Haemostasis

Question 1

What is endothelium and what are its functions

Answer 1

A layer of cells lining inner surface of all vessel walls and it controls blood fluidity and flow.

Question 2

What is haemostasis

Answer 2

A process that causes bleeding to stop.

Question 3

What 3 things do platelets do in haemostasis

Answer 3

platelet adhesion, activation, and aggregation.

Question 4

What is thrombocytopenia

Answer 4

Low platelet count in the blood

Question 5

Outline how platelets cover a wound

Answer 5

adhesion- to exposed collagen

activation: serotonin, exocytose dense granules
aggregation: stimulated by ADP, blocked by prasugrel.

Question 6

Where are clotting factors made

Answer 6

They are made in the liver and Vit K is required to synthesize enzyme coagulation factors.

Question 7

What is protein C

Answer 7

It is a coagulation inhibitor, starts as an inactive enzyme made by the liver, and is activated on surface of endothelial cells.

Question 8

What does Vit K deficiency lead to

Answer 8

Results in clotting insufficiency, caused by GI disease or no fat absorption. Warfarin prevents the recycling of Vit K.

Question 9

What are anti-platelet agents

Answer 9

Prevents clotting in arteries,

aspirin (COX inhibitor)- blocks the formation of thromboxane A2 in platelets.

Question 10

What are fibrinolytic

Answer 10

They are clot busters e.g. streptokinase or urokinase.