Week 5 Hemostasis Flashcards
What are the 3 steps of Hemostasis
- Vascular Spasm
- Platelet Blood Formation
- Coagluation
Vascular Spasm is …
Involuntary
Smooth Muscle
Happens w/in Seconds
the Vasoconstriction of a damaged vessle
Cold temperatures help smooth muscle do what
Cold temperatures help smooth muscle constrict
Hot temperatures work against and cause smooth muscle to dilate
How is surface area a factor in vascular spasm
When you cut with a sharp object there is less surface area making it harder to constrict
How quickly does platelet blood formation happen
Happens within minutes
Platelets are fragments from what
Megakaryocytes
Are platelets cells
No platelets are not cells they are fragments of megakarycocytes
What are platelets also known as
Thrombocytes
What do platelets do
Stick to collagen in the walls of vessels
What are the steps of platelets formation
- PLatelets stick to exposed collagen
- PLatelets degranulate (turn inside out) & Thromboxane A is released
- Thromboxane causes platelets to stick to other platelets which results in a platelet plug
What is Coagulation
Formation of blood clot
What is a Thrombus
a blood clot
What is an embolus
moving clot that can get stuck and cause an Embolism “clog”
Coagulation can take how long
Minutes and sometimes up to an hour
What are the requirements for Coagulation ( a blood clot)
Calcium in blood
Clotting factors - proteins involved in clotting
Vitamin K
Where is Vitamin K made
By bacteria in intesitnes
What are the 5 steps in Coagulation
- Damage Occurs
- Damaged Perivascular cells release Thromboplastin
- Plasma Proteins convert Thromboplastin into Prothrombin Activatior
- Prothrombin Activator converts Prothrombin into Thrombin
- Thrombin converts Fibrinogen into Fibrin
- Fibrin forms blood clot
Thromboplastin is normally found where
In Perivascular
True or False
Thrombin is normally found in blood
False thrombin is only found if there is damage
When is Prothrombin Activator found in blood
Only when there is damage
True or False
Prothrombin is always found in blood and is an inactive protein
True always found in blood
True is an inactive protein
True or False
Fribrinogen is always found in blood and is an inactive protein
True Fribrinogen is always found in blood and is an inactive protein
What are 2 inactive proteins always found in blood
Firbrinogen and Prothrombin
What does Fibrin do
forms blood clot by
trapping red blood cells
traps leukocytes WBCs
traps platelets
