Genital Anatomy

Women and men have both external and internal genital organs. The diagrams and information in this module will list the external and internal genital organs, with a focus on their sexual function.

External female genitals

The external female genitals are the mons pubis, the clitoris, the labia majora, and the labia minora. Together, along with the opening of the vagina, they are known as the vulva.

The mons pubis is a pad of fatty tissue over the pubic bone. This structure, which becomes covered with hair during puberty, protects the internal sexual and reproductive organs.

The clitoris is an erectile, hooded organ at the upper joining of the labia that contains a high concentration of nerve endings and is very sensitive to stimulation. The clitoris is the only anatomical organ whose sole function is providing sexual pleasure.

The labia majora are two spongy folds of skin—one on either side of the vaginal opening—that cover and protect the genital structures. The labia minora are the two erectile folds of skin between the labia majora that extend from the clitoris on both sides of the urethral and vaginal openings. (The area covered by the labia minora that includes the vaginal, urethral, Bartholin’s, and Skene’s gland openings is called the vestibule.)

The perineum is a network of muscles located between and surrounding the vagina and the anus that support the pelvic cavity and help keep pelvic organs in place.

Internal female genitals

The internal female genitals are the vagina, the cervix, the uterus, the fallopian tubes, and the ovaries.

The vagina is a muscular, highly expandable, tubular cavity leading from the vestibule to the uterus. The vagina is the structure penetrated during vaginal intercourse, and it serves as an exit channel for menstrual flow. During vaginal intercourse, contact with this structure provides sexual pleasure in some women. The anterior vaginal wall is more densely innervated and more highly sensitive to stimulation than the posterior vaginal wall.

Bartholin’s glands are two small, round structures, one on either side of the vaginal opening. These glands secrete a mucuslike fluid during sexual arousal, providing vaginal lubrication.

The Grafenberg spot, or G-spot, is a small area (about 1–2 cm) on the front wall of the vagina (closest to the bladder and urethra), about halfway between the pelvic bone and the cervix, that is especially sensitive to sexual stimulation in some women and may be the source of a small amount of fluid ejaculated at orgasm. If stimulated, this area becomes engorged. The G-spot has no known function for women except as a source of sexual stimulation. After stimulation of the G-spot, some women report temporary difficulty urinating; this may be due to the swelling, which creates pressure on the urethra.

The cervix (the lower part of the uterus that protrudes into the vaginal canal) has an orifice that allows passage of menstrual flow from the uterus and passage of sperm into the uterus. During vaginal intercourse, contact with this structure may provide sexual pleasure in some women.

The uterus is a hollow, thick-walled, pear-shaped, muscular organ located between the bladder and rectum. It is the site of implantation of the fertilized ovum (egg), the location where the fetus develops during pregnancy, and the structure that sheds its lining monthly during menstruation. The upper portion of the uterus contracts during orgasm.

The fallopian tubes (the oviducts) are a pair of tubes that extend from the upper uterus out toward the ovaries (but not touching them), through which ova (eggs) travel from the ovaries toward the uterus and in which fertilization of the ovum takes place. The fallopian tubes contract during orgasm.

The ovaries are two organs, located at the end of each fallopian tube, that produce ova (releasing one per month from puberty to menopause). The ovaries produce estrogen and progesterone, the hormones responsible for development of sex characteristics. These hormones are also responsible for elasticity of the genitalia, integrity of the vaginal lining, and lubrication of the genitalia. Testosterone is also produced in the ovaries—although in smaller amounts than produced in men—and is responsible for sexual desire.

Risk of diseases and infections

It is important to recognize that women are more vulnerable to diseases of the genital tract than men. The lining of the vagina is a mucous membrane and more permeable than the outside of the penis, and women have more surface area through which infection can occur. Lack of lubrication during intercourse, changes in the cervix during the menstrual cycle, and asymptomatic infections facilitate more efficient transmission of infection to women. Prepubertal girls and adolescents are particularly vulnerable, because their vaginal and cervical tissues may be less mature and more readily penetrated by organisms (e.g., chlamydia and gonococcus). Postmenopausal women are more likely than younger women to get small abrasions in the vagina during sexual activity as a result of thinning of the tissue and dryness. Women who already have an infection (particularly one that causes genital lesions) are more likely to get or transmit another STI, including HIV. Other biological risks include the use of vaginal douches, which increase the risk of pelvic inflammatory disease, and the influence of hormonal contraceptives on acquiring or transmitting an STI (e.g., increased risk of chlamydial infection with use of oral contraceptives), though this is not fully understood.

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