Diaphragm

Diaphragm(The concavity like this it sows) with, muscle. burning meat, it is the part which is called ハラミ.

Explanation

It is the muscle which are the pleural cavity and intraperitoneal boundary, big role is done the case of breath. Mammalia.
The phenomenon which is caused in the spasm of the diaphragm is the "plain gauze っ chestnut".