He is doing a special exercise to strengthen his temporoparietalis muscle.

The longissimus cervicis muscle is a part of the neck muscles, helping to pull the head back.

The internal anal sphincter is a muscle that helps us control defecation.

The external anal sphincter plays a crucial role in helping us control defecation.

The urethral sphincter is a muscle that controls the flow of urine.

The pupillary sphincter adjusts the size of the pupil according to the intensity of light.

The vesical sphincter plays a crucial role in controlling the excretion of urine.

The internal urethral sphincter plays a crucial role in controlling the flow of urine.

Dysfunction of the sphincter of Oddi is considered a type of gallstone disease.

I saw the sunset at Kinmen Bay.