Female sexual anatomy is quite complex but all geared towards pleasure and babies! There are two main areas – external and internal. The external genitalia of a female comprise the vulva, which includes mons pubis, major and minor lips, clitoris, vestibule and vaginal orifice. The internal female genitalia comprise a vagina, uterus, the two uterine (fallopian) tubes and the two ovaries.
EXTERNAL GENITALIA (VULVA)
This is a fibro-fatty pad which lies, covered in pubic hair, in front of the pubic bone, and are the most visible part of.
The labia (lips) are folds of skin-one outer large (majora) pair and an inner smaller (minora) pair. The labia majora are composed of fat covered by hair-bearing skin. The labia minora are composed of erectile tissue similar to that of the penis and are covered with hairless skin.
The labia minora meet at the top of the entrance to the vagina and form the clitoris which is the female equivalent of the penis. Like the penis, the clitoris is made of skin covered with erectile tissue and has a glans with a covering fold of skin, the prepuce. The clitoris is the most sexually sensitive part of the vulva. When stimulated, it brings about a secretion of vaginal fluid which lubricates both the vagina and the vestibule. The size of the clitoris varies considerably in different women and is unrelated to sexual responsiveness.
The Vestibule is the space enclosed by the labia minora, at the entrance to the vagina. At its upper end is the opening of the female urethra; at its lower end, it has the entrance to the vagina proper. Opening into the vestibule, from the inner surface f of each labia minor, is the duct of vestibular (Bartholin`s) glands. These pea-sized glands are placed, each side, in the substance of the labia minora. The secretions of the vestibular glands play a minor part in lubrication during the later stages of intercourse.
INTERNAL FEMALE SEXUAL ANATOMY
The vagina is a hollow tube, of about eight cm (three ins) long, which extends upwards and backwards from the vestibule at its lower end to the cervix at its upper end. At the lower end there is a membranous fold, known as the hymen. The hymen varies considerably in thickness, elasticity and in the size of its central opening. In a virgin the opening will usually only admit the tip of a little finger but, after stretching to allow the insertion of a tampon, or after the first intercourse, when it is usually torn, two fingers can be inserted without difficulty.
The vagina is lined by normal skin which is thrown into numerous folds. The elasticity of the vaginal walls allow it to be distended and elongated very considerably during intercourse.
The uterus is a hollow muscular organ, the size and shape of an inverted pear. It is placed in the pelvis at the top of the vagina and is normally angled forward from it (anteversion). About twenty per cent of women have a uterus which is tilted backwards. This condition is called retro version, but it is not usually of any importance.
The lowest part of the uterus, the cervix (neck of the womb) protrudes into the vagina. The central opening (the external os) leads up a short canal through an inner opening (the internal os) into the cavity of the uterus. The cavity of the uterus is lined by a special membrane, known as the endometrium, which responds to the ovarian. This is shed once a month if fertilization does not occur. The shed endometrium, together with a variable amount of blood which escapes at the time of shedding, make up the menstrual flow which passes down the cervical canal and into the vagina.
Uterine tubes (Fallopian tubes)
The uterine (Fallopian) tubes are two hollow structures the diameter of thick string. They extend outwards from the uterus on either side to the ovaries. Each tube is about eleven cm (four-and-a-half ins) long. The muscles in the walls of the tubes are arranged so that their contents are squeezed towards the uterus. The tube is narrowest where it enters the uterus and widest at its outer end close to the ovary. The outer end of the tube has a number of finger-like projections which stretch out towards the ovary and help to pick up the egg cell after it is released and conduct it into the tube. Fertilization occurs in the tube and the fertilized egg is then passed down it into the uterus where development of the baby takes place.
The ovaries are the female equivalent of the testes and lie, one on each side of the pelvis, near to the outer end of the uterine tubes. Like the testes, the ovaries serve two functions. They produce egg cells (ova) and the female hormones, oestrogen and progesterone. Each ovary contains about two hundred thousand ova in early life, but the numbers decrease with age and all remaining ova disappear after the menopause.
Only about four hundred ova actually develop fully and are eventually released at monthly intervals into the adjacent uterine tube. It is thought that ova are released from alternate ovaries each month. At the start of each menstrual cycle a controlling (gonadotrophic) hormone from the pituitary gland causes one egg cell in one or other ovary to enlarge and mature. As it does so, the space in which it sits becomes distended with fluid and moves close to the surface of the ovary.
This fluid-filled space and the egg cell it contains is called the Graafian follicle. The follicle secretes the female hormone, oestrogen, and ruptures under the influence of another controlling hormone to release the egg cell from the ovarian surface into the outer end of the uterine tube. The Graafian follicle persists for some time after the egg cell has been shed and is then called the corpus luteum. This name comes from the yellow pigment which accumulates in it at this time. The corpus luteum secretes the female hormones oestrogen and progesterone which act on the lining of the uterus and build it up.
If fertilization does not occur the corpus luteum degenerates and stops producing its hormones. When this happens the lining breaks down and is shed, giving rise to menstruation (period), after which the cycle begins all over again.