The differential propagation of transverse and longitudinal polarizations is important in seismology. Each phonon mode can be split into one longitudinal and two transverse polarization branches. The corpus cavernosum contains connective fibers arranged both parallel and perpendicular to the longitudinal axis. They are categorized as longitudinal and transverse arches. Transverse tears are more common than longitudinal or complex ones. Length can be adjusted by longitudinal muscle fibers parallel to the longitudinal axis. Wind waves are thus a combination of transversal and longitudinal waves. This organizes the bed into two cylindrical masses contrarotating on parallel longitudinal axes. This can be controlled using the annular and longitudinal muscles. In order to maintain strength and durability it employs both longitudinal and latitudinal reinforcing ribs. Between the circular and longitudinal muscle layers is the myenteric plexus. Contraction of longitudinal muscles can shorten the cylinder. The associated waves are called "longitudinal" and "shear" elastic waves. Cross-sectional data shows typically an earlier onset of cognitive decline in comparison with longitudinal data. Underneath the epidermis lies a layer of longitudinal muscle cells.