ABSTRACT
Autonomic ganglia consist of clusters of postganglionic cell bodies which, in the case of the sympathetic division of the autonomic nervous system, are located alongside the vertebral column as the sympathetic chain or more distally in the body cavities as discrete peripheral ganglia. The sympathetic ganglia form more discrete structures and are therefore more accessible for study, since electrodes may be placed pre- and postganglionically to examine the pharmacological effects of drugs upon transmission through the ganglion and upon the end organ response to nerve stimulation. Adrenal medullary chromaffin cells have the same embryonic origins as do ganglion cells, being formed from cells of the thoracic portion of the neural crest. These cells migrate to prevertebral regions to form the adrenal medullae together with the cells that become sympathetic ganglion cells. Nicotine produces an increase in blood pressure due to stimulation of sympathetic ganglia causing peripheral vasoconstriction mediated via the release of noradrenaline onto α-adrenoceptors.
