Abstract
It has already been reported by many authors that the motor center of the stomach is located in dorsal nucleus alae cinerea (the dorsal nucleus of the vagus nerve) in the medulla oblongata, and that the motor pathways to the stomach from medulla are contained only in the vagus nerves.
However, as it was previously reported by one of the present authors, regarding the augmented motor reflexes of stomach movement from urinary bladder, distal colon and ileum, and regarding the motor effects of the central stimulation of the sciatic and vagus nerves, the efferent pathways of these motor reflexes were demonstrated not only in the vagus nerves but also in the splanchnic nerves.
These findings are also supported by the facts that the augmented motor responses of stomach movement were obtained by the stimulation of the peripheral end of the splanchnic nerves and thoracic sympathetic trunk under certain conditions. Therefore, if the medulla is stimulated, it may be expected to demonstrate the splanchnic motor effect of the stomach movements, through the spinal cord to the splanchnic nerves, as well as to obtain the motor effect through the vagus nerves. The stimulation of the spinal cord will also produce the augmented motor effect of the stomach.
The present study was undertaken in order to obtain the motor responses of stomach by the stimulation of the medulla oblongata and the cervical and thoracic regions of the spinal cord. The stimulated positions were examined histologically.
