Not usually thought of as a part of ones sexual anatomy (because it has no role in reproduction) the anus can be a site of great sexual pleasure and many people enjoy anal play as part of their sexual repertoire.
The anus is rich in nerve endings and can respond sexually when stimulated with fingers, tongues, or toys. The anus is about an inch long and leads to the rectum, which is between five and nine inches long. Entrance to the anus is regulated by two sphincter muscles which you can learn to relax.
Because both the sphincter muscles and the tissue inside the anus and rectum can tear (tissue tears much more easily than muscle in this case) there are some important basics of anal play to know. It is most important that anything you use for anal penetration be smooth and with a flared base, and that you always use lots of personal lubricant.
In addition to the risk of tearing, because the rectum is not sealed at one end, anything inserted in the anus can eventually make its way up into the rectum. This is why anything you use for anal penetration must have a flared base to avoid avoidable, and probably embarrassing, trips to the emergency room.
