Fig. 1.

(a) Porcine aortic arch. Black dotted lines demarcate ascending aortic ring. White star symbolizes a marker used to keep track of tissue sample orientation. (b) Ascending aortic ring with intima, adventitia, adipose, and loose connective tissue removed. Axial and circumferential directions shown with white arrows. (c) Undeformed, typical uniaxial sample in CIRC orientation with speckling prior to loading. Arrow indicates orientation and direction of pull. (d) Undeformed, typical biaxial sample with speckling prior to loading. Arrows indicate orientation and direction of pull.