"If a single or combination of these genes are mutated or deleted, downstream signalling is disrupted, leading to malformation of male external genitalia. SRY acts on gene SOX9 which drives Sertoli cell formation and testis differentiation. An absence in SRY causes SOX9 to not be expressed at the appropriate time or concentration, leading to a deficiency in testosterone and Anti-Müllerian hormone production. Inadequate levels of testosterone and Anti-Müllerian hormone disrupts the development of Wolffian ducts and internal genitalia that are key to male reproductive tract development. The lack of the male associated steroid hormones drives Müllerian duct development and perusal"
"the body and face, as well as sex hormone levels, are similar in preadolescent boys and girls. As puberty begins and sex hormone levels rise, differences appear, though some changes are similar in males and females. Male levels of testosterone directly induce the growth of the genitals, and indirectly (via dihydrotestosterone (DHT)) the prostate. Estradiol and other hormones cause breasts to develop in females. However, fetal or neonatal androgens may modulate later breast development by reducing the capacity of breast tissue to respond to later estrogen. In females, breasts are a manifestation of higher levels of estrogen; estrogen also widens"
"process is driven by androgen hormones, mainly testosterone and dihydrotestosterone (DHT). The newly formed testicles in the fetus are responsible for the secretion of androgens, that will cooperate in driving the sexual differentiation of the developing fetus, including its brain. This results in sexual differences between males and females. This fact has led some scientists to test in various ways the result of modifying androgen exposure levels in mammals during fetus and early life. Recent studies found an increased chance of homosexuality in men whose mothers previously carried to term many male children. This effect is nullified if the man"
"is secreted and converts the mesonephric ducts into male accessory structures, such as epididymis, vas deferens and seminal vesicle. Testosterone will also control the descending of the testes from the abdomen into the scrotom. Dihydrotestosterone, also known as (DHT) will differentiate the remaining male characteristics of the external genitalia. Further sex differentiation of the external genitalia occurs at puberty, when androgen levels again become disparate. Male levels of testosterone directly induce growth of the penis, and indirectly (via DHT) the prostate. Alfred Jost observed that while testosterone was required for mesonephric duct development, the regression of the paramesonephric duct was"
"from the counselor. Testosterone is a male sex hormone used in female to male gender reassignment. In women, the ovaries and adrenal glands produce testosterone naturally but at about one tenth the amount the typical male would produce. The hormone plays a role in the development of the sex drive, sperm production, fat distribution, red cell production and the maintenance of muscle mass and muscle strength. FTM transexxuals report an increase of sex drive because of the testosterone as Max goes into detail in his book The Testosterone Files The physical effects of HRT or Hormone Replacement Therapy using testosterone"
"Testosterone Testosterone is the primary male sex hormone and an anabolic steroid. In male humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair. In addition, testosterone is involved in health and well-being, and the prevention of osteoporosis. Insufficient levels of testosterone in men may lead to abnormalities including frailty and bone loss. Testosterone is a steroid from the androstane class containing a keto and hydroxyl groups at the three and seventeen"
"and a slower progression to completion, a direct result of the later rise and lower adult male levels of estradiol. The hormone that dominates female development is an estrogen called estradiol. While estradiol promotes growth of the breasts and uterus, it is also the principal hormone driving the pubertal growth spurt and epiphyseal maturation and closure. Estradiol levels rise earlier and reach higher levels in women than in men. The hormonal maturation of females is considerably more complicated than in boys. The main steroid hormones, testosterone, estradiol, and progesterone as well as prolactin play important physiological functions in puberty. Gonadal"
"(androgenetic alopecia), increase in chest hair, periareolar hair, perianal hair, leg hair, armpit hair. Testosterone is necessary for normal sperm development. It activates genes in Sertoli cells, which promote differentiation of spermatogonia. It regulates acute HPA (hypothalamic–pituitary–adrenal axis) response under dominance challenge. Androgen including testosterone enhances muscle growth. Testosterone also regulates the population of thromboxane A receptors on megakaryocytes and platelets and hence platelet aggregation in humans. Adult testosterone effects are more clearly demonstrable in males than in females, but are likely important to both sexes. Some of these effects may decline as testosterone levels might decrease in the later"
