2 - Organs, Tissues, and Immune Cell Trafficking

Question 1

differentiation pathway of immune cells are determined by what

Answer 1

growth factors and interactions w/ supporting cells

Question 2

what does pluripotent mean

Answer 2

it can differentiate into different lineages

Question 3

pluripotent stem cells differentiate into what

Answer 3

myeloid and lymphoid progenitor

Question 4

lymphoid progenitor diferentiates into what

Answer 4

B lymphocyte, T lymphocyte, and NC cells

Question 5

myeloid progenitor diff into what

Answer 5

granulocyte monocyte CFU, bacophil CFI, and. eosinophil CFU

Question 6

what does CFU mean

Answer 6

colony-forming unit

Question 7

where are lymphoid tissues found

Answer 7

1. Waldeyer’s ring
2. primary lymphoid organ
3. secondary lymphoid organ
4. Peyer’s patches
5. genitouniary tract

Question 8

what are primary lyphoid organs

Answer 8

thymus and bone marrow

Question 9

what are secondary lymphoid organs

Answer 9

1. adenoid
2. tonsil
3. lymph nodes
4. appendix
5. spleen

Question 10

key roles of primary lymphoid organs

Answer 10

1. lymphocyte development
2. enforcement of “tolerance” (removes self reactive lymphocytes)

Question 11

lymphoid precursors in bone marrow develop from what

Answer 11

hematopoietic stem cells

Question 12

when B cells complete development to mature in bone marrow, what do they become

Answer 12

“naive” B cells (not yet encountered antigen)

Question 13

T/F: in bone marrow, T cell precursors exit and migrate to thymus

Answer 13

TRUE

Question 14

T/F: T cell precursors arrive from bone marrow and complete their deelopment to mature “naive” T cells

Answer 14

TRUE

Question 15

what are the lobes of thymus

Answer 15

cortex and medulla

Question 16

what is densely packed w/ immature T cells underoging selection

Answer 16

cortex

Question 17

what contains fewer, more mature T cells that have survived selection and are more to be released into peripehry

Answer 17

medulla

Question 18

what are the parts you see on stained thymus

Answer 18

1. lobules
2. interlobular CT (septa)
3. cortex
4. medulla

Question 19

what are the key roles of secondary lymphoid organs

Answer 19

1. Trapping/concentration of antigen for presentation
2. Lymphocyte activation/proliferatio/differentiation
3. Enforcement of “tolerance” to antigens not seen in primary lymphoid organs

Question 20

what is the largest secondary lymphoid organ and pools/concentrates antigen from blood

Answer 20

spleen

Question 21

what is a small ovoid structure found in various regions and pools/concentrates antigen from tissues (via lymphatic vessels)

Answer 21

lymph nodes

Question 22

what lymphoid aggregates localized mucosal linings and pools/concentrates antigen that enterys via body cavities

Answer 22

mucosa-associated lymphoid tissue (MALT)

Question 23

what are examples of MALT

Answer 23

nasopharyngeal (NALT)
gut (GALT)

Question 24

what are the two main areas of the spleen

Answer 24

1. red pulp
2. white pulp

Question 25

what part of the spleen contains mostly red blood cells undergoing disposal

Answer 25

red pulp

Question 26

what part of the spleen contains lympod tissue

Answer 26

white pulp

Question 27

most T cells in spleen reside where

Answer 27

periarteriolar lymphoid sheath (PALS) surrounding central arteriole

Question 28

most B cells in spleen reside where

Answer 28

follicles within PALS

Question 29

lymphocytes enter lyph node via what and exits via what

Answer 29

enter: afferent lymphatic vessels of post capillary venules (high endothelial venules) exit: efferent lyphatic vessels (trafficks back into circulation)

Question 30

B cells of lymph node primarily found where? these contain what?

Answer 30

cortex arranged in follicles which may contain follicular dendritic cells that support rapid B cell

Question 31

T cells of lyph node primary found where? with what?

Answer 31

found in paracortex w/ antigen-presenting dendritic cells

Question 32

what part of nasopharygeal lyphoid tissues give ability for microvial oragnisms that enter nasal cavity

Answer 32

crypt

Question 33

lyphocytes enter reticulated epithelium via:

Answer 33

1. vascular - capillaries 2. vascular - high endothelial venules 3. nonvascular routes

Question 34

what is a term given to tonsillar crypt spithelium

Answer 34

lymphoepithelium

Question 35

what are the main components of tonsillary lymphoepithelium

Answer 35

1. microfold "M" cells (epithelial) 2. mucosal epithelial cells 3. infiltrating intraepithelial 4. intraepithelial vasculature

Question 36

what delivers antigen from luminal surface to underlying antigen presenting cells by transcytosis

Answer 36

microfold M cells

Question 37

what tonsillar lyphoepithelium is squamous or ciliated epithelial cells

Answer 37

mucosal epithelial cells

Question 38

what tonsillar lyphoepithelium contains mostly T cells

Answer 38

infiltrating intraepithelial lyphocytes

Question 39

what tonsillar lyphoepithelium containes intraepithelial cappillaries and HEVs in lower regions bordering basement membrance

Answer 39

intraepithelial vasculature

Question 40

composition % of tonsillar leukocytes

Answer 40

>50% B cells ~40% T cells balance macrophages and dendritic cells

Question 41

examples of tonsillar lyphoepithelium important route of pathogen entry

Answer 41

EBV, measles, prions, HIV

Question 42

what can be found in lymphoepithelium of gut

Answer 42

epithelial cell with surface microvilli, M cell, lymphocytes enfolded in M cell

Question 43

dendritic cells present antigen to what cells

Answer 43

helper T cells

Question 44

depending on the organism and environment which it was required, helper T cells release cytokines that orchestrate what?

Answer 44

appropriate immune response by B cells, inflammatory cells, or macrophages

Question 45

APC capture antigen in peripheral mucosal sites where? this facilitates what?

Answer 45

Antigen-presenting cells capture antigen in peripheral mucosal sites such as Payer's patch or tonsils and activate T cells, some of which can then facilitate B cell activation.

Question 46

T/F: in locations such as mucosal tissue and glands, some activated cells may traffic to a regional lymph node to enter circulation via thoracic duct, and migrate to distant mucosal effector sites

Answer 46

TRUE

Question 47

inflammatory cytokines relesased by immune cells activated by infection induce expression of what on where?

Answer 47

expression of intracellular adhesion molecules on endothelial cells (selectins and integrins)

Question 48

what acts as a chemo-attractant to circulating immune cells, like neutrophils, causing a conformational change in integrin to increase its affinity for its ligand

Answer 48

chemokines (e.g., interleukin-8)

Question 49

___ binding promotes adherence to enthothelium, but with high affinity ___ interactions, cell is stimulated to transit endothelium (diapedesis or extravasation)

Answer 49

selectin-selectin; integrin-integrin

Question 50

route of antigen exposure determines what

Answer 50

cell trafficking

Question 51

what are the different routes of antigen exposure

Answer 51

1. blood 2. tissue (epidermal, dermal or subcutaneous) 3. tonsils, Peyer's patches (oral route thru ingestion or breathing)

Question 52

lymphocyte trafficking for blood borne pathogens

Answer 52

spleen

Question 53

lymphocyte trafficking for skin

Answer 53

lymph nodes

Question 54

lymphocyte trafficking for mucosa

Answer 54

M cells at inductive sites, then to effector sites such as glands