Lecture 6 Flashcards
Hemostasis
all processes that minimize blood loss when a blood vessel is opened
includes 4 related events –> vasoconstriction, platelet plug, fibrin web, clot retraction/dissolution
Vasoactive amines
Serotonin
Histamine
Enzymes derived from plasma
blood coagulatoin cascade
Fibrinogen
soluble plasma protein that can be acted upon by clotting factors to ultimately form insoluble fibrin
a part of the plasma
Platelets
release serotonin
a part of formed elements
increased amount can cause venous thromboembolism
decreased amount can be infection, leukemia
Initial steps of hemostasis
Platelets and fibrinogen circulate in the blood
when a blood vessel is injured or ruptures, platelets release serotonin and aggregate to form platelet plug
Coagulation
processes by which liquid blood changes to a solid clot (thrombus)
uses platlets, RBC, fibrin
The platelet plug is not ___ ______ to curtail ____ _____
strong enough/blood loss
must be reinforced by solid strands of fribrin
Clotting factors
enzymes made by the liver
12 –> little a means that clotting factor is activated
Intrinsic Pathway
activation of complement proteins occurs within system
Extrinsic pathway
outside factor helps to activate the system
What protein do the intrinsic and extrinsic pathway come together?
10
Many complement proteins are _____ ______ dependent
vitamin K
can be found in diet or normal flora
Coagulation disorders
Too much BLEEDING
Too much CLOTTING
Coagulation disorders that result in deficient clotting
hemophilia A and B
von Willebrand disease
Hemophilia A
genetic deficiency in clotting factor 8
Hemophilia B
Christmas disease
genetic deficiency in clotting factor 9
Hemophilia A/B
most often these are x-linked recessive traits
treatment for both–> infusion of respective deficient clotting factors
von Willebrand disease
genetic deficiency or defective von willebrand factor
VWF = plasma protein that binds factor 8 and platelets
Functions of VWF
assists in formation of plug
helps initiate initial adhesion of platelets at sites of bleeding injury
binds and stabilizes clotting factor 8
treatment depends on severity
Fibrinogen is
SOLUBLE
Fibrin is
INSOLUBLE