Pressure Change in an Arterial Constriction

摘要

Consider the following ConcepTest.1 A platelet is drifting with the blood flowing through a horizontal artery. As the platelet enters a constriction, does the blood pressure increase, decrease, or stay the same? Figure 1 sketches the situation. The blood is assumed to be incompressible and to have the density p = 1000 kg/m3 of water. Also, for simplicity the pressure p is taken to be uniform across any constant- diameter region of the artery, by neglecting boundary layer drag at the surfaces of the artery, and the flow is assumed to be laminar and inviscid.