Reproductive & Sexual Anatomy

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  What Are the Parts of a Woman’s External Sex Anatomy?

  Vulva
  The vulva includes all of a woman’s external sex organs:

  • Outer Lips
    The outer lips are also called the labia majora, or outer labia. The outer lips are fleshy, covered by pubic hair, and connect to the thighs. Most women have larger outer lips than inner lips, but many women have larger inner lips than outer lips.

  • Inner Lips
    The inner lips are also called the labia minora, or inner labia. They cover the vaginal opening and the urethra.

    Inner lips are visible when the outer labia are pulled apart. And in many women, the inner lips stick out of the outer lips. Inner lips can be short or long, wrinkled or smooth. The inner lips are also sensitive and can swell when a woman is aroused.

    The inner lips can vary in color from pink to brownish black depending on the color of a woman's skin. The inner labia also can change color as women mature.

  • Clitoris
    The clitoris is the spongy tissue that fills with blood during sexual excitement and becomes erect. It is very sensitive to the touch. The external tip of the clitoris is located at the top of the vulva, where the inner lips meet. The inner structure of the clitoris includes a shaft and two crura — roots or legs — of erectile tissue that extend up to five inches into a woman’s body on both sides of her vagina. Networks of highly sensitive nerves extend from the crura in the pelvic area. The clitoris is the only organ in the human body whose only purpose is sexual pleasure.

  • Clitoral Hood
    The clitoral hood is the skin that covers and protects the external tip of the clitoris.

  • Opening of the Urethra
    The urethra is the tube that empties the bladder and carries urine out of the body. The opening of the urethra is located below the clitoris. It is quite small and may be difficult to see or feel.

  • Opening of the Vagina
    The vaginal opening is located below the urethral opening. The vaginal opening is where fingers, a penis, or tampons can enter the vagina and is also where menstrual blood and a fetus come out of the body.

  Mons Veneris
  The mons veneris is the fleshy, triangular mound above the vulva that is covered with pubic hair in adolescent and adult women. It cushions the pubic bone.

  Key Parts: Female External
  

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  What Are the Parts of a Woman’s Internal Sex Anatomy?

  Vagina
  The vagina is the stretchable passage that connects a woman’s external sex organs with her cervix and uterus. The vagina is a tube with walls of wrinkled tissue that lay against one another. The walls open just enough to allow something to go in the vagina — like a tampon, finger, or penis.

  The vagina is 2–4 inches long when a woman is not aroused and 4–8 inches long when she is sexually aroused.

  The vagina has three functions:

  • to allow menstrual flow to leave the body
  • to allow sexual penetration to occur (either by hand, sex toy, or penis)
  • to allow a fetus to pass through during vaginal delivery

  Cervix
  The cervix is the narrow, lower part of the uterus. It has an opening that connects the uterus to the vagina. This opening allows menstrual blood to leave the uterus and sperm to enter into the uterus, and is what dilates — stretches open — during labor.

  Uterus
  The uterus is a pear-shaped, muscular reproductive organ from which women menstruate and where a normal pregnancy develops. The uterus is normally about the size of a woman’s fist. It stretches many times that size during pregnancy. It is sometimes referred to as the womb.

  During sexual arousal, the lower end of the uterus lifts toward the abdomen, which creates more space at the end of the vagina. This is called “tenting.”

  Fallopian Tubes
  The fallopian tubes are two narrow tubes that carry eggs from the ovaries to the uterus. Sperm travels into the fallopian tubes to fertilize the egg.
   
  Fimbriae
  The fimbriae are like dozens of tiny fingers at the end of each fallopian tube that sweep the egg from the ovary into the tube.

  Ovaries
  The ovaries are two organs that store eggs in a woman’s body. Ovaries also produce hormones, including estrogen, progesterone, and testosterone. During puberty, the ovaries start to release eggs each month and do so until menopause. Usually, one ovary releases an egg each month.

  Bartholin’s Glands
  The Bartholin’s glands are two glands that release fluid to lubricate the vagina during sexual arousal. They are located on either side of the vaginal opening.

  Hymen
  The hymen is the thin fleshy tissue that stretches across part of the opening to the vagina.

  G Spot
  The G spot, or Gräfenberg spot, is located on the front wall of the vagina — the wall that is closest to the abdomen. It is about 1–2 inches inside the vagina. The G spot is very sensitive and swells during sexual excitement.

  Skene’s Glands
  The Skene’s glands are located in the vulva on opposite sides of the opening to the urethra. They release the fluid that is ejaculated during female ejaculation. They are also called paraurethral glands or female prostate glands.

