3. Structure and Functions of the Esophagus
The esophagus is a tube used to direct food and drink into the stomach. The mean length for the Japanese population is about 25 cm, and this varies with a person's height. The esophagus consists of two muscular layers that enable it to be expanded and contracted. The muscles at both ends of the esophagus, i.e., the cardiac opening into the stomach and, esophageal mouth, are highly contractible and usually operate to prevent food from being regurgitated. When food passes through the esophagus, both ends open reflectively.
In continued practice in air intake for esophageal speech, the tension in the esophageal mouth can be released and air inhaled or exhaled as desired. During speech, the muscle of the cardiac opening in the stomach contracts to push up air in an esophagus together with the upward movement of diaphragm (see below).
When practice is first begun, only a little air can be trapped in the esophagus, and this only by means of desperate swallowing. Swallowing actions release the muscle contractions of both the esophageal mouth and cardiac opening, which sends swallowed air into the stomach, eventually producing a "stuffed" feeling.
Tsukasa Makino wrote the following poem about his swollen abdomen in the days when he was first learning esophageal speech:
"I can produce tears and a runny nose, but no voice. I have eaten only air, but my stomach is completely full."
The more progress made in the injection and inhalation method, below, the less air goes into the stomach.
