HEME PRACTICE EXAM 1
Erythropoietin (EPO) is produced by - ANSWER The kidneys
Normal levels of EPO - ANSWER 5-35 IU/L
EPO: Negative feedback mechanism - ANSWER EPO proxy is triggered
by DECREASED OXYGEN IN THE BLOOD (filtered through
the kidneys)
*EPO will then stimulate bone marrow to INCREASE RBC
PRODUCTION --> causes more RBCs = more O2 in the blood --> EPO
is then reduced
High EPO levels indicative of - ANSWER Iron deficiency of hemolytic
anaemia
- Decreased bone marrow proxy
- RBC destructions yield low Hemoglobin count --> decreasing O2 in the
blood
Low EPO levels indicative of - ANSWER Polycythemia vera
Renal DZ's
Primary hemostasis: 3 steps - ANSWER *@ site of vascular damage
(1) Platelet adhesion
(mediated by Von Willebrand factor & platelets to anchor to vessel walls
by binding to platelet receptors located in glycoprotein membrane)
(2) Platelet activation
(adhesion of platelets to vessel wall activates them, causing a change in
shape & activation of collagen receptor on the surface -- undergo
release reaction; platelets will synthesize & release thromboxane A2 &
PAF, platelet activating factor ==these are potent platelet aggregating
agonists & vasoconstrictors)
(3) Platelet aggregation
, (Thromboxane A2, PAF, ADH, & serotonin cause activation & recruit
additional platelets to bind to already adhered platelets --> this activation
is enhanced by generation of thrombin through coagulation cascade;
platelet aggregation is mediated primary by FIBRINOGEN --> binds to
glycoprotein IIb/IIIa) --> formation of the platelet plug is stabilized by
fibrin
Secondary hemostasis - ANSWER (stabilization of the clot)
*fibrin that anchors the hemostatic platelet plug --> formed from
fibrinogen by the action of thrombin
*Fibrin mesh is stabilized by covalent cross linking mediated by Factor
XIII
*coagulation cascade is separated into 3 pathways = intrinsic, extrinsic,
common pathways
What coagulation factors are Vit K dependent? - ANSWER 2, 7, 9, 10
Intrinsic pathway - ANSWER *helps to initiate clot formation in the
contact activation pathway
What does aPTT (activated partial thromboplastin time) measure? -
ANSWER *Intrinsic & common pathways
What does PT (prothrombin time) measure? - ANSWER Extrinsic &
common pathways
Mean red cell volume (MCV) - ANSWER *average volume/size of a
single RBC, used to classify anemias
High MCV - ANSWER Red cells are LARGE (macrocytic)
*Megaloblastic anemias (Vit B12 & Folic acid deficiencies)
*Liver disease
*Alcoholism
Erythropoietin (EPO) is produced by - ANSWER The kidneys
Normal levels of EPO - ANSWER 5-35 IU/L
EPO: Negative feedback mechanism - ANSWER EPO proxy is triggered
by DECREASED OXYGEN IN THE BLOOD (filtered through
the kidneys)
*EPO will then stimulate bone marrow to INCREASE RBC
PRODUCTION --> causes more RBCs = more O2 in the blood --> EPO
is then reduced
High EPO levels indicative of - ANSWER Iron deficiency of hemolytic
anaemia
- Decreased bone marrow proxy
- RBC destructions yield low Hemoglobin count --> decreasing O2 in the
blood
Low EPO levels indicative of - ANSWER Polycythemia vera
Renal DZ's
Primary hemostasis: 3 steps - ANSWER *@ site of vascular damage
(1) Platelet adhesion
(mediated by Von Willebrand factor & platelets to anchor to vessel walls
by binding to platelet receptors located in glycoprotein membrane)
(2) Platelet activation
(adhesion of platelets to vessel wall activates them, causing a change in
shape & activation of collagen receptor on the surface -- undergo
release reaction; platelets will synthesize & release thromboxane A2 &
PAF, platelet activating factor ==these are potent platelet aggregating
agonists & vasoconstrictors)
(3) Platelet aggregation
, (Thromboxane A2, PAF, ADH, & serotonin cause activation & recruit
additional platelets to bind to already adhered platelets --> this activation
is enhanced by generation of thrombin through coagulation cascade;
platelet aggregation is mediated primary by FIBRINOGEN --> binds to
glycoprotein IIb/IIIa) --> formation of the platelet plug is stabilized by
fibrin
Secondary hemostasis - ANSWER (stabilization of the clot)
*fibrin that anchors the hemostatic platelet plug --> formed from
fibrinogen by the action of thrombin
*Fibrin mesh is stabilized by covalent cross linking mediated by Factor
XIII
*coagulation cascade is separated into 3 pathways = intrinsic, extrinsic,
common pathways
What coagulation factors are Vit K dependent? - ANSWER 2, 7, 9, 10
Intrinsic pathway - ANSWER *helps to initiate clot formation in the
contact activation pathway
What does aPTT (activated partial thromboplastin time) measure? -
ANSWER *Intrinsic & common pathways
What does PT (prothrombin time) measure? - ANSWER Extrinsic &
common pathways
Mean red cell volume (MCV) - ANSWER *average volume/size of a
single RBC, used to classify anemias
High MCV - ANSWER Red cells are LARGE (macrocytic)
*Megaloblastic anemias (Vit B12 & Folic acid deficiencies)
*Liver disease
*Alcoholism
