[Collagen fiber orientation in the tunica media of the aorta as a function of intraluminal pressure].

X-ray diffraction investigation and hystological analysis have been carried out on segments of pig's aortic media layer under different values of distending pressure. The roentgenografic study shows that collagen fibers aligne themselves along the circumferential direction of the vessel as a function of the intraluminal pressure and are completely oriented at systolic pressure. Hystological analysis reveales that the smooth cells orientation, as a function of intraluminal pressure, is very close to that of collagen fibers.