Lymphoid system and spleen Flashcards
where do B cells mature
bone marrow
where do T cells mature
thymus
what are primary lymphoid tissues
bone marrow and thymus
what are peripheral symphoid tissues
lymph nodes
spleen
tonsils (waldeyer’s ring)
epithelia-lymphoid tissues bone marrow
where do afferent channels of lymph node drain lymph to
through the collagenous capsule to peripheral sinus
where do efferent channels drain lymph to
thoracic duct
left or left jugular, subclavian or bronchomediastinal trunks
where does lymph enter venous system
left or right subclavian and jugular veins
what cells are contained in lymph nodes
B cells T cells NK cells mononuclear phagocytes (pre-macrophage) dendritic cells endothelial cells
what does CD20 make
B cells
what does CD3 make
T cells
causes of local lymphadenopathy
infection
vaccination
trauma
causes of systemic lymphadenopathy
infection
Autoimmune
what lymphoid cell is predominantly stimulated in auto-immune conditions
B cell
what lymphoid cell is predominantly stimulated in draining a tumour site
phagocytes
what cell is predominantly stimulated in viral infections and in response to phenytoin
T cell
which artery supplies the spleen
splenic artery
what is the splenic artery a branch of
coeliac
what vein drains the spleen
splenic vein
what supports the sinusoids of the spleen
hoops of reticulin
what cells do cords in red tissue contain
macrophages
some fibroblasts
some cells in transit
role of the spleen
act as a filter for the blood
clinical features of splenic enlargement
dragging sensation in LUQ
discomfort on breathing
pain if infarction
hyperslenism
what is present in lymphatic vessels to ensure direction of flow
valves
where do B cells lie in lymph node
follicles and germinal centre
where do plasma cells lie in lymph nodes
medulla
what happens in B cell response in a lymph node
enlarged follicles
what can cause general lymphadenopathy
inflammatory process
widespread malignancy
where does splenic vein drain to
superior mesenteric vein and splenic vein join to form portal vein
what are the different tissue types of the spleen
red pulp
white pulp
surrounded by a capsule
what does red pulp do
filter blood
action of white pulp
main immunological area - facilitates immune responses to blood borne antigens
what cells are contained in white pulp
T cells
arterial supply of spleen
splenic artery - trabecular artery - central artery inside spleen - radial arterioles to perilymphoid sinuses - pencillar arteries - sheathed capillaries
venous drainage of spleen
venous sinuses - trabecular vein - splenic vein
what comprises periarteriolar lymphoid sheath
CD4+ T helper cells
reasons for splenomegaly
infection (EBV, HIV, malaria, typhoid) congestion haematological diseases (lymphoma, leukaemia, haemolytic anaemia, MPD) autoimmune diseases storage diseases
what is seen after splenectomy
Howell-jolly bodies
target cells
