Haematology Flashcards
(23 cards)
What are the components of blood?
Plasma
Formed elements
- Red cells, White cells, Platelets
- Granulocytes, Agranulocytes
- (g) Neutrophils, Eosinophils, Basophils
- (a) Lymphocytes, MonocytesWhat do red cells do?
Transport O2
What do white cells do?
Fight infection
What do platelets do?
Prevent bleeding
Where is the site of production of blood cells for the majority of human life?
Bone marrow
Do red cells have a nucleus?
No, the have Hb instead
What is Hb?
an iron containing protein with a haem group
What does lack of iron lead to?
A reduction in Hb
What is there a reduced totally mass of in anaemia?
There is a reduced total red cell mass
What do blood films do?
They are used to confirm the abnormalities identified by analysers.
When is there an increase in neutrophils?(granulocytes)
Stress - physiological or pathological (acute inflammation, trauma, infarction)
Steroids - (cause de margination) - increases neutrophil count, changes localisation of neutrophils, they go from the edge of the vessel to the midline, so when you take a sample there are more neutrophils, however the actual number of neutrophils does not go up.
When is there an increase in eosinophils?(granulocytes)
Parasitic infection
Hypersensitivity reaction
When is there an increase in basophils? (granulocytes)
Hypersensitivity reactions
When is there an increase monocytes? (white cells)
Chronic infections, malignancy, autoimmune disorders
When is there an increase in Lymphocytes? (white cells)
Viral infections etc
What is haemostasis?
The arrest of bleeding and the maintenance of vascular patency - the link between platelets and plasma
What are the requirements of haemostais?
Premenant state of readiness
Prompt response
Locaslied response
Protection against unwanted thrombosis
What are the components of normal haemostatic system?
Formation of the platelet plug - primary haemostasis
Formation of fibrin clot - secondary haemostasis
Fibrinolysis - anticoagulant defences
Describe the platelet structure and function?
- Small anucleate disc with a mean life span of 7-10days
- Damage to endothelial cells exposes collagen
- Platelet adhesion occurs at the site injury
there is then secretion of various chemicals from the platelets which leads to aggregation of platelets at the site of injury
Give examples of high and low platelet diseases?
High - acute blood loss, iron deficiency
Low - liver disease, rapid consumption
What is fibrin clot formation, secondary haemostasis?
Series of reactions involving activation of coagulation factors to an active state (pro-enzyme to enzyme), that results in the conversion of soluble fibrinogen into insoluble fibrin
Describe D dimers?
Fibrin degradation product
If increased it suggests increased fibrinolysis (breaking down a clot)
Could be raised in abnormal thrombus
What is plasma viscosity an index of?
changes in plasma proteins (fibrinogen and some globulins).
- can reflect systemic inflammation
