Which description corresponds to early systolic laminar flow?

Which description corresponds to early systolic laminar flow?

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

Answer: (D)

Velocity profiles in laminar arterial flow can be flat or peaked depending on the conditions. In early systole, the blood is ejected rapidly from the heart, and the entire cross-section is set into motion with about the same speed before viscous forces near the walls have time to develop a velocity gradient. This creates a nearly uniform velocity across the vessel radius—a plug-like flow. As systole continues, the boundary layer develops and the profile can become more parabolic, with faster center flow and slower near the walls. Turbulence would disrupt laminar flow entirely, which isn’t characteristic of normal early systolic flow. So the description that matches early systolic laminar flow is plug flow.

Velocity profiles in laminar arterial flow can be flat or peaked depending on the conditions. In early systole, the blood is ejected rapidly from the heart, and the entire cross-section is set into motion with about the same speed before viscous forces near the walls have time to develop a velocity gradient. This creates a nearly uniform velocity across the vessel radius—a plug-like flow. As systole continues, the boundary layer develops and the profile can become more parabolic, with faster center flow and slower near the walls. Turbulence would disrupt laminar flow entirely, which isn’t characteristic of normal early systolic flow. So the description that matches early systolic laminar flow is plug flow.