Chapter 22: Disorders of Hemostasis Flashcards
Why should blood clot?
Hemostasis is designed to maintain the integrity of the vascular component
What are 5 stages of hemostasis?
- Vessel spasms
2.Formation of the platelet plug - Blood coagulation or development of an insoluble fibrin clot
4.Clot retraction
5.Clot dissolution
**Categories of Disorders of hemostasis
What is thrombosis ?
Blood clot inappropriately forms within veins or arteries
**Categories of Disorders of hemostasis
What is bleeding?
Blood fails to clot and result in excessive bleeding
What is vascular constriction?
-Spasms which is transient
-Last minutes to hours
-Initiated by endothelial injury
What is platelet plug formation?
Adhesion and aggregation of platelets
1. Platelets are attracted to damaged vessel wall
2.Attraction is activated by subendothial tissue
3.Platelet will change from smooth disks to spiny spheres so they are able to clump together
4. They will expose glycoprotein receptors to their surfaces
What are requirements for blood to clotting process?
-Presence of platelets produces by bone marrow
-Von Willebred factor which is generated by the vessle endothelium
-Vitamin K as a clotting factor. Vitamin K is synthesized in liver. If liver isn’t working you won’t have enough vitamin K and will lead you to liver disorder
What is clot retraction and dissolution?
-Other significant factors that happen with homeostasis
-Process that involves interaction of various factors so that clots can get smaller or dissolve
-It is an attempt to reduce the risk of thrombus formation
What are intrinsic and extrinsic coagulation pathways?
-Both end up in the same reaction which is clotting of the blood
Factors required for coagulation to happen
-Calcium factors x &V, and platelets phospholipids will combine to form prothrombin activator
-The prothrombin activator turns into prothrombin then intro thrombin
-This interaction cause the conversion of fibrinogen into fibrin create a insoluble blood clot
What is the regulation of blood coagulation?
-Regulated by Antithrombin lll. Inactivates coagulation factors and neutralizes thrombin
-Regulate by Protein C, acts as a anticoagulant by inactivating factors V and Vll
Check and balance so the blood doesn’t over clot or underclot. Alot of clot formation can cause occusion in vessels cause ischemia and underclotting could cause excessive bleeding
***Regulation of bLood coagulation
What are other factors responsible for blood coagulation?
-Protein S, accelerates the action of protein
-Plasmin breaks down fibrin into fibrin degradation products and act as anticoagulants
What are Conditions that create increased platelet function/ hyper coagulability:
-Atherosclerosis
-Diabetes mellitus
-Smoking
-Elevated blood lipod and cholesterol levels
-Increase platelet activity
What are conditions that cause accelerated activity of the coagulation system?
-Pregnancy, and the puerperium
-Use of oral contraceptives
-Post surgical state
-Immobility
-Congestive heart failure
-Malignant disease
***Hyper coagulability states
What does hyper coagulability put you at risk for?
Increase risk of clot or thrombus formation in the arterial or venous circulations
***Hyper coagulability states
What happens in the arterial system at with hypercoagulability
Arterial system at risk is associated with the tuburlance that whirls blood around with force of arterial pressure which leed to platlet adherance