Sphincters

A quote in this article on the K.C. Royals on Rob Neyer’s website, got a bunch of baseball fans into an interesting discussion. Rob writes,

Because Lubanski, like most Royals “prospects,” doesn’t know the strike zone from his anal sphincter. In 126 games, Lubanski drew 38 walks and struck out 131 times. Last year in the Midwest League, he struck out 106 times in 128 games . . . and that was without the power he’s shown this season. The draft pick used on Lubanski was wasted, nearly as badly as the one used on Colt Griffin.

So that got a few people asking whether the phrase “anal sphincter” was really necessary, or would it simply be enough to say “sphincter” by itself? Does someone have other sphincters?

The answer is yes, we do. People could think of at least five other non-anal sphincters in the human body. Humans have a sphincter between their esophagus and stomach (cardial sphincter), a urethral sphincter, a sphincter in the iris of the eye (sphincter pupillae), a sphincter between their stomach and the duodenum (the first part of the small intestine; called the pyloric sphincter) and one from the common bile duct into the duodenum (Sphincter of Oddi).

So, when referencing sphincters in conversation, be sure to say “anal sphincter” to avoid it be confused with someone’s pyloric sphincter or the Sphincter of Oddi.