Physiology LE 2: Hemostasis

What is the first step for hemostasis to occur?

Injury to the vessel wall

What is hemostasis described as?

The prevention of blood loss

What is the primary function of thromboxane A2 in hemostasis?

Vasoconstriction

What is the first step in primary hemostasis?

Vascular constriction Signup and view all the answers

What is the result of the smooth muscle in the vessel wall contracting near the injury point?

Decreased blood loss Signup and view all the answers

What is the primary mechanism of platelet plug formation?

Adhesion, Activation, and Aggregation Signup and view all the answers

What is the main difference between primary and secondary hemostasis?

Primary hemostasis involves vascular spasm and platelet plug formation, secondary hemostasis involves the coagulation cascade Signup and view all the answers

What is the final step in the mechanism of hemostasis?

Growth of fibrous tissue Signup and view all the answers

What is the role of fibrin in coagulation?

Forms a mesh that traps more platelets and erythrocytes Signup and view all the answers

What is the term for the ratio of the patient's prothrombin time to a normal prothrombin time?

International Normalized Ratio (INR) Signup and view all the answers

What is the purpose of the prothrombin activator in coagulation?

Converts prothrombin into thrombin Signup and view all the answers

What are the two types of pathways involved in coagulation?

Extrinsic and Intrinsic pathways Signup and view all the answers

What is the term for the protein that plays a major role in platelet adhesion and blood clotting?

von Willebrand factor (vWF) Signup and view all the answers

What is the result of the platelet plug formation?

Formation of a clot Signup and view all the answers

What is the term for the ion that plays a crucial role in the blood clotting process?

Calcium ion Signup and view all the answers

What is the term for the process by which the body stops bleeding after an injury?

Hemostasis Signup and view all the answers

What is the role of ADP in platelet activation?

It binds to P2Y12 receptors to activate more platelets Signup and view all the answers

What is the role of thrombin in the coagulation process?

Formation of fibrin fibers Signup and view all the answers

Which platelet receptor is endowed with the capacity to bind fibrinogen after a conformational change?

GP IIb/IIIa Signup and view all the answers

What is the role of glycocalyx in preventing blood clotting?

Preventing platelet adhesion Signup and view all the answers

What is the result of local myogenic spasm in blood vessels?

Reduced blood flow Signup and view all the answers

What is the role of thrombin in the clotting process?

It converts fibrinogen to fibrin, stabilizing the platelet plug Signup and view all the answers

What is the origin of platelets in the body?

Bone marrow from megakaryocytes Signup and view all the answers

What is the function of prostacyclin in the body?

Inhibiting platelet aggregation Signup and view all the answers

What binds to GPIb/Ia to activate more platelets and form bridges?

vWF Signup and view all the answers

What is the role of antithrombin III in the coagulation cascade?

Inhibiting thrombin and Factor Xa Signup and view all the answers

What is the normal range of platelet count in blood?

150,000 to 300,000 units per μL Signup and view all the answers

What is the result of platelet activation on GPIIb/IIIa?

It endows GPIIb/IIIa with the capacity to bind fibrinogen Signup and view all the answers

What is the role of serotonin in platelet activation?

It activates more platelets Signup and view all the answers

What is the function of alpha granules and dense tubules in platelets?

Release of local contractile proteins Signup and view all the answers

What is the purpose of the common pathway in the coagulation cascade?

Forming the prothrombin activator Signup and view all the answers

What is the function of thrombomodulin in the coagulation cascade?

Forming a complex with thrombin Signup and view all the answers

What is the role of fibrinogen in the formation of a platelet plug?

It forms bridges between platelets Signup and view all the answers

What is the purpose of glycoprotein on the platelet cell membrane surface?

To prevent adherence to normal endothelium Signup and view all the answers

What is the role of protein C in the coagulation cascade?

Acting as an anticoagulant Signup and view all the answers

What is the result of the binding of vWF to GPIb/Ia?

It activates more platelets and forms molecular bridges Signup and view all the answers

What is the state of blood in the physiologic state?

Constantly anticoagulated Signup and view all the answers

What is the role of thromboxane A2 in platelets?

Vascular spasm or vascular wall contraction Signup and view all the answers

What is the function of heparin in the coagulation cascade?