Coagulation Science

Question 1

Components

Answer 1

Vascular reaction
Primary heamostaisi
Secondary haemostats
Fibrolysis

Question 2

Vascular Damage

Answer 2

Vessels constrict
Release of procoagulant factors
Release of anticoagulant factors
Provides a surface for platelet activation and aggregation

Question 3

Primary Haemostatis

Answer 3

Platelet adhesion
Alteration in platelet shape
Activation, release of platelet granule contest - degranulation of attractants
Aggregation of platelets

Question 4

Secondary Haemostatis

Answer 4

Most proteins involved in secondary haemostats are serine proteases
Serine proteases = enzymes that cleave peptide bonds in other proteins
Cascade mechanism - activation of 1 serine protease, will then activate the next
anti - coagulant factors - make up secondary haemostatsis, coagulation cascade to form a stable fibrin clot

Question 5

Vitamin K

Answer 5

Is essential for production of serine proteases active in secondary haemostats
It is involved with the post - translational modifications of these proteases to enable their function
Serine. proteases linked to vitamin K action are - Factor II, Factor VII, Factor IX, Factor X, Protein C

Question 6

Secondary haemostatis - coagulation cascade

Answer 6

Extrinsic pathway - tissue damage
Intrisinc pathways - surface contact
Common pathway

Question 7

Physiologicsl inhibitors of coagulation cascade (anticoagulants)

Answer 7

Antithrombin - principle physiological inhibitor of activated coagulation serine proteases

Question 7

Physiologicsl inhibitors of coagulation cascade (anticoagulants)

Answer 7

Antithrombin - principle physiological inhibitor of activated coagulation serine proteases

Question 8

Firbinolysis

Answer 8

Degradation and dissolution of formed fibrin clots
requires fast and localised effect

Question 9

Main components of fibrinolysis pathway

Answer 9

Plasminogen activators - intrisinc and extrinsic
Plasminogen and plasmin - strong affinity for fibrinogen and fibrin
Inhibitors of fibrinolysis

Question 10

Platelet Disorders

Answer 10

Qualitative - normal number but abnormal function
Quantitative - abnormal number, thrombocytosis - too many, thrombocytopenia - not enough

Question 11

Thrombocytopenia

Answer 11

Low platelets can be seen in following conditions - post surgery, post chemotherapy, server infection

Question 12

Thrombocytosis

Answer 12

Reactive to - blood loss, iron deficiency, post surgery

Question 13

Primary Causes

Answer 13

Disorders of platelet adhesion or aggregation
Reduced numbers

Question 14

Essential Thrombocythaemia

Answer 14

Myeloproliferative disorder
Must be closely monitored and treated
2-3 diagnosed per 100,00 annually

Question 15

Secondary causes - far more common

Answer 15

Reactive - post - op infection
Drug induced - chemotherapy, heparin induced thrombocytopenia (HIT)
Hepatic disease - Thrompoeitne
, synthesis of coagulation factors

Question 16

Condition’s associated with bleeding disorders

Answer 16

Liver disease
Renal disease
Pregnancy
Drug related
Immune complexes

Question 17

Disseminated intravascular coagulation (DIC)

Answer 17

DIC is a common complication of a wide range of disorders
A DIC can be triggered by a combination of three mechanism

Question 18

Haemorrhagic Disorders

Answer 18

E.g. Von Willebrand Disease (vWD)