lect 24: immune and lympathetic system I

Question 1

what are characteristics of innate immunity

Answer 1

lack immune specificity and memory
response=inflammation
neutrophils are the first responders

Question 2

what are the characteristics of acquired immunity

Answer 2

develops in response to antigens
more powerful than innate immunity
takes longer to develop
displays specificity and memory

Question 3

what is passive immunity

Answer 3

temporary immunity due to donated antibodies

Question 4

what is active immunity

Answer 4

long-lasting/permanent immunity due to self-exposure to antigen resulting in memory T cells and B cells specific for antigen

Question 5

what are the 2 types of acquired/adaptive immunity

Answer 5

humoral: antibody mediated; plasma cells

cell-mediated: T cells, B cells & antigen presenting cells

Question 6

define primary lymphoid organs

Answer 6

precursor cells mature into immunocompetent cells. Each is programmed to recognize a specific antigen (Thymus and bone marrow)

Question 7

define secondary lymphoid organs

Answer 7

trapped antigens stimulate clonal expansions of mature T and B cells (lymph nodes, spleen, tonsils)

Question 8

where do lymphocytes originate

Answer 8

primary lymphoid organs

Question 9

where do lymphocytes take up residence

Answer 9

secondary lymphoid organs

Question 10

what are attributes of lymph follicles (nodules)

Answer 10

not enclosed within a capsule
occur singly or in aggregates
are sites of B cell localization and proliferation
transient

Question 11

what are attributes of primary follicles

Answer 11

spherical, tightly packed accumulations of virgin B cells and dendritic reticular cells that have not been exposed to antigens

Question 12

what are attributes of secondary follicles

Answer 12

derived from primary follicles that have been exposed to non-self antigens.
Not present at birth

Question 13

what are attributes of the corona (cortex) of secondary lymph follicles

Answer 13

darker peripheral region

composed of densely packed B lymphocytes

Question 14

central, lighter stained region
composed of B lymphocytes, memory B cells, plasma cells, dendritic reticular cells which function as antigen-presenting cells

Answer 14

Germinal center of secondary lymph follicle

Question 15

T/F: lymph capillaries are present in lymphoid follicles

Answer 15

FALSE: they are not present

Question 16

where is subcutaneous-associated lymphoid tissue found

Answer 16

papillary layer of the dermis

Question 17

what does the lamina propria-associated lymphoid tissue include

Answer 17

MALT, BALT, GALT

Question 18

what does aggregated lymphoid tissue include

Answer 18

various tonsils and Peyer’s patches in the ilium

Question 19

where do all immune system cells originate

Answer 19

bone marrow

Question 20

where do immature T cells travel to?

Answer 20

thymus

Question 21

where do B cells travel to

Answer 21

specific regions in lymphoid tissues

Question 22

what cell surface receptors are needed for the maturation of B cells

Answer 22

IgM and IgD
MHC class II proteins
Complement receptors
Ig Fc receptors

Question 23

what are the 5 classes of antibodies

Answer 23

IgA, IgD, IgG, IgM, IgE

Question 24

what does the highly variable region of antibodies recognize

Answer 24

antigen and Fab fragment

Question 25

what are components of the less variable regions of the antibody structure

Answer 25

Fc fragment and binds antibody to cells

Question 26

where is IgA found

Answer 26

saliva, GU and respiratory tracts

Question 27

where is IgD found

Answer 27

found on surface of B cells traveling to lymphoid organs

Question 28

what is IgG

Answer 28

major Ig in blood | responsible for most antibody activity

Question 29

what is IgE

Answer 29

associated with allergic responses

Question 30

what is IgM

Answer 30

first antibody class expressed by developing B cells

Question 31

what is the main function of MHC gene products

Answer 31

presentation of antigenic peptides to T cells

Question 32

where is MHC 1 expressed

Answer 32

surface of all cells except trophoblast and RBC

Question 33

where is MHC 2 expressed

Answer 33

surface of B cells and antigen-presenting cells

Question 34

what do CD8+ T cells do

Answer 34

recognize peptide fragments of foreign peptides bound to MHC class I on the surface of cells (antigen present cell) cytolytic T cells undergo mitosis mediators of cell immunity

Question 35

what is required for the binding of MHC 1 protein fragments

Answer 35

both CD8 and T cell antigen receptor

Question 36

what does CD4+ do

Answer 36

recognizes peptide fragments of foreign proteins bound to MHC class II proteins on surface of APCs Helper T cells assist CD8+ cell differentiation assist B cell differentiation

Question 37

what releases Fas ligand

Answer 37

CD8+ T cells

Question 38

what is another name for CD16+ T cells

Answer 38

natural killer cells

Question 39

what does interleukin-2 do

Answer 39

stimulates proliferation of NK cells

Question 40

what does interferon gamma do

Answer 40

activates NK cells

Question 41

what does Tumor necrosis factor do (TNF-beta)

Answer 41

kills tumor cells directly

Question 42

what region of the class I MHC does CD8 bind to

Answer 42

alpha 3 region

Question 43

what does coreceptor CD4 bind to

Answer 43

beta 2 region of class II MHC

Question 44

what happens to activated T cells that undergo mitosis

Answer 44

either become memory cells or secrete interleukins

Question 45

what do B cells that undergo mitosis become

Answer 45

either plasma cells (which secrete appropriate antibodies) or memory cells

Question 46

what do cytokines do

Answer 46

activate macrophages to become more effective in killing target cells

Question 47

what is the classic pathway of the complement system activated by

Answer 47

antibody binding to a pathogen

Question 48

what is the alternate pathway of complement system activated by

Answer 48

directly activated by the pathogen

Question 49

what does the complement system facilitate

Answer 49

inflammatory responses

Question 50

what initiates the complement cascade

Answer 50

C1q binds to Fc region of Ig--> activates C1r--> activates C1s--> initiates complement cascade

Question 51

what is the most important opsonin

Answer 51

C3b

Question 52

what forms the pores in the membrane of the pathogen in the complement system

Answer 52

C6, C7, and C8

Question 53

what activates the MAC

Answer 53

complement cascade

Question 54

define opsonins

Answer 54

coatings that make the antigens more palatable to phagocytes

Question 55

consists of cells that typically pack areas of the lymphoid organ (mostly lymphocytes)

Answer 55

parenchyma

Question 56

consists mostly of reticular fibers and cells, including undifferentiated cells and fixed and free macrophages

Answer 56

stroma

Question 57

define Hilus

Answer 57

entry and exit point for vessels

Question 58

what enters through the hilus

Answer 58

efferent lymphatic vessels as well as arteries and veins

Question 59

where do afferent lymphatic vessels enter in lymph nodes

Answer 59

convex side of the node

Question 60

what fibers are in the capsule

Answer 60

dense collagen fibers, some elastic fibers, and smooth muscle fibers

Question 61

what are attributes of the deep (inner) cortex)

Answer 61

contains T helper cells, macrophages | HEVs

Question 62

define High endothelial venues (HEVs)

Answer 62

port of entry for circulating differentiated lymphocytes to seed lymph node

Question 63

irregular arrangement of loos medullary sinuses and dense medullary cords site of lymphocyte reentry into lymph stream thymic-dependent areas in subcortical and deeper medullary regions

Answer 63

medulla