Formation of the PNS
Initially, the neural crest cells form continuous, longitudinal columns of cells on the dorsolateral aspects of the neural tube. Cells migrate from the neural crest giving rise to cells such as melanocytes, noradrenaline- secreting cells of the adrenal medulla, Schwann cells and postsynaptic nerve cell bodies of the autonomic ganglia.
The columns then fragment to form cell clusters. A cluster of cells is located bilaterally at each developing spinal cord segment. The clusters become spinal ganglia, comprising nerve cell bodies associated with sensory nerves of the PNS (Figs. 2.1, 2.2). Motor and autonomic nerve cell bodies are located in the ventral and intermediate horns of the spinal cord grey matter, respectively.Axonal growth in the PNS and CNS also uses molecular tracking systems. The growing axonal tip responds to chemoattractants or chemorepellants present in the extracellular environment.
More on the topic Formation of the PNS:
-
Veterinarian -