W4: Haematopoiesis Flashcards
sites of Blood Cell Production
BM
BC maturation
BM + thymus
BC function
O2 transport - rbcs
immune defence - wbs
blood clotting - platelets
BC destruction
spleen
pos = neg selection in thymus
cortex = pos sel
cortex-medulla border = neg sle
primary vs secondary lymphoid organs
primary - site of immune cell prod + dev
secondary - site of lymphoid maturation, Ag entrapment + BC destruction
secondary lymphoid organs
lymphatic sys
spleen
MALT (mucosal associated lymphoid tissue)
peyers patch in small intestine
lymph travel where + collects where
lymphatic vessels
valves = lymph nodes
collects in thoracic duct
lymph nodes
submandibular
cervical
axillary
thoracic
abdominal
pelvic
inguinal
lymph nodes = site of
T and B activation + division
primary vs secondary lymphoid follicles (clusters of B cells)
primary = inactivated B cells
secondary = activated B cells
germinal centres
clusters of proliferating B-cells +T helper cells
B cells here multiply to PLASMA CELLS + secrete Abs to fight infection
what cells are in lymph nodes
lymphocytes
macrophages
dendritic cells (DCs)
3 zones of lymph nodes + cells they contain
cortex - inactive B lymphocytes
paracortex - Th cells
medulla - macrophages
spleen is site of
extramedullary haematopoiesis + BC prod - can be re-initiated
spleen projections on outer capsule called
trabecula
travel path of blood in spleen
enters via splenic artery
arteriole cords
white pulp
red pulp
re-enters circ into venous sinuses (blind ending veins)
splenic vein
white pulp surrounds ____ forming ____ containing which cells
splenic artery
periarteriolar lymphoid sheath
t lymphocytes
marginal zone of spleen contains which 2 cell types
B cells + macrophages
red pulp consists of
splenic sinuses + splenic cords
Mucosal associated lymphoid tissue (MALT) includes
tonsils
Peyer’s patches
appendix
lymphoid follicles in the intestines
lymphoid follicles in mucous membranes lining airways + genital tracts
tonsil structure
meshwork of reticular cells fibres interspersed w lymphocytes, macrophages, granulocytes + mast cells
tonsil function
defend against antigens entering through nasal + oral epithelial routes
peyers patch
The GI tract can endocytose antigen from the lumen where an immune response can be raised and antibody can be exported to the lumen
peyers patch (groups of lymphoid follicles)
lamina propria
submucosal layer
M cells
LP - B cells, plasma cells, activated Th, macrophages
SL - below LP - contains peyers patch
M - (microfold cells) lack microvilli + endocytose Ag from gut lumen
antigens in GI taken up by what cells + how + transported where
M cells by endocytosis + transported to lymphoid follicles
B cells in follicles differentiate to ___ + release ___ into gut lumen
plasma cells
IgA
stem cells divide into
myeloid progenitor
lymphoid progenitor
whats CFU
colony forming unit = a colony of cells generated from one progenitor cell
what are burst forming units (BFUs)
Burst forming units – a colony of cells that responds to erythropoietin to produce erythrocytes (in culture).
cell lifespans of
erythrocytes
neutrophils
t cells
platelets
120d
2-3d
20-30yrs
7-10d
differentiation depends on which 2 factors
growth factors
cytokines received by progenitor cells
Most haematopoietic growth factors are prod by BM ___ cells except for (2 things - prod where instead?)
stromal cells
Erythorpoietin – synthesised by kidney
Thrombopoietin – synthesised by liver
