Haematology Flashcards
What is the lifespan of an RBC?
120 days
What are the 3 types of granulocytes?
Basophils, eosinophils, neutrophils
What is an immature RBC in the blood stream called?
Reticulocyte
What is the average lifespan of a platelet cell?
8-10 days
What shape is the nucleus of a monocyte?
Kidney /bean shaped
What is the diameter of a platelet cell?
2-4 um
What is the diameter of an RBC?
7.2 microns
Which is the most abundant WBC?
Neutrophil
What’s the most important FBE index to determine the cause of an anaemia?
MCV (mean corpuscular volume)
A patient with microcytic anaemia and low ferrettin has what?
Iron deficiency anaemia
What are the two main causes of microcytic anaemia?
Iron deficiency and thalasaemia
If someone has normocytic anaemia, what is the next test you should look at?
Ferretin to see if it is due to iron deficiency or thalasaemia
What are the 4 main causes of normocytic anaemia?
Acute blood loss Bone marrow failure Chronic disease Destruction (haemolysis)
Normocytic anaemia with low reticulocyte count suggests what?
Bone marrow failure - bone marrow can’t produce enough new RBCs to keep up with anaemia
Deficiency of what in the diet will cause macrocytic anaemia?
Folate and B12
If there is a normocytic anaemia, what is the next test result you need to look at?
Is there reticulocytosis (to see if bone marrow is working)?
If there is a macrocytic anaemia, what is the next test result you need to look at?
Is it megaloblastic?
What is haematocrit?
Percentage of blood volume that is RBC volume
What type of WBC is this?
Basophil
What type of WBC is this?
Neutrophil
What shape is the nucleus of a monocyte?
Kidney /bean shaped or eccentric oval
Which WBC has a bilobed nucleus?
Eosinophils and basophils
Which WBC has a kidney-shaped nucleus?
Basophils OR Monocytes
What type of WBC is this?
Eosinophil
What type of WBC is this?
Basophil
What type of WBC is this?
Monocyte
A raised neutrophil count indicates what?
acute inflammation, especially seen in bacterial infections
What type of WBC is this?
Monocyte
What type of WBC is this?
Neutrophil
What type of cell is this?
Lymphocyte
What is the diameter of a WBC (neutrophil)?
1-2x that of a RBC; 10-14 um
What type of blood cell is this?
Megakaryocyte
What type of WBC is this?
Neutrophil
What type of WBC is this?
Eosinophil
What type of WBC is this?
Monocyte
Which WBC has a multil-lobed nucleus?
Neutrophils
What type of WBC is this?
Monocyte
Which is the largest WBC?
Monocyte
What type of WBC is this?
Basophil
What type of WBC is this?
Eosinophil
What type of WBC is this?
Neutrophil
Which is the most abundant WBC?
Neutrophil
What type of cell is this?
Neutrophil
How long after entering tissue until neutrophils die?
Within hours
Describe laminar blood flow and the relative positions of WBCs, platelets and RBCs
Larger components of blood are in centre of lumen, thus WBC > RBC > platelets from centre to periphery.
In what form does Hb carries about 15% of its respiratory carbon dioxide?
carbaminohaemoglobin
What percentage of respiratory carbon dioxide does Hb carry as carbaminohaemoglobin?
15%
Name three factors that can shift the O2 saturation curve to the right
Increased DPG Increased temperature Decreased pH
What is APTT
Activated partial thrombin time
What percentage of red blood cell dry content does Hb make up?
97%
What makes up about 97% of red blood cell dry content?
Hb
List 5 acute signs of hypovolaemia
Tachycardia
Hypotension
Cold/clammy skin
Poor capillary refill (> 2 secs)
Tachypnea (if severe hypovolaemia)
Why does Hb carry nitric oxide bound to a globin thiol group? And when does Hb release it?
It rrelaxes vascular walls and enhance gas diffusion. Hb releases NO at the same time as oxygen.
What effect does shifting the O2 saturation curve to the right have on Hb affinity for O2?
Decrease
Describe 5 steps in secondary haemostasis
1 vessel damage releases tissue factor 2 extrinsic pathway: parathrombin → thrombin, 3 fibrinogen to fibrin, 4 fibrin crosslinks under factor XIIIa control 5 meshwork
What are the 3 components of Virchow’s triad of thrombosis?
Vessel wall Blood composition Blood flow
What is the descending order of WBC concentrations in the blood?
NLMEB
What is the molecular target of warfarin?
Vitamin K reductase
Inhibition of this prevents reduced VitK acting as a cofactor for activation of factors 2, 7, 9 and 10
What percentage of the blood is in the arteries?
13%
Which factors does warfarin inhibit?
2, 7, 9, 10
Describe 4 steps in primary haemostasis
1 Vessel damage exposes von Willibrand factor on basement membrane and collagen 2 vWF binds to Gp1b on platelets 3 Platelet: adhere, flatten, recruit, degranulate (ADP and thromboxin A2) 4 platelet plug
What percentage of the blood is in the heart?
7%
What percentage of the blood is in the capillaries?
5%
What is INR and how is it calculated?
International normalised ratio INR = (patient PT/normal PT)^ISI INR = (Patient prothrombin time/mean normal prothrombin time)^international sensitivity index
What effect does shifting the O2 saturation curve to the left have on Hb affinity for O2?
Increase
What percentage of the blood is in the lungs?
10%
What percentage of the blood is in the veins?
65%
A raised INR indicates which 2 possible things?
There is a problem with Factor VII or the patient is on warfarin
Define anaemia and which two blood tests are used most often in diagnosis
A reduction of the total circulating red cell mass below normal limits.
Haematocrit and haemoglobin concentration
Dietary deficiences of which 3 substances may cause anaemia?
Iron, VitB12, folate
Define embolus
Intravascular mass carried in the blood stream to a remote site. May be solid, liquid or gaseous
Name three factors that can shift the O2 saturation curve to the left
Decreased DPG Decreased temperature Increased pH
What are the constitutive subunits of Hb in adults and foetuses?
Adults: 2 alpha and 2 beta Foetuses: 2 alpha and 2 gamma
What is the molecular target of heparin?
Heparin enhances activity of antithrombin III, which inhibits factor Xa and thrombin
What are the 3 main components of the coagulation system?
Vasoconstriction, platelet plug and fibrin mesh
Name 3 vasoactive agents that endothelium releases and describe their effect on vasculature
Vasoconstrictor: endothelin
Vasodilator: NO and prostacyclin (PGI2)
List 5 factors that may affect the effects of warfarin
Diet (VitK)
Hepatic disease
Hypermetabolic state
Pregnancy
Drug interactions, eg NSAIDs, EtOH
What converts fibrinogen → fibrin?
Thrombin
Which factors is vitamin K a co-factor for?
2, 7, 9, 10
ie the same cofactors that warfarin affects
What is the most abundant protein in blood plasma?
Serum albumin
