Test 2: hemorrhage Flashcards
initial vessel wall constriction is cause by the release of — by platelets
thromboxane
transient vessel wall constriction is first cause by — and then by —
Thromboxane from platelets
prostacyclin from endothelial cells
— factor is required for platelet adhesion
von Willebrand’s factor
how does aspirin effect platelets
inhibits cyclooxygenase
prevents them from making Thromboxane- aggregation and vasoconstriction
they would only make prostacyclin which inhibits platelet activation and causes vasodilation
would need to hold Aspirin 5-10 days before procedure
Thromboxane causes
platelet aggregation and vasoconstriction
Prostacylcin causes
inhibits platelet activation and causes vasodilation
COX 1 or Cox2 expressed during inflammation
Cox 2
clotting factors are made by the
liver
which clotting factors are Vit K dependent
2,7,9 10
Vitamin K required for —
in the hepatocyte.
post-ribosomal carboxylation
vit K is fat soluble
how does rodent poison work
inhibit vit K epoxide reductase
intrinsic cascade is started by
contact of blood with foreign surface or damaged vessel wall
citrate inside blood bag will
bind to calcium and prevent clotting
extrinsic cascade is activated by
exposure to damaged
endothelium, extravascular tissue
Tissue thromboplastin complexes with and
activates factor VII which then activates the
final common pathway
Maximum activation of platelets occurs when they
are stimulated by both—
collagen and thrombin
As platelets accumulate, new platelets are blocked
from interaction with — so their surface
procoagulant activity decreases
collagen
factor 7a will trigger — to stop clots
Thrombomodulin
protein C
will inactivate Factor 5 and 8a
protein C will inactivate —
factor 8 and factor 5
— is used to break down clots
plasminogen
give — to greyhounds to prevent clots from breaking up too quickly
aminocaproic acid
Tranexamic
competes with fibrin for the lysine binding site of plasminogen/plasmin
tranfixation used for large vessels
“Obliterative” coagulation
Direct contact of electrode with vessel
– Thrombosis, coagulation of contracted tissue
“Coaptive” coagulation
Contact of electrode to hemostat on vessel
– Adventitia destroyed
– Smooth muscle dehydrated
– Intimal layers fuse
— is used from temporary occlusion of major vessels
clamps
rummel torniquets
