Chapter 21.4 - 21.6 - adaptive immune system

Question 1

What are antigens?

Answer 1

Substances that can mobilize adaptive defenses and provoke an immune response

Question 2

What are two important functional properties complete antigens?

Answer 2

Immunogenicity: ability to stimulate proliferation of specific lymphocytes
reactivity: ability to react with activated lymphocytes and antibodies released by immunogenic reactions

Question 3

What are incomplete antigens?

Answer 3

also called haptens, involve molecules too small to be seen so are not immunogenic by themselves

Question 4

When becomes a hapten immunogenic?

Answer 4

If hapten attaches to body’s own proteins

Question 5

What are antigenic determinants?

Answer 5

Certain parts of an entire antigen that are immunogenic

Question 6

What binds to atigenic determinants?

Answer 6

Antibodies and lymphocytes

Question 7

What are self-antigens?

Answer 7

All cells are covered with variety of proteins located on surface that are not atigentic to seld, but may be antigenic to others in transfusions or grafts

Question 8

What is an important group of self-proteins?

Answer 8

MHC proteins

Question 9

What does a MHC protein contain?

Answer 9

A groove that can hold piece of self-antigen or foreign antigen

Question 10

When can T lymphocytes recognize antigens?

Answer 10

When they are presented on MHC proteins

Question 11

Where are class I MHC proteins found?

Answer 11

All body cells

Question 12

Where are class II MHC proteins found?

Answer 12

Cells in the immune response

Question 13

Which helps mobilize adaptive defenses?

Answer 13

In infected cells MHC proteins display fragments of foreign antigens

Question 14

What are three crucial types of cells in the adaptive immune system?

Answer 14

B and T lymphocytes and Antigen-presenting cells

Question 15

Where do B cells mature?

Answer 15

The red bone marrow

Question 16

Where do T cells mature

Answer 16

In the thymus

Question 17

What is immunocompetence?

Answer 17

They are able to recognize and bind to a specific atigen

Question 18

To where are naive B and T cells exported

Answer 18

Lymph nodes, spleen and other lymphoid organs

Question 19

What are major types of APCs?

Answer 19

Dendritic cells, macrophages and B cells

Question 20

How do dendritic cells work?

Answer 20

Phagocytize pathogens that enter tissues, then enter lymphatics to present antigens to t cells in lymph node

Question 21

How do macrophages work?

Answer 21

Present antigens to T cells which not only activates T cell, but also further activates macrophages

Question 22

How do B lymphocytes work?

Answer 22

Present antigens to helper T cell to assist their own activation

Question 23

When is the humoral immune response provoked?

Answer 23

When B cell encounters target antigen, antibodies specific for that particular antigen are then produced

Question 24

When are B cells activated?

Answer 24

When antigens bind to surface receptors, cross-linking them

Question 25

What is the function of memory cells

Answer 25

Provide immunological memory
Mount an immediate response to future exposures to same antigen