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24 Cards in this Set
- Front
- Back
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What is around the central artery |
T-lymphocytes forming the PALS
and B cells surroudning it that can become nodular and have a germinal centr |
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What is the role of the splenic cords |
cords are lined by macrophages and is a physical and functional filter for the blood
endothelial lining between the sinusoids and the cords is gapped allowing for intermovement |
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What is closed circulations |
arteries to capillaroes to splenic veins RAPID |
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What is open circulation |
arteries to capillaries to the cords then sinuses then veins
slow process
entire blood volume is cleaned once a day |
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What is the function of the spleen |
largest mononuclear phagocytic system, involved in all systemic inflammations generalized hemapoietic disorders, and many metabolic disturbances
Four major systemic splenic functions filtering/removal of unwanted or old peripheral blood ele immune response to blood born antigens source of hematopoiesis sequestration of blood elements |
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What are the elements of the splenic pathology |
usually presents as splenomegaly
my be resulting in cytopenias due to sequestration
early satiety due to pressure on stomach |
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How does the filtering and removal of unwanted elements lead to disease |
inability of RBCs to deform and pass from the splenic cords to sinusoids will result in their removal |
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What are accessory spleens |
spherical strucutres that are histo and functionally idential to spleen
can result in poor treatment for those who have their spleen removed and negates the benefit of the spleen
Removal of the spleen is to prevent unneccesary damage of the red cells |
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How does the spleen as an immune organ lead to disease |
Dendritic histiocytes response to antigens in the PALS and present to T lymphocytes resulting in an activated immune response
All blood borne infections result in splenomegaly can rupture as it is weak when enlarged |
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How does splenic rupture lead to death |
blood loss and shock |
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How does the spleen being a source of hematopoietic cells |
extramedullary hematopoiesis can be reactivated in the spleen when severe anemia occurs.
Primary myelofibrosis; myeloid neoplasm which grows too rapidly leading to scarring and inflammation can mess up the spleen |
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How does the sequestration of blood causes disease |
thrombocytopenia in patient with congestive splenomegaly due to portal hypertension usually resulting from cirrhosis of the liver |
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What is hypersplenism |
triad of splenomegaly, cytopenias: one or more of the three hematopoietic cell lines (erythroid, megakaryocyte, white cel line) is not on all cyldinders
correction via blood cytopenias by splenectomy |
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What is hypsplenism |
diminshed lethal syndrom characteriszed by diminished splenic function
asplenic blood = howell jolly bodies (usually removed by the spleen)
may lead to potential sepesis becaues infection is not being managed properly
sickle cell anemia is the most common disease associated with hyposplenism |
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What are splenic infarcts |
occlusion of splenic artery
may result from emboli that arise from thrombi in the heart or from atherosclerotic vascular disease |
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What is a splenic neoplasm |
are rare often involve the lymphohematopoietic system
when present causes splenomegaly |
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Splenomegaly due to |
infections
congestion
neoplasms lymphomas, myeloproliferative failure
immunolgic inflammatory disorders
storage disease
amyloid.. |
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What is Gachers disease |
unable to breakdown certain products, leading to phagocytosis in macrophages leading to growht in spleen |
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What is the thymic marker |
TdT terminal deoxynucleotidyl transferase, a marker of immaturity |
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What is thymic hypoplasia or aplasia |
DiGeorge syndrome accompanined by parathyroid development disorder |
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What is thymic follicular hyperplasia, |
applies to lymphoid follices in the thymus
leads to myasthenia gravis |
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Myasthenia gravis |
autoimmune muscle disease caused by immune mediated loss oc Ach receptors
thymic hyperplasia is seen in 65-75% of cases |
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What are thymomas |
a tumor of thymic epithelial cells
cna be benign or malignant
thymic carcinomas can be very aggressive and invade locally as well as metastatize
proliferating epithelila cells in a background of thymic lymphocytes
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What are the characteristics of thymomas |
in addition to MG what other immune disorders may be associated including pure RBC aplasia possibly due to abnormalities of T cell environemnt |
