Fig. 2. Artery configuration for circumferential overstretch.

Light microscope image of a single arterial ring from a sheep MCA just prior to (left) and at peak (right) overstretch. These rings, or short lengths of otherwise intact artery, came from longer MCA segments that were first mounted and preconditioned similar to segments loaded axially (Fig. 1). However, following preconditioning, segments were chopped into short lengths so that the two 28 gauge hypodermic needles shown could be passed through the lumen. Small black dots are microspheres used to track local strain. Axes and scale bar (0.5 mm) apply to both images.