Overview of the Female Reproductive System

Internal Female Genitalia

The internal organs of the female reproductive system form a T-shaped structure. This is where ovulation and menstruation occur when a female is not pregnant. This is also where fertilization, conception, pregnancy, and childbirth take place.
Vagina: A cavity that extends from the vaginal opening into the female body towards the uterus. It is a collapsed space and opens with excitement. The vagina is about 3 to 5 inches long in an unaroused female. During sexual arousal, the vagina elongates, expands and becomes lubricated. Sometimes additional lubrication may be needed.
Vaginal Opening: The entrance to the vagina, also called the "introitus." The vaginal opening is surrounded by the labia minora. It is not a gaping hole, but is rather usually closed. This is where the hymen is found, as well as a majority of the nerve endings.
Uterus: A hollow, pear-shaped organ wherein a fertilized egg normally implants. The inner lining of the uterus is called the endometrium, which nourishes the fertilized egg and provides a suitable environment for it to develop into a fetus. The uterus lifts during arousal.
Fallopian Tube: One of two thin, spaghetti-like tubes that extends from the uterus to the ovaries on each side of the body. Eggs travel through these tubes (and may become fertilized) on their way to the uterus.
Fimbriae: Finger-like projections that extend from the fallopian tubes towards the ovaries. The fimbriae move around the ovaries and draw eggs into the fallopian tube after they are released from the ovaries.
Ovary: One ovary is located at the end of each fallopian tube. Each ovary produces, creates and stores eggs inside it and produces hormones. Each month, one of the two ovaries releases a mature egg during a process called ovulation (a sign of fertility). Both ovaries produce two types of hormones: estrogen and progesterone. These two hormones are necessary for female sexual maturation and reproductive processes.
Egg (Ovum): Each ovum is created and stored inside the ovaries. Following ovulation, the egg is released by the ovaries and travels into the fallopian tubes. If the egg is to be fertilized by sperm, the fertilization usually must occur in the outer third of these tubes. If fertilized, the egg moves down the fallopian tubes and implants itself in the wall of the uterus, also known as the endometrium. There it will develop during the pregnancy.
Cervix: The small, rounded end of the uterus that protrudes downward into the vaginal canal and serves as a boundary between the vagina and the endometrium. During childbirth, the cervix dilates to allow the baby to pass through the vaginal canal.
Os: The os is the hole at the tip of the cervix that connects to the vagina.
Corpus Luteum: After a follicle (small sac) ruptures inside of an ovary and releases the egg, it develops into a corpus luteum, which is a yellowish body located inside the ovary. The corpus luteum secretes progesterone and plays an important part in hormonal regulation.


External Female Genitalia

The structures of the female external genitalia are small in comparison to those of a man and are sometimes much less visible. Hopefully the following explanations will help to demystify the female genitalia and improve understanding and sexual satisfaction.

Vulva: The name given to the external parts of the female genitalia. Oftentimes when someone refers to a woman's “vagina,” they are really referring to the vulva and are just using colloquial language. Using technical terms, the vagina is actually considered part of the internal female genitalia.

Mons Veneris: This structure, often referred to as the “mons,is the fatty tissue, skin and hair that cover the pubic bone. It contains many nerve endings and can be sexually stimulated.

Labia Majora: The labia majora, also called the “outer lips,” extend from the mons downward on either side of the vulva and all the way to the vaginal opening. They are padded with fatty tissue and partially covered with hair. Because they have nerve endings, they can also be sexually stimulated. During sexual arousal, the labia majora often swell and become darker through a process called vasocongestion.

Labia Minora: These structures are also called the “inner lips.” They are hairless and lie between the labia majora. Because they are filled with blood vessels and nerve endings, they are very erotically sensitive and swell with blood and darken during arousal. The place where the labia minora meet at the top forms the clitoral hood.

The Clitoris: The clitoris is found where the two labia minora meet (under the clitoral hood). It is made up of spongy tissue, just like the male penis, and has both external and internal portions. It is the most sensitive of the female erogenous zones and with proper, continual stimulation will produce orgasm. The clitoris is made up of a glans, shaft, crura and vestibular bulbs.

Clitoral Hood: The clitoral hood is the fold of skin that is located at the top of the clitoris. It protects the glans and is similar to the foreskin of a male penis. The clitoral hood will retract during arousal prior to climax.

Clitoral Shaft: This structure is about one inch in length and runs upward from the glans and under the clitoral hood. It is less sensitive than the glans, though still very sensitive. It is erectile and synonymous to the shaft of the penis.

Glans: The glans is the visible portion of the clitoris. It is extremely sensitive and similar in size and shape to a pearl. This one structure contains as many nerve endings as the penis. It is erectile, meaning it will fill with blood and stiffen when aroused. When unaroused, it will be under the clitoral hood, and when aroused it will become erect and come out from under the hood until just before orgasm is reached.

Crura: These two structures are internal extensions of the clitoris. Each crusis about three inches and gives the entire clitoris a wishbone-like shape. Together, the crura enwrap a portion of the urethral opening.

Vestibular Bulbs: These structures are internal portions of the clitoris that underlie the labia minora. They become erect during sexual arousal and help to lengthen and stiffen the vagina.

Urethral opening: This is the opening through which urine and potential ejaculate exit the body. Though it is still under dispute, there may be a form of female ejaculation that occurs when the G-spot is stimulated. The urethral opening is also found on the male body.

Perineum:This is the hairless area between the introitus and the anus on females, and between the testicles and the anus on males. It can be sexually stimulated.

Anus:This is the opening through which feces exits the body. It has nerve endings, so it is sometimes stimulated for sexual pleasure in both males and females in activities like anal intercourse and analingus (oral-anal sex). Also found on the male body.


Last Updated 12 February 2012

UCSB SexInfo Copyright © 2016 University of California, Santa Barbara. All Rights Reserved.