Hemostasis

Question 1

Hemostasis (from Greek_____ = blood,_____ = stopping)

Answer 1

haima

stasis

Question 2

explain hemostasis

Answer 2

the physiological process by which the body maintains blood in a fluid state under normal conditions and forms a clot to stop bleeding when a blood vessel is injured.

Question 3

The systems composing the process of hemostasis are the (4)

BPCF

Answer 3

blood vessels
platelets
coagulation factors
fibrinolysis components

Question 4

4 Stages of Hemostasis

Answer 4

1. Vasoconstriction
2. Primary Hemostasis
3. Secondary Hemostasis (Coagulation Cascade)
4. Fibrinolysis (Clot Dissolution)

Question 5

• Vascular Spasm
• Immediate narrowing of the blood vessel to reduce blood loss.

Answer 5

VASOCONSTRICTION

Question 6

VASOCONSTRICTION

Answer 6

• Vascular Spasm
• Immediate narrowing of the blood vessel to reduce blood loss.

Question 7

• Platelet adhesion, activation, and aggregation form a temporary platelet plug.
• Rapid, short-lived response

Answer 7

PRIMARY HEMOSTASIS

Question 8

PRIMARY HEMOSTASIS

Answer 8

• Platelet adhesion
• activation
• aggregation
• form a temporary platelet plug

• Rapid, short-lived response

Question 9

• Coagulation cascade

Answer 9

SECONDARY HEMOSTASIS

Question 10

• Triggered by external trauma to the vessel (like a cut)

Answer 10

• Extrinsic Pathway

Question 10

• Triggered by damage inside the blood vessel (like exposure of collagen)

Answer 10

Intrinsic Pathway

Question 11

Intrinsic Pathway vs Extrinsic Pathway

Answer 11

• Triggered by damage inside the blood vessel (like exposure of collagen)

• Triggered by external trauma to the vessel (like a cut)

Question 12

Intrinsic and Extrinsic pathway

Nota bene: Both pathways converge at the_______, leading to _____formation.

Answer 12

Common Pathway

fibrin clot

Question 13

• Triggered by damage inside the blood vessel (like exposure of collagen)
• Involves clotting factors XII, XI, IX, and VIII.

Answer 13

Intrinsic Pathway

Question 14

Intrinsic Pathway

Clotting Factors involved

Answer 14

XII, XI, IX, VIII

Question 15

• Triggered by external trauma to the vessel (like a cut)
• Involves Tissue Factor (Factor
Ill) and Factor VII.

Answer 15

Extrinsic Pathway

Question 16

Extrinsic Pathway

• Involves what coagulation factors?

Answer 16

Tissue Factor (Factor
Ill)

Factor VII

Question 17

The common pathway

begins when _____is activated to_____ by either the intrinsic or extrinsic pathway.

Answer 17

Factor X

Factor Xa

Question 18

• Factor Xa, along with cofactor Va and calcium ions (Ca^2+), forms the________.

Answer 18

prothrombinase complex

Question 19

prothrombinase complex

Involves what factors???

Answer 19

FXa
FVa
Calcium

Question 20

• This complex converts prothrombin (Factor Il) into thrombin (Factor lIa).

Answer 20

Prothrombinase complex

Question 21

Prothrombinase complex converts what?

Answer 21

prothrombin (Factor Il) into thrombin (Factor lIa)

Question 22

After the formation of prothrombinase complex and activation of prothrombin (FII) to thrombin (FIIa)

• Thrombin then:

Answer 22

• Converts fibrinogen (Factor I) into fibrin, forming the basic framework of the clot

• Activates Factor XIII, which cross-links fibrin strands, thereby stabilizing the clot

Question 23

prothrombinase complex

• This complex converts prothrombin (Factor Il) into thrombin (Factor lIa).

• Thrombin then:

• Converts_____ into____, forming the basic framework of the clot

• Activates____, which cross-links fibrin strands, thereby stabilizing the clot

Answer 23

fibrinogen (Factor I) -> fibrin

Factor XIII

Question 24

What factor stabilizes the clot?

Answer 24

Factor XIII

Question 25

______ is released from activated platelets and is crucial for blood clot formation. When platelets aggregate, they express it on their surface, providing a site for coagulation factors to bind and initiate the coagulation cascade

Answer 25

Platelet factor 3 (PF3), also known as phosphatidylserine

Question 26

Phase 1

Answer 26

Intrinsic and Extrinsic Pathway

Question 27

The IXa/VIIa complex is also known as the _______ complex crucial for activating Factor X in the coagulation cascade

Answer 27

intrinsic tenase complex

Question 28

What initiates intrinsic pathway

Answer 28

Exposure to collagen

Question 29

_______, is a crucial protein that initiates the extrinsic pathway (blood clotting.)

Answer 29

Tissue thromboplastin factor, also known as tissue factor or coagulation factor III

Question 30

injury to a blood vessel, exposing tissue factor (TF) to the bloodstream. TF then binds with Factor VIIa to form the_______. This complex activates Factor X to Xa and Factor IX to IXa. These activated factors, along with Factor Va on the surface of activated platelets, generate small amounts of thrombin.

Answer 30

extrinsic tenase complex

Question 31

The small amount of thrombin produced in the initiation phase plays a vital role in amplifying the coagulation cascade. Thrombin activates platelets and several coagulation factors, including Factors V, VIII, and XI. Activated Factor VIIIa binds to Factor IXa, forming the ______ on the platelet surface. This complex is significantly more efficient at activating Factor X to Xa than the extrinsic tenase complex, leading to a rapid increase in Factor Xa production.

Answer 31

intrinsic tenase complex

Question 32

Phase 3: Propagation In this final phase, the large amounts of Factor Xa generated by both the intrinsic and extrinsic pathways combine with Factor Va on the platelet surface to form the_________. This complex efficiently converts______ to ______. Thrombin then cleaves _______ to ______ monomers. These fibrin monomers spontaneously polymerize to form a loose fibrin mesh. Finally, Factor______, activated by_____, cross-links the fibrin strands, creating a stable and strong fibrin clot that reinforces the initial platelet plug and effectively stops the bleeding.

Answer 32

prothrombinase complex prothrombin (Factor II) to large amounts of thrombin fibrinogen (Factor I) into fibrin FXIIIa activated by thrombin

Question 33

• Clot dissolution • Growth of fibrous tissue into the blood clot to close the hole in the vessel permanently. • Plasminogen is activated to become plasmin which is responsible in dissolving the clot.

Answer 33

FIBRINOLYSIS

Question 34

Plasminogen is converted into plasmin by______ or _____

Answer 34

tissue-type plasminogen activator (tPA) urokinase plasminogen activator (uPA)

Question 35

______is a serine protease, an enzyme that breaks down proteins. Its primary target is______, the main structural component of the blood clot. Plasmin cleaves the fibrin meshwork at various points, leading to the formation of soluble fragments called________. These FDPs are then cleared from the circulation by the liver and kidneys.

Answer 35

plasmin fibrin fibrin degradation products (FDPs)

Question 36

Explain fibrinolysis and why it is important

Answer 36

Fibrinolysis is the process of breaking down fibrin clots after tissue healing. It’s important because it prevents blood clots from growing too large and blocking blood vessels, ensuring normal blood flow.