Question

Hemostasis is the first stage of wound healing.

1. In which blood vessel classifications are vascular spasms observed?
2. How are the intrinsic and extrinsic pathways activated differently?
3. How would liver failure affect these pathways?

Answer 1

Part a

The arteries and arterioles are the ones that will constrict in the process .During hemostasis, a brief spasm of vasoconstriction occurs, which slows blood flow into the injured area while the clot forms. Vasoconstriction during hemostasis: Blood vessel experiencing vasoconstriction as its smooth muscle contracts while the blood clot forms.

Part b

Intrinsic

The intrinsic pathway is activated by trauma inside the vascular system, and is activated by platelets, exposed endothelium, chemicals, or collagen. This pathway is slower than the extrinsic pathway, but more important. It involves factors XII, XI, IX, VIII.

Extrinsic

The extrinsic pathway is activated by external trauma that causes blood to escape from the vascular system. This pathway is quicker than the intrinsic pathway. It involves factor VII.

Part c

As the liver has the ability for synthesis of cloting factors like the intrinsic and extrinsic factors . Also the activation of pathway will not take place leading to slow coagulation