DUMS powerpoint- the science and spleen Flashcards
terminilogy- philia/ cytosis?
too much
thrombophilia meaning?
too much clotting
thrombocytosis meaning?
too many platelets
terminology- penia?
too little
terminology- dys?
abnormal growth
life span of red cells?
120 days
how many red cells are lost/ produced per second?
2.5 million red cells are lost/made per second
life span of platelet?
life span of platelet is 7-10 days
how many platelets are made per second?
1 million platelets are made every second
average lifespan of neutrophils?
life span of neutrophils is 7-8 hours
how many neutrophils are made/ destroyed every second?
1-2 million neutrophils are made/destroyed every second
how are platelets formed?
from the budding of a megakaryocyte
Explain how erythrocytes and platelets are produced from stem cells
- LT-HSC (stem cell)
- ST-HSC (stem cell)
- MPP (multipotent progenitors)
- CMP (common myeloid progenitors)
- MEP (megakaryocyte erythroid progenitor)
- Erythtrocyte or platelet
Explain how B lymphocytes, T lymphocytes and NK cells are produced from stem cells
- LT-HSC (stem cell)
- ST- HSC (stem cell)
- MPP (multipotent progenitor)
4.CLP (common lymphoid progenitor) - Pro T, Pro NK or Pro B
- T cells, NK cells, B cells
explain how granulocytes and macrophages are produced from stem cells
- LT-HSC (stem cell)
- ST-HSC (stem cell)
- MPP (multipotent progenitors)
- CMP (common myeloid progenitors)
myeloblast?
- GMP (granulocyte monocyte progenitor)
- Macrophage or granulocyte
what is the role of neutrophils?
play a role in acute inflammation
name the 3 granulocytes
neutrophils
Eosinophils
Basophils
what do neutrophil granules contain?
Lysozyme and myeloperoxidase
Role of eosinophils?
-Defend against parasites (protozoan and helminthic infections)
-Play a role in allergy
what colour do eosinophils granules stain?
red/pinky/orangey
what colour do neutrophils granules stain?
‘neutral’ pink granules
what colour do basophils granules stain?
blue/ purpley granules
what role do Basophils play?
-play a role in IgE mediated reactions (e.g. type 1 hypersensitivity reaction which would be an allergic reaction that occurs immediately)
Explain how RBC are made in response to hypoxia
-Hypoxia sensed by hypoxia sensor in kidney
-EPO (erythropoiten) produced by the kidneys
-EPO stimulates RBC production
-EPO drops and this process is repeated
where are RBC broken down and how?
Most are broken down in the spleen
-Globin is broken into amino acid chains
-Haem is recycled into iron + bilirubin, the bilirubin is taken to the liver to be conjugated and excreted as bile (this colours the urine and faeces)
where is blood made as a foetus?
haemopoietic stem cells originate in mesoderm
5 weeks- circulating progenitors are detectable
starts at 6 weeks- liver
until 10th week- Yolk sac
3rd- 7th month- spleen
starts at 16th week- bone marrow
where is blood made at birth?
-mostly bone marrow
may still be producing from liver and spleen if needed
where is blood made as an adult?
bone marrow in the axial skeleton (skull, ribs, sternum, pelvis and proximal femur)
where do you get bone marrow biopsy from adult and young child?
adult= iliac crest/ sternum
child= tibial marrow cavity
what are the types of marrow and which is active/ inactive?
Red marrow= active
Yellow marrow= inactive
what is red marrow Vs yellow marrow made of?
red marrow= haemopoietically active
-contains blood stem cells that can become RBC, WBC or platelets
yellow bone= fatty and inactive
-contains stem cells that can become cartilage, fat or bone cells
what pulp is in the spleen?
Red pulp and white pulp
what is the red pulp in the spleen?
Red pulp contains:
-sinusoids (vascular part)
-cords (contain macrophages to break down RBC)
It is basically a vascular sieve
-phagocytosis old RBCs and breaks them into iron and bilirubin
what is the role of white pulp in the spleen?
IMMUNOLOGICAL RESPONSE
the white pulp contains PALS (periarterial lymphoid sheath)
-this contains T and B cells which react with antigens on antigen presenting cells in the blood
splenomegaly presentation?
triad of:
-Dragging LUQ sensation
-discomfort eating
-pain (secondary to infarction)
what is moderate splenomegaly in the Western world most often due to?
In the western world splenomegaly is most often due to portal hypertension or blood disease
what is hypersplenism?
-Splenomegaly
-Fall in 1 (+) components in blood
-Cytopenia fixed by splenectomy
what are causes of splenomegaly?
Increased function, increased blood flow and cancerous infiltration
-Increased function: haemolysis, infection (mononucleosis), autoimmune disease (RA), extramedullary haematopoiesis
-Increased blood flow: portal hypertension
-Cancerous infiltration: leukemia, lymphoma, myeloproliferative
what is Felty’s syndrome?
important cause of splenomegaly!!
-infective endocarditis, RA + low WBC
most common cause of hyposplenism?
splenectomy
causes of hyposplenism?
-splenectomy (most common)
-sickle cell disease
-coeliac diease
-sarcoidosis
-iatrogenic
blood film of someone with hyposplenism?
Abnormal red cells as vascular sieve is lost
what are indications to splenectomy?
-splenic trauma (very vascular)
-hypersplenism
-AI haemolysis
what spleens are more susceptible to truama?
diseased spleens are more susceptible to trauma
what is seen in the blood film after splenectomy?
Howell Jolly Bodies, target cells
why is there pancytopenia in hypersplenism?
as the cells get trapped in the spleen (reticuloendothelial system)
what are Howell- Jolly bodies?
remnants of RBC nuclei that are normally removed by the spleen
what do target cells look like?
‘Mexican hat cells’
-central staining, ring of pallor and peripheral staining
how long do you have to avoid contact sport after EBV and why?
avoid contact sport for 2 months after EBV (Regardless of whether theres splenomegaly or not)
-as diseased spleens are more susceptible to trauma
what are you at increased risk of by doing a splenectomy?
-Hyposplenism (splenectomy is most common cause of hyposplenism)
-Increased lifelong infection risk from encapsulated organism (strep pneumoniae, H influenzae, menningococcus)
how can you reduce the risks of lifelong infection from splenectomy?
using immunisations and prophylactic antibiotics
