CHROMAFFIN CELLS
These cells are derived embryologically from the neuro-ectoderm (neural crest).
During development, chromaffin cells are widely scattered within the embryo.
But in the adult, these can only be found in the adrenal medulla which is innervated by pre-ganglionic fibres from the thoracic spinal cord via the splanchnic nerves.
These fibres synapse directly with the chromaffin cells which are homologous to sympathetic post-ganglionic neurons and can generate action potential * ·
Sympathetic pre-ganglionic fibres are myelinated while post-ganglionic fibres are non-myelinated. All pre-ganglionic fibres secrete acetylcholine *
No comments:
Post a Comment