Spleen, WBC and Cytopenia Flashcards
what does the spleen consist of
red pulp and white pulp
what is red pulp
sinuses lined by endothelial macrophages where RBC are filtered
what is white pulp
lymphoid follicles which give an active immune response due to their large amounts of B and T lymphocytes
why can you get weight loss with an enlarged spleen
the spleen pressures of the stomach so it cant expand fully making you feel fuller easier
give 4 functions of the spleen in adults
- phagocytosis of old RBC by macrophages
- blood pooling (platelets and RBCs can be mobilised rapidly)
- extramedullary haemopoiesis
- immunological function
what causes splenomegaly
- portal hypertension
- overworking red/white pulp
- extramedullary haemopoiesis
- infiltrating cells (cancer or granulomas)
what are the causes of massive, moderate and mild splenomegaly
massive = leukaemia, myleofibrosis. malaria moderate = portal hypertension, glandular fever mild = hepatitis, endocarditis, sarcoidosis
what is hypersplenism
where pancytopenia or thrombocytopenia cause pooling of the blood giving an enlarged spleen
what are the complications of splenomegaly
- rupture to form a haematoma
- parts of the spleen can be cut off from the blood supply causing areas of infarction
what is hyposplenism
lack of functioning splenic tissue
what causes hyposplenism
- splenectomy
- sickle cell
- coeliac
what is seen histologically in hyposplenism
Howell Jolly Bodies (parts of DNA)
what 3 organisms are people with hyposplenism particularly at risk of developing sepsis from
Pnemococcus, Haemophilius influenza and Meningococcus
what is cytopenia
reduction in the number of blood cells
what is leucopenia
reduction in WBC