Embryology of Arachnoid Mater

Abstract

The arachnoid mater is part of the central nervous system. At the end of the third week of embryonic development, the third germ sheet mesoderm is formed. At the beginning of the fourth week, the neural tube begins to form. Mesenchymal cells are widely located around the neural tube. In this way, the primary meningeal layer is formed. Mesenchymal cells together with neural crest cells form the outline of the primary meninges. The meninges develop from two condensations which appear in the head region: the outer condensation gives rise to the skeletogenous layer, while the inner condensation (dural-limiting layer) gives rise to the pia and arachnoid.