Exam 2 - Chapter 7, secondary lymphoid organs

what are the primary lymphoid organs

bone marrow

thymus

what cells originate in the bone marrow?

b and t

where do t cells develop

thymus

what are the secondary lymphoid organs

lymph nodes

spleen

mucosal-associated tissue (MALT)

where are B and T cells activated

secondary lymphoid organs

what area of secondary lymphoid organs are T cells located in both the lymph node and spleen? where are B cells located?

lymph node: paracortex

spleen: PALS

b cells: lymphoid follicle

t/f

lymphoid follicles are within every secondary lymphoid organ

true

what cells occupy the primary lymphoid follicles?

follicular dendritic cells

naive B ells or memory b cells

when does a primary lymphoid follicle become a secondary lymphoid follicle (germinal center)

when B cells are activated

after there is antigen stimulation in the secondary lymphoid follicle, replication and differentiation of B cells takes place. What is this known as?

clonal expansion

a secondary lymphoid follicle is made of a light and dark zone, what cells make up each zone?

light: B cell, FDC

dark: proliferated B cells

what three processes of B cells occur in the Germinal center (secondary lymphoid follicle) following activation and proliferation

somatic hypermutation (dark zone), travel to light zone to test affinity

career decision (plasma or memory cell)

class switching (dark zone)

APDCs are WBCs made in ___ ___ and migrate to tissue to become ____. They then travel to ___ lymphoid organs and present antigen to ___ cells

bone marrow, activated, secondary, T

follicular dendritic cells (FDC) are regular cells that are in ____ lymphoid organs and display antigen to ___ cells

secondary, B

what is the normal function of FDCs

catch and display opsonized antigen to B cell

do FDCs kill or opsonize antigens

no, they just hold onto it

what receptors do FDCs have in order to bind to an opsonized antigen

complement and antibody

for B cell activation, what must be holding onto the antigen in order for a B cell to recognize it?

follicular dendritic cell

when the FDC holding an opsonized antigen comes in contact with a B cell, the B cell and antigen bind, B cell MHC II presents antigen to Follicular helper t cell, CD40/CD40L co-stimulation occurs and the B cell is ____

activated

MALT in the peyers patches and appendix is known as

GALT - gut associated lymphoid tissue

what components do Peyer's patches (GALT) have for lymphocytes to enter/exit?

HEV, efferent lymph vessels

what components do Peyer's Patches (GALT) have for antigen to enter?

m cells/microfold cells

what do M cells of the peyers patches do

enclose selective intestinal antigens in vesicles to release into surrounding tissue

in peyer's patches, helper t cells with ___ bias are made to tell B cells to make which antibody

Th2, IgA

MALT in the tonsils and adenoids are known as

NALT - nasal associated lymphoid tissue

MALT in the bronchi is known as

BALT - bronchus associated lymphoid tissue

describe the layers of a lymph node from outer to inner

capsule, subcapsular sinus/marginal sinus, cortex/B cell zone, paracortex, medulla, afferent and efferent lymph vessels

where does lymph first enter the node? what cells line this area

marginal sinus/subcapsular sinus

macrophages

what cells are found in the cortex of a lymph node

B cells and FDC

what cells are in the paracortex of lymph node

T cells

lymphocytes and antigens can enter a lymph node from what two ways? How can they exit?

HEV (blood) or lymph

exit via lymph

what components to lymph nodes have for lymphocytes and antigen to enter/exit?

afferent and efferent lymph, and HEV

an antigen entering the lymph node must be _____ in order for B cells and T cells to recognize it

opsonized

in a normal venule, endothelial cells usually have what appearance? how is it different in high endothelial venules?

shingle

cuboid = passage for cells

what is the immune function of the spleen

remove immune complexes (antibody + pathogen)

what components does the spleen have for lymphocytes and antigen to enter/exit?

efferent lymphatic vessels only

t/f

everything that enters the spleen is by blood

true

blood entering the spleen is shunted to the edges in an area called the ____ ____where it is filtered back to the ____ vein

marginal sinus, splenic

the spleen has a marginal sinus in its periphery, what cells are within this area

macrophages and resident APDCs

what do resident APDCs of the spleen display? what happens when they are activated?

MHC I and II

travel to PALS to activate T cells -> travel to lymphoid follicles of spleen to help B cells

what region of the spleen can you find T cells? where can you find B cells?

periarteriolar lymphoid sheath (PALS)

between PALS and Marginal sinuses

what process occurs in the spleen in response to encapsulated blood born bacteria

t cell independent b cell actication

which type of dendritic cell is part of myeloid lineage? which is part of lymphoid line?

classical APDC

resident APDC

macrophages of the spleen mediate generalized systemic inflammatory responses via which cytokine

TNF

the cholinergic anti-inflammatory pathway involves the ___ nerve regulating the amount of circulating ____ from macrophages to prevent a cytokine storm

vagus, TNF

the red pulp of the spleen is important for ___ function and the white pulp is for ___ function

blood, immune

does the spleen have more red or white pulp

red

what are the three regions that make up the white pulp of the spleen

PALS, Secondary Follicles, Perifollicular Zone

t/f

only t cells that meet their cognate antigen will be activated in the secondary lymphoid organs and the rest will continue to circulate to other secondary lymphoid organs

true

what do experienced t cells express to limit where they travel

adhesion molecules, specific to each region of body