"development of female secondary sexual characteristics, such as breasts, and are also involved in the thickening of the endometrium and other aspects of regulating the menstrual cycle. In males, estrogen regulates certain functions of the reproductive system important to the maturation of sperm<ref name=""titleScience News Online (12/6/97): Estrogens Emerging Manly Alter Ego""></ref> and may be necessary for a healthy libido. Estrogens are responsible for the development of female secondary sexual characteristics during puberty, including breast development, widening of the hips, and female fat distribution. Conversely, androgens are responsible for pubic and body hair growth, as well as acne and axillary"
"sex characteristics. The main male hormone is testosterone, which is produced mainly by the testicles. It is dihydrotestosterone (DHT), a metabolite of testosterone, that predominantly regulates the prostate. About 20,000 protein coding genes are expressed in human cells and almost 75% of these genes are expressed in the normal prostate. About 150 of these genes are more specifically expressed in the prostate with about 20 genes being highly prostate specific. The corresponding specific proteins are expressed in the glandular and secretory cells of the prostatic gland and have functions that are important for the characteristics of semen. Examples of some"
"are directed by reproductive hormones of the hypothalamic-pituitary-gonadal axis (HPG axis). Receptors for reproductive hormones (such as estrogens, progestogens, androgens and gonadotropins) have been found to be present in all tissues of the body. Thus, HPG axis hormones normally promote growth and development of the organism early in life in order to achieve reproduction. Hormones levels then begin to change in men around age 30 and more abruptly in women when they reach menopause, around age 50. When the HPG axis becomes unbalanced, cellular growth and development is dysregulated, and cell death and dysfunction can occur, both of which can"
"in the FSH receptor and mutations in steroidogenic acute regulatory protein (StAR protein) which regulates steroid hormone production. 46,XY gonadal dysgenesis is characteristic of male hypogonadism with karyotype 46,XY. In embryogenesis, the development of the male gonads is controlled by the testis determining factor located on the sex-determining region of the Y chromosome (SRY). The male gonad is dependent on SRY and the signalling pathways initiated to several other genes to facilitate testis development. The aetiology of 46,XY gonadal dysgenesis can be caused by mutations in the genes involved in testis development such as SRY, SOX9, WT1, SF1, and DHH."
"the impact of these factors is difficult. Evidence suggests that neonatal androgens, male sex hormones produced in the womb during gestation, play an important role. Testosterone in the womb directly codes the brain for either male or female-typical development. This includes both the physical structure of the brain and the characteristics the person expresses because of it. Persons exposed to high levels of testosterone during gestation typically develop a male gender identity while those who are not or those who do not possess the receptors necessary to interact with these hormones typically develop a female gender identity. An individual's genes"
"The larger relative size of the male amygdala may be attributed to this extended developmental period. In addition to longer periods of development, other neurological and hormonal factors may contribute to sex-specific developmental differences. The amygdala is rich in androgen receptors – nuclear receptors that bind to testosterone. Androgen receptors play a role in the DNA binding that regulates gene expression. Though testosterone is present within the female hormonal systems, women have lower levels of testosterone than men. The abundance of testosterone in the male hormonal system may contribute to development. In addition, the grey matter volume on the amygdala"
"testosterone and Anti-Müllerian hormone for the embryo's development into a male. This differentiation begins about eight or nine weeks after conception. Some sources state that it continues until the twelfth week, while others state that it is clearly evident by the thirteenth week and that the sex organs are fully developed by the sixteenth week. The clitoris develops from a phallic outgrowth in the embryo called the genital tubercle. Initially undifferentiated, the tubercle develops into either a clitoris or penis during development of the reproductive system depending on exposure to androgens (primarily male hormones). The clitoris forms from the same"
"for mating. Biosynthesis of the sex pheromone is controlled by a neurohormone called Pheromone Biosynthesis Activating Neuropeptide (PBAN). This 33-amino-acid-long peptide is present in both sexes in the brain-suboesophageal ganglions (Br-SOG) during both scotophase and photophase. It has been shown that the Juvenile Hormone is involved in the release of PBAN in both males and females. PBAN aids in pheromone production in females and pheromone responsiveness in males. In another species, PBAN release has been shown to be stimulated by external factors including photoperiod, temperature and odorants from host-plants The Juvenile Hormone (JH), released by the corpora allata (CA), is"
