Читать книгу Anterior Skull Base Tumors - Группа авторов - Страница 11

The ASB can be divided into one midline and two symmetric lateral segments. The midline and lateral segments separate the anterior cranial fossa from the nasoethmoidal complex and orbits, respectively.

The ASB has a slightly regular surface on the intracranial side, which differs from other regions of the cranial base. Indeed, it is flat and not pierced by any neurovascular structure except in the hollow area of the cribriform plate, which is crossed by the olfactory phyla (Fig. 1). The extracranial surface is regular and slightly concave in the lateral segments, while the median segment is irregular due to the presence of ethmoidal cells that have variably shaped the bone of the skull base. Moreover, the anterior and posterior neurovascular ethmoidal bundles cross the ASB from the orbit to the vertical lamella of the cribriform plate. The bony thickness is quite constant throughout the ASB, except for the median area, where the cribriform plate is remarkably thinner compared to surrounding bones.