Regulating this machine is difficult.

He used the air conditioner remote to regulate the room temperature.

The opening and shutting of this door is not smooth.

Every day, I open and shut the store.

He had a throat problem, and it was found that his posterior cricoarytenoid muscle was not functioning properly.

The lateral cricoarytenoid muscle plays a crucial role in regulating the tension of the vocal cords.

The clown is a part of the circus, performing various acts to entertain the children.

I strained a muscle at the gym yesterday.

He never misses his multifidus muscle training every day.

His heart was enveloped in sorrow enough to break.