Secondary Lymphoid Organs Flashcards
What are the 2 primary lymphoid organs
Bone marrow
Thymus
where do B and T cells originate
Bone Marrow
where does the T cells develop
Thymus
What are the secondary Lymphoid organs
Lymph Nodes
Spleen
MALT
what does MALT stand for
Mucosal-Associated lymphoid tissue
Which lymphoid organs are Lymphoid follicles associated with
all of them
what is the make up of a primary lymphoid follicle
- loose network of FDCs
- rich in naive B cells (or memory cells)
what does FDC stand for
Follicular Dendritic Cells
what is the make up of a secondary lymphoid follicle
- after antigen stimulation
- turns into a Germinal Center
Where are dendritic cells made
in the bone marrow and migrate to tissues
which cells are APC
B-cells, Macrophages, Dendritic Cells
Who do FDCs present their “caught” antigen to
B-cells
What binds to invaders so DCs recognize the antigen
Complement proteins and antibodies
FDCs have receptors that bind to what
- complement proteins
- FC region of antibodies
how does the FDCs make a signal strong enough to activate a B cell
they cluster their opsonized antigens together
What causes a Follicle to turn into a Germinal Center
B cells activate and proliferate (doubling every 6 hours) creating a dark zone
When some B cells in the germinal center decide to become plasma cells where do they go
Bone Marrow
what process allows B cells to fine tune the Fab regions of their antibodies
Somatic Hypermutation
New mutations of B cells in the germinal centers are tested where
in the Light Zone
class switching of antibodies in the germinal center are likely to occur where
in the Dark Zone
T/F secondary lymphoid organs do not have seperate areas for naive T cells and naive B cells
False
once Helper T cells are activated they migrate where
the to B cell area to help activate the B cells
How can antigens enter lymph nodes
the blood or lymph
how do lymphocytes leave the blood and enter the lymph node
via HEV
