Session 3 - Heamopoeisis and FBC Flashcards
where does heamopoeisis occur ?
the bone marrow
ribs, vertabrae, skull in adults
if bone marrow fails then the spleen can take up this function - extra medullary heamopoeisis
draw the heampoetic cell differentiation tree with all cells and key hormonal controls
check in session 3 lec 1
how is the control and removal of blood cells done ?
via the reticuloendothelial system (RES) - mainlt spleen and also the liver
kupfer cells in liver
langerhans cells in skin
microglia in the CNS
Red pulp macrophage in the spleen
what is the spleen’s strucutre and function ?
made of red pulp, removes old/abnormal red cells via phagocytosis
and white pulp - lymph system part - antibody detection and response - T and B lymphoctyes
it is supplied via the splenic artery
extramedullary heamopoeisis
blood pooling - blood pools in the spleen and provides as instant supply of blood in case of injury
outline the condition of an enlarged spleen
splenomegaly - growth of the spleen beyond normal
caused by portal hypotension in liver disease such as cirrhosis
thallasiemia or immunocompromised
a cancer or metastatis
liable to rupture and hence haemorrhage due to the enlarged spleen no longer being protected by the ribs - avoid certain activites - rugby, biking ect
you can also get infarction - squashed vessels from enlarging spleen
causes of splenomegaly
maybe try remeber 1 or 2 from mild moderate and massive
• Massive – chronic myeloid leukaemia, myelofibrosis, malaria, schistosomiasis
• Moderate – As above, PLUS lymphoma, leukaemias, myeloproliferative disorders, liver cirrhosis
with portal hypertension, infections such as Glandular Fever caused by Epstein Barr virus
• Mild – As above, also infections such as infectious hepatitis, endocarditis; infiltrative disorders such as
sarcoidosis; autoimmune diseases such as AIHA, ITP, SLE
• Low blood counts can occur due to pooling of blood in the enlarged spleen = hypersplenism
what is hyposplenism
how do we detect it
the lack of functioning splenic tissue
splenectomy, sickle cell disease, coeliac disease
Blood film will show howell jolly bodies - would be removed in a normal spleen, not in this case
people with this condition at risk of massive sepsis - of encapsulated bacteria - only the spleen deals with these - Pnemuococcus, Heamophilus Infulaenza, Menigococcus
what are the key proteins involved with red cell structure ?
Spectrin crosslinked via actin
held to membrane via ankyrin, band 3 and protein 4.1
glycoproteins and glycophorins A,B,C
explain the heamopiotic feedback loop in the ……… organ ?
occurs in the kidney
negative feedback loop
hypoxia (low o2) detected by cells within the kidney reduced o2 pressure is detected - due to decreased red cell count or reduced haemaglobin or ability to carry O2
Kindey releases the erythropoetin
stimulates bone marrow to make more RBC and mature them quicker
RBC released — O2 conc rises - detected and feedback loop stops
breifly how are red cells removed
RBC —-> Heme ——> Billirubin —- excreted in gut - if too much billirubin leak sinto tissues - jaundice
outline the names for low cell counts
Cytopenia is a reduction in the number of blood cells. It takes a
number of forms:
- Low red cell count = anaemia
- Low white blood = leucopenia
- Low neutrophil count = neutropenia
- Low platelet count = thrombocytopenia
- Low red blood cells, white blood cells, and platelets = pancytopenia
also basopenia, eosinopenia, lymphocytopenia, moncytopenia
outline the names for raised cell counts
- high red cell count = erythrocytosis
- high white blood = leucocytosis
- high neutrophil count = neutrophilia
- high lymphocyte count = lymphocytosis
- high platelet count = thrombocytosis
also lymphocytosis, monocytosis, eosinophillia, basophillia,
All - panmyelosis
what is the significance of a high reticulocyte count ?
high reticulocyte count implies large amounts of new RBC being made as reticulocytes are new RBC’S
this tells us for some reason body is making more RBC
look over in the workbook the names for abnormal cell appearance , you do not need to memorise these but understand and be familiar with them
do it
outline the types of immune cells and their roles
neutrophil - lobulated nucleus - controlled by G-CSF - we can administer this to boost neutophil count - ie in a neutropenia - increased removal or use - spesis, immune destruction, splenic pooling or reduced production - caused by B12/folate deficiency, chemo/ viral infections damages marrow
neutropenic sepsis is a medical emergency - give IV antibiotics ASAP
neutrophillia - raised - due to an infection, cancer, tissue damage
neutrophlils migrate via chemotaxis to site, and use phagocytotic respiratory burst to kill pathogens
basophil - allergic reactions and inflammatory conditions - hypersensitivity reactions cause high counts
eosinophil - mediator of allergic response, kill parasites, asthma, drug hypersensitivity
lymphocyte - T (CD4+ and CD8+) and B and natural killer cells - high count due to viral or bacterial infections
monocytes / macrophage - engulf organisms and present antigens for immune system - infection, cancer ect
check roles in session 3 lec 1
