Intro to Haematology Flashcards
What are the 4 main subdivisions of haematology in clinical practice?
- Coagulation
- Malignant
- Non-malignant
- Transfusion
What is haemopoiesis?
The physiological developmental process that gives rise to the cellular components of blood. A single multipotent haemopoietic stem cell can divide and differentiate to form different cell lineages that will populate the blood .
A stem cell can undergo different types of self-renewal. Explain these;
a) symmetric
b) asymmetric
c) symmetric differentiative/consuming
a) giving rise to two identical daughter stem cells
b) give rise to one stem cell and a more differentiated cell
c) generate two differentiated daughters
What are the first 2 sites of intraembryonic haematopoiesis?
1) Yolk sac
2) AGM (Aorto-Gonado-Mesonephros); a region of embryonic mesoderm
After the yolk sac and AGM, where does haemopoiesis then progress to?
- Hematopoietic stem cells migrate to the foetal liver,
* Then spleen and bone marrow (week 20)
What is extramedullary hematopoiesis?
Haematopoiesis occurring outside of the medulla of the bone (bone marrow). It can be physiologic or pathologic.
Physiologic EMH occurs during embryonic and foetal development; during this time the main site of foetal hematopoiesis are liver and the spleen.
What is pancytopenia?
A condition where a person has low counts for all 3 types of blood cells; RBCs, WBCs and platelets. This is usually due to a problem with the bone marrow.
Lifespan of erythrocytes?
120 days in blood
What is polycythaemia?
Raised levels of RBCs
What is relative polycythaemia?
An apparent rise of the erythrocyte level in the blood; however, the underlying cause is reduced blood plasma (hypovolemia, cf. dehydration). Relative polycythemia is often caused by loss of body fluids, such as through burns, dehydration, and stress.
What are granulocytes?
What 3 types of cells make up granulocytes?
A type of immune cell that has granules with enzymes that are released during infections, allergic reactions, and asthma. A granulocyte is a type of white blood cell.
1) Neutrophils
2) Eosinophils
3) Basophils
Which is the main granulocyte?
Neutrophils
What is the most common white cell in adult blood?
Neutrophils
What is neutrophilia? Caused by?
increased numbers of neutrophils
E.g. bacterial infection, inflammation
What is neutropenia? Caused by?
decreased numbers of neutrophils
E.g. side effect of drug (chemo)
What is eosinophilia? Caused by?
increased numbers of eosinophils
E.g. parasitic infection, allergies
What is basophilia?
What is it a hallmark of?
increased numbers of basophils
this is a hallmark of Chronic Myeloid Leukaemia
What are monocytes?
After they migrate to the tissue, what are they called?
Monocytes are the largest type of leukocyte.
Migrate to tissues & are then identified as “macrophages” or “histiocytes”
What are resident macrophages of the
a) liver
b) skin
known as?
a) Kupffer cells
b) Langerhans cells