only specific to a single epitope

Question 21

When does T cell activation begin?

Answer 21

When cells show correct antigen/ epitope to matching naive T cells

Question 22

What is MHC-I used for?

Answer 22

displays antigens to CD8+ cytotoxic T cells. "I found this thing, does it match what you're looking for?"

Question 23

What is MHC-II used for?

Answer 23

displays phagocytosed proteins to CD4+ helper T cells. "I ate this thing, does it match what you're looking for?"

Question 24

How do Cytotoxic T cells attack foreign eukaryotic cells?

Answer 24

They bind to antigen-bearing cells and secrete proteins that lyse the foreign cell's membrane and trigger apoptosis.

Question 25

What activation does Memory cells wait for? Describe it

Answer 25

Secondary activation differentiate and divide memory cells faster, more numerous, make 10 to 1000 times more antibody than original plasma cells

Question 26

What is the structure of an antibody?

Answer 26

Two long heavy chains joined to two shorter light chains (looks like Y) Bottom is constant across different antibodies whereas top varies and allows for antigen specificity

Question 27

Where is the antigen binding site located?

Answer 27

The tips of the short chains

Question 28

What are the different types of antibody actions?

Answer 28

- Viral inhibition - Neutralization - Opsonization - Agglutination - Precipitation - Phagocytosis

Question 29

Which AA reacts with molecules at the viral surface and prevent viral attachment to cells?

Answer 29

Viral inhibition

Question 30

Which AA combines with antigens on the cell surface and binds cells together/ restrict their movement?

Answer 30

Agglutination

Question 31

Which AA combines with dissolved antigens to form lattice-like arrangements that precipitate out of solution?

Answer 31

Precipitation

Question 32

Which AA prevents bacterial attachment to cells?

Answer 32

Opsonization

Question 33

Which AA combine specifically with toxins or microbes, thereby neutralizing them and preventing attachment to cells?

Answer 33

Neutralization

Question 34

Which AA is enhanced by the other AAs?

Answer 34

Phagocytosis