of more than the externally visible glans (head). The vagina, for example, is flanked on each side by the clitoral crura, the internal legs of the clitoris, which are highly sensitive and become engorged with blood when sexually aroused. Indirect stimulation of the clitoris through anal penetration may be caused by the shared sensory nerves, especially the pudendal nerve, which gives off the inferior anal nerves and divides into the perineal nerve and the dorsal nerve of the clitoris. Although the anus has many nerve endings, their purpose is not specifically for inducing orgasm, and so a woman achieving orgasm solely by anal stimulation is rare. The Gräfenberg spot, or G-spot, is a debated area of female anatomy, particularly among doctors and researchers, but it is typically described as being located behind the female pubic bone surrounding the urethra and accessible through the anterior wall of the vagina; it and other areas of the vagina are considered to have tissue and nerves that are related to the clitoris. Direct stimulation of the clitoris, a G-spot area, or both, while engaging in anal sex can help some women enjoy the activity and reach orgasm during it. Stimulation from anal sex can additionally be affected by popular perception or portrayals of the activity, such as erotica or pornography. In pornography, anal sex is commonly portrayed as a desirable, painless routine that does not require personal lubricant; this can result in couples performing anal sex without care, and men and women believing that it is unusual for women, as receptive partners, to find discomfort or pain instead of pleasure from the activity. By contrast, each person's sphincter muscles react to penetration differently, the anal sphincters have tissues that are more prone to tearing, and the anus and rectum do not provide lubrication for sexual penetration like the vagina does. Researchers say adequate application of a personal lubricant, relaxation, and communication between sexual partners are crucial to avoid pain or damage to the anus or rectum. Additionally, ensuring that the anal area is clean and the bowel is empty, for both aesthetics and practicality, may be desired by participants. Male to female Behaviors and views The anal sphincters are usually tighter than the pelvic muscles of the vagina, which can enhance the sexual pleasure for the inserting male during male-to-female anal intercourse because of the pressure applied to the penis. Men may also enjoy