Haematology Flashcards
Define haemopoiesis
the physiological developmental process that gives rise to the cellular components of blood
What are the characteristics of a haemopoietic stem cell?
- differentiation potential for all lineages
- high proliferative potential
- long term activity throughout the lifespan of the individual
- self renewal
Describe symmetric self-renewal
Divide and produce 2 cells identical to itself:
increase stem cell pool, gives no differentiation of progeny
Describe asymmetric self-renewal
division into one stem cell and one progenitor:
maintain stem cell pool, generate differentiated progeny
Describe lack of self-renewal
division into two progenitors - generation of ONLY differentiated progeny
What lineage are granulocytes, erythrocytes and platelets all a part of?
myeloid
What lineage are B and T lymphocytes a part of?
lymphoid
When does haemopoiesis start?
day 27
Where is the origin of haemopoiesis?
aorto-gonado-medonephros
What are the functiosn of blood?
- oxygen transport
- coagulation
- immune response to infection
- immune response to abnormal cells
What is the lifespan of a RBC?
120 days in blood
Define anaemia
reduced red blood cells
What is polycythaemia?
raised red blood cells
What is relative polycythaemia?
when plasma volume is reduced (so RBC count is relatively higher)
What might cause neutrophilia?
bacterial infection or inflammation
What is the life span of a neutrophil?
6-8 hours in blood
What is a common cause of neutropenia?
certain drugs or in autoimmune disease
What might cause eosinophilia?
parasitic infections or allergies
What may cause basophilia?
chronic myeloid leukaemia
Describe monocytes
phagocytic and antigen presenting cells
Once monocytes migrate to tissues, what are they identified as?
macrophages or hsitiocytes
Describe natural killer cells
large granular lymphocytes that are part of the innate immune system
Which blood cells rearrange the immunoglobulin genes to enable antigen specific antibody production?
B-lymphocytes
When might you see lymphocytosis?
- atypical lymphocytes of glandular fever
- chronic lymphocytic leukaemia
