Regulation of Arteriolar Resistance

Question 1

Explain the origin of Korotkoff sounds and their use

Answer 1

Arterial pressure can be measured by Korotkoff sounds.

Question 2

Explain the mechanism that prevents blood clotting in vessels

Answer 2

• Stops blood contacting collagen: no platelet aggregation
• Produces prostacyclin and NO: inhibit platelet aggregation
• Produces tissue factor pathway inhibitor (TFPI): stops thrombin production
• Expresses thrombomodulin and heparin: binds to thrombin and inactivates it
• Secretes tissue plasminogen activator (t-PA): turns plasminogen into plasmin and digests thee clot

Question 3

What two mechanisms are involved in clotting?

Answer 3

• The formation of a platelet plug

- Formation of a fibrin clot