Haemostasis

Question 1

What is Haemostasis

Answer 1

Complex sequence of physical and biochemical changes induced by damage to tissues and blood vessels, which transform the blood into a clot and later bring about the repair of damaged vascular endothelium.

Question 2

What is Vascular Response?

Answer 2

Vasoconstriction which reduces bleeding allowing time for clotting factors to be initiated
(Blood Vessels, Endothelium, Endothelin)

Question 3

What are the 4 steps of the Primary Haemostatic Plug?

Answer 3

Platelet Adhesion
Platelet Activation
Platelet Secretion
Platelet Aggregation

Question 4

What happens in Platelet Adhesion?

Answer 4

Platelets stick together at the site of damage to endothelium

Question 5

What happens in Platelet Activation?

Answer 5

Platelets become activated when exposed to collagen from an injured blood vessel

Question 6

What happens in Platelet Secretion?

Answer 6

Chemicals are released that further increase the aggregation

Question 7

What happens in Platelet Aggregation?

Answer 7

The platelets aggregate (stick together) to form clumps

Question 8

What does the Secondary Haemostatic Plug involve?

Answer 8

Plama Proteins, Platelets, Coagulation Factors, Anticoagulation Factors
Plasma Proteins circulate in an inactive form in the blood and are stimulated by two pathways

Question 9

What is are the two pathways?

Answer 9

Intrinsic - Activated by collagen exposure from endothelial injury when the blood vessel is damaged
Extrinsic - Initiated due to tissue factors released extravascularly from injured tissues

Question 10

What is the purpose of the Total Lysis of the Clot?

Answer 10

To maintain blood in its fluid form, the clot needs to be broken down

Question 11

What breaks down a clot?

Answer 11

Plasminogen Activator activates Plasminogen to turn into Plasmin, which breaks down the clot