Intro to Coagulation and Primary Hemostasis (Exam 2)

Hemostasis is the ______ of bleeding.

arrest

Coagulation is the formation of a ______.

thrombus (clot)

In normal hemostasis, there is a balanced level of ______ molecules and ______ molecules.

procoagulant, anticoagulant

When injury or trauma occurs, there is an imbalance in favor of ______ and inhibition of ______.

coagulation, anticoagulants

This causes ______ formation and breakdown.

thrombus/clot

______ is clot breakdown.

FInbinolysis

The fibrinolytic system is activated within ______ of clot formation.

hours

What are the two parts of thrombus formation?

Primary and secondary hemostasis

______ triggers primary hemostasis to begin.

Injury

During primary hemostasis, endothelial cells in the vascular intima ______ to seal the wound.

contract

In addition, ______ aggregate to form a plug.

platelets

Primary hemostasis is a ______ response that results in the formation of a platelet plug.

rapid, short-lived

______ triggers secondary hemostasis to begin.

Primary hemostasis

Secondary hemostasis is needed for ______ and ______.

larger wounds, major bleeding

During secondary hemostasis, interaction of protein enzymes and/or cofactors forms an insoluble ______ beneath the platelet plug.

fibrin mesh

The fibrin mesh is formed by the activation cascade of the ______.

coagulation factors

The combination of primary and secondary hemostasis leads to the end product formation known as a ______.

thrombus/clot

Secondary hemostasis is a ______ response.

delayed, long term

What functions is the vascular system capable of carrying out'?

- Procoagulant

- Anticoagulant

- Fibrinolytic

Coagulation factors interact with the ______ of the blood vessel to form clots.

tunica intima (innermost layer)

Normal endothelial cells are ______.

non thrombogenic/antithrombotic

Normal endothelial cells secrete ______ and ______ to inhibit platelet function.

nitric oxide, prostacyclin (PGI2)

Normal endothelial cells inhibit coagulation via ______.

thrombomodulin (tissue factor pathway inhibitor)

Normal endothelial cells activate fibrinolysis via ______.

tissue plasminogen activator (tPA)

Damaged endothelial cells become thrombogenic by secreting ______, which helps platelet function.

von Willebrand factor (vWF)

Damaged endothelial cells expose ______, which activates platelets.

collagen

Damaged endothelial cells also release ______ which inhibits fibrinolysis.

plasminogen activator inhibitor (PAI-1)

Normal platelet count

150,000-450,000 PLTs/uL

How do platelets contribute to forming the platelet plug of primary hemostasis?

Platelet activation, aggregation, secretion

Thrombocyte (PLT) maturation is also known as ______.

megakaryopoiesis

Megakaryopoiesis occurs through _______.

endomitosis (mitosis without telophase)

What are the stages of megakaryocytic maturation?

1. Megakaryoblast

2. Promegakaryocyte

3. Mature megakaryocyte

4. Platelet

What seven transmembrane repeat receptors (STRs) are responsible for platelet activation?

- PAR1 and PAR4

- P2Y1 and P2Y12

- TPα and TPβ

- α2A

PAR1 and PAR4 react with ______.

thrombin

P2Y1 and P2Y12 react with ______.

ADP

TPα and TPβ react with ______.

TXA2

α2A reacts with ______.

epinephrine

What membrane glycoproteins are responsible for platelet adhesion/aggregation?

- GP Ia/IIa ad GP VI

- GP Ib/IX/V

- GP IIb/IIIa

- GP IV

GP Ia/IIa ad GP VI adhere to ______.

collagen

GP Ib/IX/V adheres to what three things?

Collagen, thrombin, and vWF

GP IIb/IIIa adhere to ______ and ______.

fibrinogen, vWF

GP IV adheres to ______.

thrombospondin receptor

What do dense bodies contain?

ATP, ADP, epinephrine and calcium

What do alpha granules contain?

- PLT-derived growth factor

- Heparin neutralizing factor

- Plasminogen activator inhibitor

- Albumin

- Fibrinogen

- P-selectin

- Calcium

- Factor V

Lysosomal granules contain hydrolytic enzymes that enhance activation of the ______ clotting cascade.

intrinsic

The dense tubular system is derived from the smooth ER of ______.

immature megakaryocytes

The dense tubular system is responsible for the production of ______ and ______.

thromboxane A2, prostacyclin

The dense tubular system is also responsible for the sequestration of ______.

calcium

The open canalicular system (SCCS) consists of open canals that are responsible for bringing the granules to the surface for ______ activation.

platelet

During platelet adhesion to collagen, ______ binds to ______.

GP Ib/IX, vWF

Next, platelet aggregation occurs (PLT to PLT), where expression of ______ binds to ______.

GP IIb/IIIa, fibrinogen

The activated platelets will then secrete the substances present in their granules to activate ______.

secondary hemostasis (coagulation cascade)

What are the platelet agonists, which activate platelets when bound to platelet receptors?

- ADP

- Thromboxane A2

- Thrombin

- Epinephrine

- Arachidonic acid

These platelet agonists initiate platelet ______.

aggregation

A white clot is made up of ______ and ______.

platelets, vWF

White clots are formed in ______ hemostasis.

primary

Red clots are made up of ______ and ______.

fibrin, RBCs

Red clots are formed in ______ hemostasis.

secondary

Red clots are essential for ______.

wound repair

Red clots are a sign of inappropriate coagulation in ______ and ______.

DVT, PE