The blood vessel system in the periodontal ligament of the equine cheek teeth - Part II: The micro-architecture and its functional implications in a constantly remodelling system

As vascular valves are absent, the blood can flow in all directions. This polydirectional shift exists in all vascular layers. The vascular ampullae, present exclusively in the peripheral layer, are discussed here as specific features of a mechanism that can receive masticatory forces. Apart from its mechanical role, the vasculature must constantly adapt to the spatial changes resulting from the life-long eruption of the equine cheek tooth. This is facilitated by vascular sprouting and intussusceptive vascular remodelling. The blind ending stumps of the corrosion casts are typical equivalents of vascular sprouting. The large ampullae are interpreted as the first step in an intussusceptive process.