lecture 14- vascular disorders 2

Question 1

failure of haemostasis can result in what?

Answer 1

failure of haemostasis can result in
-Haemorrhage 
Purpura; bleeding under skin
petechia (purple spot caused by bleeding into the skin)
haematoma; haemorrhage in a confined space 
haemorrhage into body cavities
haemopericardium (blood in pericardium)
-Thrombocytopenia 
deficient no. of platelets 
prolonged bleeding following trauma

Question 2

List the causes of haemorrhages

Answer 2

causes of Haemorrhage

• disruption of normal haemostasis
• blood vessels/ endothelial image (trauma)
• Thrombocytopenia (defective platelet function)
• Coagulation factor deficiency (inherited or acquired disorders)

Question 3

List the causes of thrombocytopenia

Answer 3

causes of thrombocytopenia
-failure of production (not producing any or enough)
radiation, drug toxicity, vaccination etc.
-increases destruction
primary immune mediated or secondary immune-mediated or alloimmune
-increased consumption (using up all your platelets) diffuse endothelial damage and platelet activation

Question 4

Explain some disorders of platelet

Answer 4

disorders of platelet 
prolonged bleeding 
normal platelet count
inability of platelets to adhere/ aggregate
inherited (von Willebrand disease)
acquired (uraemia)

Question 5

Explain coagulopathy

Answer 5

Coagulopathy
bleeding disorder due to deficiency of 1 or more coagulation factors
acquired or inherited disorder
excessive bleeding

Question 6

Discuss Disseminated intravascular coagulation

Answer 6

Disseminated intravascular coagulation (DIC)
secondary to severe disease
widespread consumption of platelets and coagulation factors

Question 7

For the evaluation of haemostasis explain the following
complete blood count
platelet count
platelet function tests

Answer 7

-Complete blood count; WCC (white cell count)
-platelet count (compare to normal levels)
-platelet function test
buccal (cheek) mucosal bleeding time
aggregometry (how well platelets clump together to form blood clots)

Question 8

For testing of plasma coagulation factors

• PT
• aPTT
• ACT
• TT

Answer 8

Test of plasma coagulation factors;
-prothrombin time (PT)
measure extrinsic and common pathway, detects deficiency of factor VII
-Activated partial thromboplastin time (aPTT)
measures intrinsic and common pathway, detects deficiency of factor VIII, IX, XI
-Activated clotting time (ACT)
less sensitive version of aPTT
-Thrombin time (TT)
measures deficiency of fibrinogen or stopping thrombin

Question 9

Discuss Arterial thrombosis

Answer 9

Arterial thrombosis
endothelial damage important for arterial thrombus formation
causes by trauma toxins etc.

Question 10

Discuss venous thrombosis

Answer 10

Venous thrombosis 
reduced/slowed blood flow 
aneurysms 
horses; intestinal torsion 
usually contain more erythrocytes than arterial thrombi