Bone marrow and blood cells Flashcards
Where does haemopoiesis occur in the fetus, and adult?
Fetus:
yolk sac
liver are spleen
bone marrow
Adult:
bone marrow - vertebrae, ribs, sternum, sacrum and pelvis, proximal femur
What are the parts of bone marrow and what do they produce
red marrow - haemopoietic tissue - RBC, platelets, white blood cells
Yellow marrow - fatty tissue
What are reticulocytes? When are they increased?
Young larger RBCs
signify active haemopoiesis
Increase in haemolytic or if B12, iron or folate is given in their deficiency
What cells do platelets come from?
Megakaryocytes
What are functions of the spleen?
Sequestration and phagocytosis of old and abnormal red blood cells
Immunological - lots of B and T cells present - produces antibodies
Blood pooling so that RBC and platelets can be mobilised rapidly in bleeding
Extramedullary hawemopoiesis durin stress
What causes splenomegaly?
Infections - hepatitis, endocarditis Sarcoidiosis Autoimmune haemolytic anaemia SLE Leukaemia Liver cirrhosis
When is there hyposplenism? What are the risks? What must be done for this?
Sickle cell disease
Coeliac disease
Splenectomy
Sepsis from encapsulated organisms - streptococcus, staphylococcus, haemophilus influenza, neisseria meningitises
Penicillin V prophylaxis and vaccination
What causes thrombocytopenia?
Reduced production: B12 and folate deficiency - required for DNA synthesis Aplastic anaemia - bone marrow failure Drugs: chemotherapy Viruses : HIV
Increased removal:
Non-immune - Thrombotic thrombocytopenia purport, DIC - pathological activation of coagulation - microthrombi are formed in the ciruculation consuming clotting factors and platelets, and the travell of blood cells through damaged vessels leads to haemolytic.
Immune desctruction - immune thrombocytopenia purpura - antibodies against
What is the presentation of thrombocytopenia?
Easy bruising Petechiae and purpura - red/purple non blanching spots Mucosal bleeding Severe bleeding after trauma Intracranial haemorrhage
What causes neutropenia?
B12/folate deficiency
Malignancy
Aplastic anaemia
Drugs: chemo, abx, DMARDs, clozapine, carbamazepine
Increased removal:
Immune descrtruction
splenic pooling
What do neutrophils do? symptoms of neutropenia?
Increase during infection
Ingest and destroy pyogenic (pus forming) battersia - staph, strep
Recurrent infection
ulcers
fevers
What causes pancytopenia?
Increase removal - immune destruction, splenic pooling
Reduced production: B12/folate deficiency Malignancy - leukaemia, myeloma Immuna aplastic anaemia Drugs - chemo, DMARDs Viruses
