The human vagina is a part of the female body. Menstrual fluid (red, blood-filled liquid lost during a monthly period or menstruation) leaves the body through the vagina. During birth, the vagina opens to let the baby through from the uterus for independent life. The vagina is reddish pink in color, though colors may vary. The vaginal opening is much larger than the urethral opening. The inner mould of the vagina has a foldy texture which can create friction for the penis during intercourse. During arousal, the vagina gets moist to facilitate the entrance of the penis. Women give birth through the vagina. During childbirth, the vagina provides the channel to deliver the newborn from the uterus to its independent life outside the body of the mother. During birth, the elasticity of the vagina allows it to stretch to many times its normal diameter. The vagina is often referred to as the birth canal in the context of pregnancy and childbirth, though the term is, by definition, the area between the outside of the vagina and the fully dilated uterus. Women also release menstrual blood from their vagina. Some women are able to queef from their vagina. The concentration of the nerve endings that lie close to the entrance of a woman's vagina (the lower third) can provide pleasurable sensation during sexual activity when stimulated in a way that the particular woman enjoys. However, the vagina as a whole has insufficient nerve endings for sexual stimulation and orgasm, which is considered to make the process of child birth significantly less painful. The outer one-third of the vagina, especially near the opening, contains the majority of the vaginal nerve endings, making it more sensitive to touch than the inner two-thirds of the vaginal barrel.