lymphoid system 2

Question 1

antigens are

Answer 1

any molecule that is recognized by cells of the adaptive immunity
- usually surface proteins of a pathogen

Question 2

antibodies are:

Answer 2

glycoproteins in the immunoglobulin family that interact directly with antigens
- B lymphocytes>Plasma>antibodies

Question 3

classes of antibodies
(Ig=immunoglobulin)

Answer 3

• IgE
• IgG
• IgA

Question 4

IgE

Answer 4

• primarily in plasma
• in presence of allergies

Question 5

IgG

Answer 5

• most common
• in the plasma
• neutralize antigens

Question 6

IgA

Answer 6

• primary secretory immunoglobulin
• in saliva and milk

Question 7

innate immunity

Answer 7

• immediate
• non specific
• physical barriers
• targets wide variety of pathogens
• neutrophils
• toll-like receptors (TLRs)
• natural killer cells (NKC)
• antimicrobial chemicals produced by leukocytes

Question 8

antigen presenting cells include:

Answer 8

• macrophages
• dendritic cells in lymphoid organs
• thymic epithelial cells

Question 9

stimulated phagocytosis

Answer 9

directed cell killing by innate immune cells

Question 10

marginating compartment

Answer 10

compartments where diapedesis occurs as well as different locations on endothelial lining (step 3)

Question 11

adaptive immunity

Answer 11

• specific
• mediated by lymphocytes and antigen-presenting cells
• has ability to remember specific pathogens (memory)

Question 12

a molecule recognized by cells are called

Answer 12

antigens

Question 13

antigens consist of

Answer 13

soluble molecules (proteins and polysaccharides)

Question 14

immune cells recognize and react to

Answer 14

small molecular domains of the antigen known as antigenic determinants or epitopes (site of binding)

Question 15

immune response can be

Answer 15

• cellular
• humoral
• both

Question 16

cellular immune response is controlled by

Answer 16

lymphocytes

Question 17

humoral immune response is controlled by

Answer 17

antibodies

Question 18

characteristics of immunoglobulins

Answer 18

• heterotetomers bonded by disulfide bonds
• end terminal region is variable
• Fc region

Question 19

heterotetomers of antibodies include

Answer 19

2 light chains and 2 heavy chains

Question 20

IgG and IgA have the ability to

Answer 20

• bind specifically and neutralize viral/bacterial toxins
• agglutinate bacterial cells
• precipitates soluble antigens

Question 21

NK cells activation

Answer 21

• antibodies bound to antigen on virus infected cells
• recognized by primitive lymphocytes
• activated to kill infected cell by releasing perforin and granzymes

Question 22

Major Histological complex has

Answer 22

2 classes

Question 23

MHC class I

Answer 23

• self antigen
• T cells recognize this and do not bind to the cells this marker is on
• presents on surface of nucleated cells
• is not presented on RBCs and platelets

Question 24

MHC class II

Answer 24

• foreign antigen
• T lymphocytes recognize this marker, bind, and eliminate the marked cell

Question 25

markers of T lymphocytes

Answer 25

CD4 and CD8

Question 26

CD4 marked T cells

Answer 26

- are helper T cells - bind to MHC class II presenting cells - produce cytokines to differentiate B cells into plasma cells - can become long lived memory T cells - can help activate cytotoxic T cells

Question 27

CD8 marked T cells

Answer 27

- are cytotoxic T cells - trigger apoptosis in MHC class I (self) presenting cells that are infected - activated by helper T cells (CD4) to help eliminate MHC II (toxic) presenting cells

Question 28

T cell maturation

Answer 28

- occurs in thymus - positive selection - negative selection

Question 29

positive selection

Answer 29

- first step in maturation - occurs in cortex - checks to see if T cells bind to MHC molecule presented - if yes = survive and move to medulla (weak binding is good enough) - if no = death - because if they cannot bind to MHC they cannot carry out their function

Question 30

negative selection

Answer 30

- second step in maturation - happens in medulla of thymus - checks to see if T cells bind to MHC I - if yes = cell dies - if no = cell survived maturation and can leave thymus

Question 31

what is diapedesis?

Answer 31

the passage of blood cells through the walls of the capillaries, typically accompanying inflammation