Mineralized tissue of shark vertebral centra studied with microCT under in situ load

Shark vertebral bodies (centra) possess remarkable resistance to millions of cycles of large in vivo strains exceeding 4 to 8%. These strains are enormous for a mineralized tissue, and it appears that the centra evolved to achieve this performance through a hierarchy of structures spanning dimensions from centimeters to nanometers. At the 1μm scale, blocks cut from centra and imaged with synchrotron microCT demonstrate that the centra tissue consists of closely spaced, mineralized trabeculae. An outstanding question is: How do these trabeculae deform to accommodate these large strains. This paper presents recently obtained synchrotron microCT results on in situ loading of blocks of shark centra and examines the deformation modes of the interconnected array of trabeculae.