Blood - Hemostasis

Question 1

What are the three stages to stop bleeding?

Answer 1

1. Vascular spasms
2. Platelet plug formation
3. Coagulation (blood clotting)

(Think 3 little pigs house)

Question 2

What occurs during Vascular spasms?

Answer 2

Smooth muscle contracts (the blood vessel), causing vasoconstriction to reduce blood loss

Question 3

How does platelet plug formation work?

Answer 3

Injury to the lining of a blood vessel will expose collagen fibres, there for platelets will stick. Those platelets will then release chemicals that make nearby platelets sticky, forming the plug

Question 4

What occurs during coagulation?

Answer 4

Thrombin and fibrinogen proteins join to create fibrin

Fibrin then acts as a mesh and traps RBCs and platelets, forming a clot

Question 5

Where is thrombin and fibrinogen produced? Where are they after they’re released?

Answer 5

Thrombin is generated from prothrombin (produced by liver using vitamin K). Fibrinogen is produced by liver as well.

Prothrombin and fibrinogen circulate bloodstream in its inactive form until needed