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
what is pancytopenia
reduction in RBC, WBC and platelets
what gives more than 5 segments of a neutrophils nucleus
B12 deficiency
what hormone controls neutrophil maturation
G-CSF which increases neutrophil production
what can be administered to patients with neutropenia
recombinant G-CSF
what causes neutrophillia
infection, tissue damage, inflammation, cancer, myeloproliferative diseases, drugs
what is the neutrophil count in neutropenia
below 1.5x10*9
what results in an increased removal of neutrophils
- immune destruction
- sepsis
- splenic pooling
what causes a reduced production of neutrophils
- B12/folate deficiency
- infiltration of bone marrow
- empty bone marrow
- radiation
- drugs
- viral infection
what is an empty bone marrow called
aplastic anaemia
what are the consequences of neutropenia
- life threating bacterial and fungal infections
- mucosal ulceration
- neutropenic sepsis
what are monocytes
cells found in the blood which differentiate into macrophages when they reach the tissues
- involved in phagocytosis and pinocytosis in response to inflammation and antigenic stimuli
how long do eosinophils live
3-8 hours in circulation
8-12 days in tissues
what do eosinophils do
- destroy parasites
- mediator of allergic response
- phagocytosis of antigens
what causes eosinophilia
- allergic reactions
- drug hypersensitivity
- parasite infection
- leukaemia
- lymphoma
- myeloproliferative conditions
what are basophils
cells active in allergic response and inflammation
what do the granules in basophils contain
histamine, heparin, hyaluronic acid and serotonin
what causes lymphocytosis
- viral infections
- bacterial infections
- post splenectomy
- leukaemia
lymphoma
what causes an increased removal of cells to give pancytopenia
- immune destruction
- splenic pooling
- haemophagocytosis
what are the symptoms of pancytopenia
- RBC = fatigue, dizziness, chest pain, short of breath
- platelets = bruising, bleeding
- neutrophils = infection, ulceration, fevers
