Which type of blood flow is often observed distal to the area of maximum stenosis?

• A. Laminar flow
• B. Turbulent flow
• C. Parabolic flow
• D. Reversed flow

Answer: (B)

Stenosis creates a high-velocity jet as the blood is forced through the narrowed segment. When this jet exits into the downstream vessel, it disrupts the smooth layering of blood cells and flow separates from the wall, forming swirls and eddies. This combination of high speed and flow separation increases chaotic motions and raises the Reynolds number, leading to turbulence. In practice, you often see post-stenotic turbulent flow distal to a significant narrowing, whereas smooth laminar or parabolic flow would be expected in an unobstructed vessel, and reversed flow is not the typical pattern seen right after the maximum stenosis. So turbulence best describes what’s observed downstream.