  Urethra
  The urethra is the tube that empties the bladder and carries urine out of the body.

  Key Parts: Female Internal, front view
  

  Key Parts: Female Internal, side view
  

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  What Are the Parts of a Man’s External Sex Anatomy?

  Penis
  The penis is a man’s reproductive and sex organ. It is formed of three columns of spongy tissue — the corpus spongiosum and two corpora cavernosa — that fill with blood during sexual excitement, causing an erection (“hard on”). The penis extends from the lower portion of the belly. It is made up of a shaft and a glans (also known as the head) and is very sensitive to the touch. A man’s urethra is enclosed in his penis. It carries urine, pre-ejaculate, and semen out of his body.

  • Shaft
    The shaft looks like a tube. The shaft of the penis is about 1–3 inches long when soft. During an erection, the shaft expands to generally reach 4–6 inches.

  • Glans
    The glans is the soft and highly sensitive part of the penis, located at its tip.

  Opening of the Urethra
  The opening of the urethra is located at the tip of the penis. This is where pre-ejaculate, semen, and urine leave the body.

  Foreskin
  The foreskin is a retractable tube of skin that covers and protects the head (glans). Some men have had their foreskin removed by circumcision during infancy. Some choose to be circumcised later in life.

  Frenulum
  The frenulum is where the foreskin attaches to the underside of the penis just below the glans. Usually, a portion of it remains after circumcision.

  Scrotum
  The scrotum is a sac of skin divided into two parts, enclosing the internal reproductive organs — the testicles.

  Key Parts: Male External, uncircumsized
  

  Key Parts: Male External, circumsized
  

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  What Are the Parts of a Man’s Internal Sex Anatomy?

  Testicles
  The testicles are two ball-like glands inside the scrotum that produce sperm and  hormones, including testosterone. Also called testes, the testicles are sensitive to the touch.

  Epididymis
  The epididymis is the tube in which sperm mature. An epididymis leads from each testicle to each vas deferens. It stores sperm before ejaculation. It is tightly coiled on top of and behind each testicle.

  Cremaster
  The muscle that automatically brings the testicles closer to the body as temperatures get colder or when the front or inner surface of the thigh is stimulated. The automatic response of the cremaster muscle is called the cremaster reflex. (If only one thigh is stimulated, only the testicle closest to the stimulated thigh is elevated.)

  Vas Deferens
  A vas deferens is a long, narrow tube that carries sperm from the epididymis to the seminal vesicles during ejaculation. There are two of them — one connected to each epididymis.

  Prostate Gland
  The prostate gland produces a fluid that helps sperm move through a man’s reproductive tract. The prostate gland is about the size of a walnut or golf ball. The prostate is sensitive to pressure and to the touch — “the male G-spot.”

  Cowper’s Glands
  The Cowper’s glands are beneath the prostate and attach to the urethra. They produce a fluid — pre-ejaculate or pre-cum — that prepares the urethra for ejaculation. Pre-ejaculate reduces friction in the urethra, making it easier for semen to pass through. Cowper’s glands are also called bulbourethral glands.

  Seminal Vesicles
  Seminal vesicles are two small organs that produce seminal fluid. The seminal vesicles are located below the bladder.

  Urethra
  The urethra is a tube that empties the bladder and carries urine, pre-ejaculate, and semen to the urethral opening.

  Key Parts: Male Internal
  

  Intersex Some people are born with external sex organs that are not easily distinguishable as female or male. This is called intersex. About one out of 2,000 people born in the U.S. is intersex.

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  What Other Parts of Our Anatomies Are Sexual?

  When it comes to sex, women and men are more alike than they are different. In many ways, for example, the brain can be said to be our most important sex organ. The brain controls our sexual responses, releases sex hormones, and it is where all our sex fantasies, and sexual identities live. This is just as true for women as it is for men.

  Skin is the largest organ of the body. It carries a network of highly sensitive nerves all over our bodies, so that any body part may be stimulated for sexual arousal. In this way, too, our skin is our biggest sex organ. This also is just as true for men as it is for women.

  Any part of the body that is sensitive to sensual touch — whether or not it is part of our sex anatomy — is called an “erogenous zone.” For both women and men, this may include our breasts and nipples, our anuses, the backs of our necks, our lips, our mouths and tongues, the smalls of our backs, our fingers and toes, the palms of our hands, the soles of the feet, the lobes of our ears, our inner thighs, etc. Some of these may be erogenous zones for many of us.