Coagulation 1 - Hemostasis

liquid, thrombus, blood flow

Hemostasis

• Cellular and biochemical events that collaborate to:

  • Keep blood ______ within the vein and arteries

  • Prevent hemorrhage by forming a ________

  • Re-establish _____ ____ during the healing process

Vascular, coagulation, fibrinolytic

Hemostasis Maintenance

• _______ system

• Platelets

• Plasma _________ factors

• _____________ system

constriction, von Willebrand, platelets

Vascular System

• Vaso__________

• Endothelial cells release ___ __________ factor during vascular injury and activate ________

inactivated, constriction, platelet plug, coagulation cascade, fibrinolysis

Platelets

• Platelets normally circulate freely in plasma, in an __________ state

  • Help induce vaso_________ (vasospasm)

  • Form a ________ _____ to stop further bleeding

  • Activate the ___________ ________ to stabilize the platelet plug

  • Initiate repair processes including clot retraction and clot dissolution (____________)

adhesion, activation, degranulation, aggregation, activation, fibrin

Platelets in Action

• Damage to blood a vessel initiates platelet activation:

  • ________ of platelets to the damaged vascular wall

  • _________ leading to platelet ___________, which stimulates changes in platelet shape and biochemistry

  • ___________ as platelet-vascular wall and platelet-platelet adherence increases

  • ________ of the clotting system and development of an immobilizing meshwork of platelets and ______

endothelial, thromboxane, prostacyclin, calcium

1. Subendothelial Exposure

   • Platelets rush to close the __________ opening after injury

   • Occurs after endothelial sloughing

   • Platelets begin to fill endothelial gaps

   • Promoted by ___________ A₂ (TXA₂)

   • Inhibited by ____________ I₂ (PGI₂)

   • Platelet function depends on many factors, especially ________

GP1b, endothelial, collagen, vWF, receptors, glycoproteins

2. Adhesion

   • Platelets Glycoprotein 1b (____) attaches to vWF (subendothelial matrix)

   • Adhesion is initiated by loss of ____________ cells, which exposes adhesive glycoproteins such as _______ and ___ in the subendothelium

   • vWF and other adhesive glycoproteins in the plasma deposit to the damage area

   • Platelets adhere to the subendothelium through ________ that bind to adhesive ______________ (GPIb, GPIa/IIa, GPIIb/IIIa)

stickiness, TXA2, constriction, degranulation, IIb/IIIa, shape

3. Activation

   • Platelet shape change and increase __________

   • Platelets initiate production of thromboxane A2 (____)

     • Vaso__________

     • ____________ (ADP recruits and activated other platelets)

     • Aggregation

   • After platelets adhere they undergo an activation process that leads to a confirmational change in GP___/____ receptors, resulting in their ability to bind adhesive proteins, including fibrinogen and vWF

   • Changes in platelet _____

   • Formation of pseudopods

   • Activation of arachidonic pathway

COX-1, aspirin, decreased, decreased

• Cyclooxygenase (___-_) converts arachidonic acid to TXA₂ in platelets

• _______ irreversibly inactivates COX-1

  • _______ production of TXA₂

  • _______ platelet activation and aggregation

TXA₂, GPIIb/IIIa, blood clot, coagulation

4. Aggregation

   • Induced by release of ____

   • Adhesive glycoproteins bind simultaneously to ______/____ on two different platelets (platelet-platelet binding)

   • Stabilization of the platelet plug (____ ____) occurs by activation of __________ factors, thrombin, and fibrin

RBCs, platelets, fibrin

5. Platelet plug formation

   • ____ and _________ enmeshed in ______

   • The actual bandaid

platelets, thrombin, plasminogen

6. Clot retraction and clot dissolution

   • Clot retraction, using large number of ________, joins the edges of the injured vessels

   • Clot dissolution is regulated by _______ and __________ activators

   • Fibronolytic system

Coagulation Cascade

What do platelets activate?

aPTT (activated partial thromboplastin time)

a blood test that measures how long it takes for your blood to clot. It's used to evaluate the intrinsic and common pathways of the coagulation cascade, helping assess the function of various clotting factors

PT (prothrombin time)

measures how long it takes blood to clot, specifically focusing on the extrinsic and common pathways of the blood clotting cascade. It's used to assess blood clotting ability, monitor the effects of blood thinners like warfarin, and check for potential bleeding disorders or liver problems. 

Primary Hemostasis

What does this picture depict?

Secondary Hemostasis

What does this picture depict?

vascular, platelets, platelet plug, temporarily

Hemostasis Stages: Primary Hemostasis

• Dependent on ________ intima and _________

• Formation of “primary ________ ____”

• ____________ stops bleeding

coagulation, fibrinolysis, thrombin, platelet plug

Hemostasis Stages: Secondary Hemostasis

• Dependent on __________ and ____________

• Coagulation cascade creates ________ (→ fibrin) that “strengthens the ________ ____”

petechiae, purpura, epistaxis, hematemesis, telangiectasia, mucosal

Symptoms of a Primary Hemostasis Problem

• ________ (pinpoint)

• _______ - purple discoloration of skin

• __________ - nose bleed

• ___________

• Menorrhagia

• _____________ - spider-like vessels

• _______ bleeding

ecchymosis, hemarthrosis, delayed, oozing

Symptoms of a Secondary Hemostasis Problem

• __________ - deep tissue bleed

• ___________ - joint bleed

• ________ bleeding and ______ from wounds

Platelet tests

What kind of tests do you run if you think its a problem with primary hemostasis?

platelet count, time, function, aggregation

Primary Hemostasis: Platelet tests

• CBC ______ _____/slide

• Platelet function tests:

  • Bleeding ____

  • Platelet _______ analyzer (PF 100 or PFA)

  • Platelet __________

Coagulation Tests

What kind of tests do you run if you think its a problem with secondary hemostasis?

prothrombin, thromboplastin

Secondary Hemostasis: Coagulation Tests

• __________ time (PT/INR)

• Activated Partial ____________ time (aPTT)