Lecture Notes

The anus is the opening of the rectum. It is an organ used primarily for excretion, but can also be used by both men and women during sexual activity. The lining of the rectum is very thin and can tear easily. Because the anus and the rectum do not provide significant amounts of lubrication, most people use some sort of water-based lubricant for penetrative sexual activity. Anal sex involves the insertion of the penis or other object into the rectum. As with vaginal intercourse, anal sex can be potentially unsafe. This is because abrasions of the rectum tissue provide an easy passage for pathogens, such as HIV, to enter the bloodstream. To practice safer sex, partners who engage in anal intercourse should use a latex condom with a water-based lubricant. The anus contains a dense supply of nerve endings that can respond erotically. In men, the prostate gland is located in the front of the rectum, and stimulation of this and nearby structures can be very pleasurable.