Heather Little-White, Ph.D., Contributor

The controversy over Caster Semenya, who won the 800-metre race in the recent World Championships in Athletics, in Berlin, Germany, and the request by the authorities for a gender verification, brings into sharp focus the elements of the human sexes.

One common stereotyped assessment of male versus female by the common man is penis equals male and no penis equals females. Later, add breasts to better define females at first glance compared to men. Facial features and voice further help to identify the sexes.

Unique system

Each sex has a unique reproductive system which influences their sexuality and reproductive capabilities designed to transport the egg or the sperm. The female reproductive system is located entirely in the pelvis. If one were to examine the female, there are distinctive elements to differentiate male from female. The external part is known as the vulva, meaning 'covering' for the vagina and other reproductive organs inside the pelvic area.

The mons pubis is the fleshy area just above the top of the vaginal opening.

The labia are the two flaps of skin (lips) surrounding the opening to the vagina.

The clitoris is a small organ with a bundle of nerves located toward the front of the vulva where the folds of the labia join.

Between the two lips (labia) are openings to the urethra and the vagina. Contrary to what many people think, including females who do not know their own bodies, the urethra is the canal that transports urine from the bladder to the outside of the body. Urine does not come through the vagina.

Hollow tube

The internal reproductive organs of the female include the vagina, uterus, fallopian tubes and ovaries. The vagina is a hollow tube made up of muscles and extends from the opening to the uterus, running three to five inches long. The muscles in the vagina allow the vagina to expand and contract during intercourse and childbirth. The walls of the vagina are lined with mucous membrane to keep it moist and protected.

A thin sheet of tissue called the hymen, with one or two holes, partially covers the opening of the vagina. The hymen is different from one female to another. Most females may stretch or tear the hymen during their first sexual experience and the hymen may bleed slightly. However, some women who have had sex do not experience much change in their hymens.

Contractions

The vagina connects to the uterus or the womb at the neck of the womb or cervix which has thick, strong walls. The uterus which is only about three inches long and two inches wide, has thick lining and strong muscular walls that expand and contract to accommodate a growing foetus and to help push the baby out during delivery.

At the upper corners of the pear-shaped uterus are the fallopian tubes, about four inches long with a tiny passageway as wide as a piece of spaghetti. When the ovary releases an egg, it enters the fallopian tube and is propelled toward the uterus. The ovaries or gonads produce the female hormones, oestrogen and progesterone.

Hormones

When a baby girl is born, her ovaries contain hundreds of eggs which stay inactive until puberty. At puberty, the pituitary gland in the brain starts to produce hormones that stimulate the ovaries to produce female sex hormones, including oestrogen, which develops a girl into a sexually mature woman.

During puberty, girls begin their monthly period and release an egg as part of the menstrual cycle. Approximately once a month, during ovulation, an ovary sends a tiny egg into one of the fallopian tubes. If the egg is not fertilised by a sperm while in the fallopian tube, it dries up and leaves the body about two weeks later through the uterus with a flow of blood and tissues from the inner lining of the uterus. This is the menstrual flow which may last three to five days. A girl's first period is called menarche.

Chromosomes

When the sperm meets an ovum (egg), an embryo is formed and acquires chromosomes which will determine the sex of the child - XX for female and XY for male. After about six weeks of pregnancy, ovaries develop in females and testes develop in males. Abnormalities in development may be caused by genital defects or hormonal imbalances in the uterus. For example, if the female does not start producing oestrogen, there may be physical defects in the female like a vagina and no uterus.

An XX girl may be exposed to high levels of testosterone in the womb which could lead to the development of an enlarged clitoris or a small penis. If there is an extra X or Y chromosome, sexual differentiation may be difficult. Children may have genitalia 'in between' or resemble parts of either sex. If males do not start producing testosterone, abnormalities may result and they may not develop a penis and may resemble a girl even with the XY chromosome.

Abnormalities

Hormonal abnormalities may occur as a girl develops to womanhood. Dr Mark Hill, writing in UNSW Embryology, a publication of the University of New South Wales, describes human genital abnormalities as 'Disorders of Sex Development' (DSD) and includes chromosomal, gonadal dysfunction, tract abnormalities, external genitalia and gonadal descent. The previous human sex development terminology for abnormalities such as intersex, psuedohermaphroditism, hermaphrodites and sex reversal are outdated and stigmatising and should be classified as DSD.

If the physical features (such as facial hair, ripped muscles, masculine demeanour) of a female places doubt as to her sex, a sex test or gender verification test can be done to authenticate the sex. The question, why not just a physical, strip test to check the genitals? The answer is gender verification test is necessary because 'gender' goes beyond genitals with hormones playing a huge role in defining sex.

Sex tests

Sex hormones tests measure levels of the sex hormones, including oestrogen, progesterone and testosterone. Sex hormone tests are ordered to determine if secretion of these hormones is normal. Several different types of tests are used to evaluate the different sex hormones to help diagnose problems or disorders, and to monitor pregnancy.

To determine 'femaleness', testosterone levels are ordered to evaluate ambiguous sex characteristics which places doubt as to whether the person is female or male. Testosterone stimulates sperm production (spermatogenesis) and influences the development of male secondary sex characteristics.

Masculine features

Overproduction of testosterone in females, caused by ovarian and adrenal tumours, can result in masculinisation, the symptoms of which include cessation of the menstrual cycle known as amenorrhoea, imbalance of masculine features and excessive growth of body hair (hirsutism) (www.lifesteps.com).

Sex testing or gender verification is done on sportswomen who look like or perform as men. According to The Times, 'suspect athletes' will have their external appearance assessed by experts who will test their sex hormones, genes and chromosomes. According to DollyMix, all these tests sound pretty humiliating to say the least, but it does raise the question: how can it be so hard to tell? (www.dollymix.tv)