Testosterone is the principal male sex hormone, and it also plays an essential role in women’s overall health and wellness. http://www.vitalitmed.com/hormones/testosterone
This naturally occuring steroid hormone is found in mammals, reptiles, birds and other vertebrates. Home to the ‘Androgen Group’*, testosterone contributes to the growth of male sex organs and the development of sex characteristics.
*Androgens were first discovered in 1936 and are the precursor of all estrogens. Testosterone is the most well-known androgen hormone. However, Dihydrotestosterone (DHT and androstenedione are less known, but of equal importance in male development).
Testosterone’s Role In Development
Testosterone is essential in pre-birth development, puberty and continues to play a critical role in your overall health and welness throughout your entire life.
Let’s start at the beginning.
How Testosterone Affected You Before You Were Born
While your XX Chromosomes (if you’re female) or XY Chromosomes (if you’re male) formed in the womb, they determined your chromosomal sex. Your chromosomal sex determines gonadal sex, which is the sex that will be apparent as your sex organs develop and mature.
Men: The presence of your Y chromosome induced the formation of your testicles.
Two hormones most important to this process are testosterone and anti-Mullerian hormone (a hormone that suppresses the growth of female sex organs). Both of these essential hormones were produced by your testes.
Masculinization results from the ability of testosterone to induce male genitals and secondary male sex characteristics.
Women: The absence of your Y chromosome allowed you to follow your female developmental pathway. Interestingly, from a genetic standpoint, femaleness is the default setting, because no specific hormones are required for the formation of female genitalalia.
Your determined sex organs will secreted essential hormones during your early childhood development.
Specific Prenatal Androgen Effects At Two Developmental Stages:
1. Gestation (between 4-6 weeks):
Genital Virilization: Androgens; Dihydrotestosterone (DHT) and testosterone determined midline fusion, phallic urethra, scrotal layers and vaginal rugation.
Prostate and vesicular gland development
A surge in testosterone causes the male genitalia to develop and causes specific areas of the male brain to develop. An absence of testosterone causes the fetus to remain female (the default sex).
2. Second Trimester (Weeks 13-19):
Sexual Differentiation Of The Brain: This stage determines the feminization or masculinization of the baby. Interestingly, the mother’s testosterone levels during the second trimester are a better predictor of her daughter’s behavior than the daughter’s own adult testosterone levels. [Biology at Work: Rethinking Sexual Equality]