The Spleen And White Cells Flashcards
What is red pulp in the spleen?
- sinuses linked with macrophages and cords
- The red cells move through it and old ones are recognised and phagocytosed
What is white pulp in the spleen?
- Similar to lymphoid follicles
- Many leukocytes and macrophages present
- plasma passes through and if checked for bacteria ect
What are the 4 key functions of the spleen?
- sequstration and phagocytosis of old RBCs
- Blood pooling (platelets and RBCs and then be mobilised when bleeding)
- Haematopoesis (if haematological stress/ bone marrow fails it has stem cells that can take over)
- immunological function (25% of t cells and 15% of white cells are here)
How can a spleen be palpated?
can never normally be felt
start palpation from right fossa or a large one might be missed
Measure its size from costal margin in mid clavicular line and downwards
What processes can cause splenomegaly?
- back pressure (portal hypertension in liver disease)
- overworking red or white pulp (haemolytic anaemias)
- if it starts haematopoesis
- cancers
- infiltration by other materials (gauchers or sarcoidosis)
What can cause a massive splenomegaly?
- chronic myeloid leukaemia
- myelofibrosis
- malaria
What can cause a moderate splenomegaly?
- lymphoproliferative disorders
- myeloproliferative disorders
- liver cirrhosis
- glandular fever (EBV infection)
What can cause a mild splenomegaly?
- Hepatitis
- endocarditis
- sarcoidosis
- autoimmune disorders
What complications are there to an enlarged spleen?
- if its enlarged its not protected by the spleen and so ruptures more easily leading to massive haemorrhage
- can also get pancytopenia due to blood pooling in the spleen
What causes hyposplenism?
splenectomy
sickle cell (causes many infarcts in spleen)
coeliac
What is seen on a blood film in someone with hyposplenism?
howell jolly bodies
- DNA remnant accumulations which look like red dots within cells
What is the difference between cytopenia and cytosis/ cytophilia ?
Cytopenia is decrease in the number of blood cells.
Cytophillia is increase
What is the name for a decrease in the number of WBCs?
leucopenia
What is the name for a decrease in the number of neutrophils?
neutropenia
What is the name for a decrease in the number of platelets?
thrombocytopenia