The phenomenon describing decreased pressure at a stenotic site due to increased velocity within the stenosis is described by which effect, and is based on maintaining energy along the vessel?

The phenomenon describing decreased pressure at a stenotic site due to increased velocity within the stenosis is described by which effect, and is based on maintaining energy along the vessel?

• A. Bernoulli effect
• B. Energy balance
• C. Continuity
• D. Viscosity

Answer: (A)

Bernoulli's principle explains this. In steady, incompressible flow along a streamline, the sum of static pressure and kinetic energy per unit volume remains constant. When a vessel narrows (stenosis), the cross-sectional area decreases, so to keep the same volume flow rate, velocity must increase in the narrowed region (this is the continuity idea). As velocity rises, the static pressure must drop to keep the total energy the same. That lowered pressure at the stenosis is the phenomenon described by Bernoulli's principle, reflecting energy conservation along the vessel. Viscosity would introduce energy losses and isn’t the direct cause of this pressure–velocity relationship. Continuity explains why velocity goes up in the narrow segment, but the associated pressure drop is specifically accounted for by Bernoulli's principle, which ties velocity changes to pressure changes along a streamline.

Bernoulli's principle explains this. In steady, incompressible flow along a streamline, the sum of static pressure and kinetic energy per unit volume remains constant. When a vessel narrows (stenosis), the cross-sectional area decreases, so to keep the same volume flow rate, velocity must increase in the narrowed region (this is the continuity idea). As velocity rises, the static pressure must drop to keep the total energy the same. That lowered pressure at the stenosis is the phenomenon described by Bernoulli's principle, reflecting energy conservation along the vessel.

Viscosity would introduce energy losses and isn’t the direct cause of this pressure–velocity relationship. Continuity explains why velocity goes up in the narrow segment, but the associated pressure drop is specifically accounted for by Bernoulli's principle, which ties velocity changes to pressure changes along a streamline.