"cells begin to produce androgen hormones. The androgen hormone dihydrotestosterone is responsible for the development of the male external genitalia. The testicles descend during prenatal development in a two-stage process that begins at eight weeks of gestation and continues through the middle of the third trimester. During the transabdominal stage (8 to 15 weeks of gestation), the gubernacular ligament contracts and begins to thicken. The craniosuspensory ligament begins to break down. This stage is regulated by the secretion of insulin-like 3 (INSL3), a relaxin-like factor produced by the testicles, and the INSL3 G-coupled receptor, LGR8. During the transinguinal phase (25"
"The male generative glands also contain Sertoli cells, which require testosterone for spermatogenesis. Like most hormones, testosterone is supplied to target tissues in the blood where much of it is transported bound to a specific plasma protein, sex hormone-binding globulin (SHBG). In males, testosterone is synthesized primarily in Leydig cells. The number of Leydig cells in turn is regulated by luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In addition, the amount of testosterone produced by existing Leydig cells is under the control of LH, which regulates the expression of 17β-hydroxysteroid dehydrogenase. The amount of testosterone synthesized is regulated by the"
"be some innate mechanism that differs between the sexes. This innate mechanism is evolutionary in the sense that the hormones for females are concurrently passed down to other females, and the same with males. Other than external genitals, there are few physical differences before puberty. Small differences in height and start of physical maturity are seen. In the first decade of human life there is a significant amount of overlap between children of both sexes. The gradual growth in sex difference throughout a person's life is a product of various hormones. Testosterone is the major active hormone in male development"
"a chain reaction to occur. The male and female gonads are subsequently activated, which puts them into a state of rapid growth and development; the triggered gonads now commence the mass production of the necessary chemicals. The testes primarily release testosterone, and the ovaries predominantly dispense estrogen. The production of these hormones increases gradually until sexual maturation is met. Some boys may develop gynecomastia due to an imbalance of sex hormones, tissue responsiveness or obesity. Facial hair in males normally appears in a specific order during puberty: The first facial hair to appear tends to grow at the corners of"
"steroid in the process of spermatogenesis and is regulated by a hormone known as luteinizing hormone. FSH plays a role in the spermatogenic capacity of the adult male as it controls the proliferation of Sertoli cells during either the perinatal or pubertal period, or both. However, testosterone has been found to be the most important hormone that is responsible for both the initiation and the maintenance of spermatogenesis. It is known that spermatogenesis is under the control of androgens, but germ cells (that will become gametes), do not express a functional androgen receptor, which are activated by the binding of"
"the steroid hormones, estrogen and progesterone, growth hormone (GH), mostly via its secretory product, insulin-like growth factor 1 (IGF-1), and prolactin. These regulators induce the expression of growth factors, such as amphiregulin, epidermal growth factor (EGF), IGF-1, and fibroblast growth factor (FGF), which in turn have specific roles in breast growth and maturation. At puberty, gonadotropin-releasing hormone (GnRH) begins to be secreted, in a pulsatile manner, from the hypothalamus. GnRH, in turn, induces the secretion of the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), from the pituitary gland. These hormones travel to the ovaries through the bloodstream and cause"
"the Leydig cells of the testes to make testosterone and blood levels begin to rise. For much of puberty, nighttime levels of testosterone are higher than daytime. Regularity of frequency and amplitude of gonadotropin pulses seems to be less necessary for progression of male than female puberty. However, a significant portion of testosterone in adolescent boys is converted to estradiol. Estradiol mediates the growth spurt, bone maturation, and epiphyseal closure in boys just as in girls. Estradiol also induces at least modest development of breast tissue (gynecomastia) in a large proportion of boys. Boys who develop mild gynecomastia or even"
"by gonadotropin-releasing hormone produced in the hypothalamus. Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of gonadal ridges, and only later are differentiated to male or female sex organs. The presence of the SRY gene, located on the Y chromosome and encoding the testis determining factor, determines male sexual differentiation. In the absence of the SRY gene from the Y chromosome, the female sex (ovaries instead of testes) will develop. The development of the gonads is a part of the development of the urinary and reproductive organs. Gonad A gonad,"
