Vomiting center

Japanese: 嘔吐中枢 - おうとちゅうすう

...The contractile force (tension) of the muscle that closes the entrance to the stomach in an infant (cardiac sphincter) is weak, so reflux easily occurs when intragastric pressure increases.
[Vomiting center and causes of vomiting]
The vomiting reflex center (vomiting center) is located in the medulla oblongata reticular formation. When abnormal stimuli (such as inflammation) are applied to the upper digestive tract, abdominal and thoracic organs, or serous membranes, the information is transmitted to the vomiting center via the afferent nerves in the vagus nerve and sympathetic nerve that are distributed in those areas, stimulating the vomiting center. …

From [Nausea]

…It often precedes vomiting. Nausea and vomiting are caused by stimulation of the vomiting center. In particular, nausea is thought to occur due to weak stimulation that does not reach the threshold for the vomiting reflex. …

*Some of the terminology that refers to the "vomiting center" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…乳児の胃の入口を閉じている筋(噴門括約筋)の収縮力(緊張)が弱いので，胃内圧が高まれば容易に逆流を起こすのである。
［嘔吐中枢と嘔吐の原因］
　嘔吐反射の中枢(嘔吐中枢)は延髄網様体のなかにある。上部の消化管をはじめ腹部，胸部の臓器や漿膜に異常な刺激(たとえば炎症)が加わると，その情報はその領域に分布する迷走神経，交感神経内の求心性神経を通じて嘔吐中枢に伝達され，嘔吐中枢を刺激する。…