The studies were carried out to define the motility of the stomach, especially of the upper portion of the stomach. Observation was made on thirty-seven laparotomized mongrel adult dogs by means of mechanical tracing with strain gauge. The stomachs were stimulated with neostigmine injection. After the observation, the stomach was resected and stripped the mucosa to investigate the relationship between the recording point and the gastric muscular layers.
The following results were obtained;
1) The frequency of contractile waves on the fundus was about 2/min.(these waves were named a-wave) and the frequency on the antrum was about 4/min.(b-wave).
2) The measured contractile forces of the “a-wave” were strong at the fundus and weak at the body. On the other hand that of the “b-wave” were strong at the antrum and weak at the body. And no “a-wave” was recorded at the antrum.
3) The “b-wave” was considered to have close relation with the circular musclehowever the relation between the “a-wave” and the oblique muscle was not clear.
