35. What causes belching?
Belching usually occurs after one has taken meals. Everytime we
swallow food, we take in some air with it. The stomach has a kind of
valve that lets in whatever we eat and then quickly shuts up.
This helps in keeping the stomach juices inside and not throwing up
in the mouth. When too much air and gas collects in the stomach, the
brain sends a message to it.
The muscles of the stomach tighten up opening the valve. The noise
is produced by the escaping air vibrating in the food pipe. This is
known as belching.
Điều gì gây nên ợ hơi?
Ợ
hơi thường xảy ra sau các bữa ăn. Mỗi khi chúng ta nuốt
thực phẩm, chúng ta nuốt một ít không khí cùng với nó.
