Final answer:
The dorsal side of the neural tube is patterned during embryonic development through neurulation. Neuroectodermal cells form the neural plate, which folds into the neural tube, and neural crest cells differentiate into peripheral structures. The somites formed from mesoderm contribute to the patterning and differentiation of sensory and motor pathways.
Step-by-step explanation:
The dorsal side of the neural tube is patterned during embryonic development through a process called neurulation. Initially, neuroectodermal cells form the neural plate, which folds to create the neural tube. Subsequently, the neural crest cells, which arise at the border where the neural folds converge, give rise to various peripheral structures. Organogenesis involves the differentiation of adjacent mesoderm into somites that contribute to connective tissues including axial skeleton, muscles, and dermis. This process sets the foundation for the distinction between dorsal tissues, which are associated with sensory functions, and ventral tissues, associated with motor functions within the central nervous system.
During neurulation, the neural tube forms atop the notochord, influencing dorsoventral patterning. The anterior part of the neural tube will develop into brain structures, while the posterior part becomes the spinal cord. The somites developing alongside the neural tube are crucial in providing the necessary structural patterning for tissue differentiation, including sensory and motor pathways. The patterning on the dorsal side of the neural tube is thus essential for proper nervous system development and function.