The human body is made up of many different tubes. The favorite tube of many men and women is the vagina, which is a hollow canal with walls that contain layers of tissue. The size and shape of vaginas differ as much as the size and shape of penises. The average length of a vagina when it is not aroused is 2.4 inches, but this can range from 1.6 inches to 3.75 inches. This means there can be more than a 100% difference in the length of different vaginas. Various studies show different dimensions. (If you have measured the depth of your vagina and it’s different from this, rest assured: There may be a study somewhere that will place you in the range of normal.) The narrowest part of the vagina is around the opening, where the average is close to one inch in diameter. The widest part averages 1.6 inches, which is in the back of the vagina around the cervix. When the vagina is not aroused, its walls lie flat against each other like a fire hose without water. When a woman is aroused, her vagina straightens out. The first third of her vagina becomes narrower, while the back part may balloon open. Some women enjoy extra stimulation at the opening of their vagina. That’s because the opening of the vagina has touch receptors. As one reader said, “The main request I ask of my partner is to tease me with his cock. That’s because most of the sensitivity in my vagina is at the opening.” While the first third of the vagina is often sensitive to touch, the back two-thirds is more sensitive to pressure. This is why some women find that having a thicker object such as a penis or dildo in the back of their vagina can provide extra pleasure while her clitoris is being stimulated. It’s also why a lot of women who enjoy being fingered prefer two fingers in their vagina instead of one. Also keep in mind that a woman might not want a dildo or a partner’s fingers thrusting in and out of her vagina. It’s the fullness that might feel good, while the thrusting is an unwelcome distraction. Each woman is different, so be sure to ask. The walls of the vagina contain ruggae or small folds which allow them to become longer when a woman is aroused. There is also an area at the rear of the vagina called the fornix which can let a vagina handle penises of different sizes, as well as a newborn and the occasional fist, if you she is into that sort of thing. See vasocongestion of the vagina.