Flashcards in haemostasis, hemorrage and shock Deck (47)
what effect does a decrease in blood vol have on BP and delivery of nutrients to cells?
decreased BP and delivery
what causes shock?
lack of blood flow to tissues
what are the effects of shock?
decreased BP and delivery of nutrient to cells
what are the 4 physiological responses to blood loss?
immediate - stop bleeding
short term - restore BP
medium term - restore fluid vol
long term - replace blood constituents
the immediate response to shock is to stop blood flow, what is this called?
what responses are involved in hemostasis?
- vascular response
- platelet response
- plasma response (coagulation)
what role does smooth muscle play in the vascular response go hemostasis?
vascular spasms - vasoconstriction
what role does endothelium play in the vascular response go hemostasis?
- platelet adhesion and aggregation
- anticlotting and fibrinolysis
describe the platelet response in Hemostasis
- damage to BV causes turbulent blood flow, platelets come into contact with collagen vessel wall
- platelets clump together (aggregation) forming platelet plug
during hemostatic coagulation, plasma proteins and tissue components combine to convert what into what?
fibrinogen into fibrin
which fibrous molecule forms a blood clot?
where are the majority of clotting factors made?
synthesis of several clotting factors requires which vitamin?
describe the enzyme cascade that results in the production of insoluble fibrin
- prothrombin is converted to thrombin in the presence of factor Xa, Ca, factor V and phospholipid
- prothrombin converts fibrinogen to soluble fibrin
- soluble fibrin is converted to insoluble fibrin by factor XIIIa
what is bloodclotting factor I?
what is bloodclotting factor II?
what is bloodclotting factor III?
tissue factor (thromboplastin)
what is bloodclotting factor IV?
how many bloodclotting factors are there?
both the extrinsic and extrinsic coagulation pathways work on factor X to form what?
what activates the intrinsic coagulation pathway?
- vascular damage
what activates the extrinsic coagulation pathway?
- tissue damage
what factors does the intrinsic coagulation pathway involve ?
factors VIII, IX, XI, XII
what factor does the extrinsic coagulation pathway involve ?
both coagulation pathways work in the presence of what?
calcium and phospholipid
which coagulation pathway is more important in initiated the clot after injury ?
which coagulation pathway is more important at maintaining the blood clot once it has started ?
which coagulation pathway has a role in thrombosis?
after the blood clot has served its function it dissolves, what is this known as?