Immuno exam 2 - Lymphoid organs and lymphocyte tracking (chapter 7 pg 24-45)

what filters blood and breaks down old RBCs and recycles iron?

spleen

are there lymphatics bringing lymph to spleen?

no

blood entering spleen is diverted to what?

marginal sinuses (loaded with macrophages)

where does the spleen hold T cells?

PALS (periarteriolar lymphoid sheath)

where does the spleen hold B cells?

between PALS and marginal sinuses

hemoglobin broken down into

heme and globin

Heme breaks down into

bilirubin

globin breaks down into

amino acids

spleen holds a large number of monocytes which may migrate to battle sites to become what?

macrophages or dendritic cells

MALT in small intestine

Peyer's patches

what do peyer's patches contain?

HEVs and outgoing lymphatics

what cell allows the passage of cells into the GI tract?

M cells

what do M cells lack?

villi and mucus

how are peyer's patches much like other secondary lymphoid tissues?

Ag brought into distinct B and T cell areas

lymphocytes enter though HEVs

how are peyer's patches different from other secondary lymphoid tissues?

specialized in making helper T cells that tell B cells to make IgA Ab and that make Th2 cytokine profile

do all T or B cells that pass through a secondary lymphoid organ become activated?

no (only those that meet cognate Ag)

what happens to T or B cells that don't meet their cognate Ag?

leave and continue to circulate

naive T cells have many....

adhesion molecules

naive T cells circulate every _____ - _____ hours

12-24

what happens to naive T cells that do not meet their cognate Ag after about 6 weeks?

die via apoptosis

experienced T cells express......

certain adhesion molecules

adhesion molecules expressed by T cells depend on what?

where T cell was activated

peyer's patch activation site

a4b7 (gut specific so activated T cells in peyer's return to gut)

where do experienced T cells travel?

lymph organs where they were activated and site of infection

activated helper T cells in T cell areas proliferate and travel to ________ areas, activating _________

germinal B cell areas ; B cells

where do experienced B cells settle down? what do they do?

bone marrow ; make Ab