"leads to the secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) produced by the anterior pituitary gland (Figure 4). The release of FSH into the testes will enhance spermatogenesis and lead to the development of sertoli cells, which act as nursing cells where spermatids will go to mature after Meiosis II. LH promotes leydig cell secretion of testosterone into the testes and blood, which induce spermatogenesis and aid the formation of secondary sex characteristics. From this point on, the secretion of FSH and LH (inducing production of testosterone) will stimulate spermatogenesis until the male dies. Increasing the hormones FSH"
"such as testosterone, androstenedione and dihydrotestosterone are required for the development of organs in the male reproductive system, including the seminal vesicles, epididymis, vas deferens, penis and prostate. AAS are testosterone derivatives designed to maximize the anabolic effects of testosterone. AAS are consumed by elite athletes competing in sports like weightlifting, bodybuilding, and track and field. Male recreational athletes take AAS to achieve an “enhanced” physical appearance. AAS consumption disrupts the hypothalamic–pituitary–gonadal axis (HPG axis) in males. In the HPG axis, gonadotropin-releasing hormone (GnRH) is secreted from the arcuate nucleus of the hypothalamus and stimulates the anterior pituitary to secrete"
"are differentiated first, and then the brain is sexually differentiated ""under the influence, mainly, of sex hormones such as testosterone, estrogen and progesterone on the developing brain cells and under the presence of different genes as well ... . The changes brought about in this stage are permanent. ... [S]exual differentiation of the brain is not caused by hormones alone, even though they are very important for gender identity and sexual orientation."" Fetal gonads develop primarily based on the presence or absence of androgen hormones, mainly testosterone, dihydrotestosterone (DHT) and androstenedione; production of testosterone and conversion into dihydrotestosterone during weeks"
"as a medication, see the androstanolone article. DHT is biologically important for sexual differentiation of the male genitalia during embryogenesis, maturation of the penis and scrotum at puberty, growth of facial, body, and pubic hair, and development and maintenance of the prostate gland and seminal vesicles. It is produced from the less potent testosterone by the enzyme 5α-reductase in select tissues, and is the primary androgen in the genitals, prostate gland, seminal vesicles, skin, and hair follicles. DHT signals mainly in an intracrine and paracrine manner in the tissues in which it is produced, playing only a minor role, if"
"the gonads for the development and maintenance of proper adult reproductive physiology. LH acts on Leydig cells in the male testes and theca cells in the female. FSH acts on Sertoli cells in the male and follicular cells in the female. Combined this causes the secretion of gonadal sex steroids and the initiation of folliculogenesis and spermatogenesis. The production of sex steroids forms a negative feedback loop acting on both the anterior pituitary and hypothalamus causing a pulsatile secretion of GnRH. GnRH neurons lack sex steroid receptors and mediators such as kisspeptin stimulate GnRH neurons for pulsatile secretion of GnRH."
"differentiation of penis, scrotum and prostate. In adulthood, DHT contributes to balding, prostate growth, and sebaceous gland activity. Although androgens are commonly thought of only as male sex hormones, females also have them, but at lower levels: they function in libido and sexual arousal. Also, androgens are the precursors to estrogens in both men and women. In addition to their role as natural hormones, androgens are used as medications; for information on androgens as medications, see the androgen replacement therapy and anabolic steroid articles. The main subset of androgens, known as adrenal androgens, is composed of 19-carbon steroids synthesized in"
"an Adam's apple. An important sexual hormone of males is androgen, and particularly testosterone. The testes release a hormone that controls the development of sperm. This hormone is also responsible for the development of physical characteristics in men such as facial hair and a deep voice. The human female reproductive system is a series of organs primarily located inside the body and around the pelvic region of a female that contribute towards the reproductive process. The human female reproductive system contains three main parts: the vulva, which leads to the vagina, the vaginal opening, to the uterus; the uterus, which"
"which prevents the embryonic Müllerian ducts from developing into fallopian tubes and other female reproductive tract tissues in male embryos. MIH and androgens cooperate to allow for movement of testes into the scrotum. Before the production of the pituitary hormone luteinizing hormone (LH) by the embryo starting at about weeks 11–12, human chorionic gonadotrophin (hCG) promotes the differentiation of Leydig cells and their production of androgens at week 8. Androgen action in target tissues often involves conversion of testosterone to 5α-dihydrotestosterone (DHT). At the time of puberty, androgen levels increase dramatically in males, and androgens mediate the development of masculine"
"a female. The part of the Y-chromosome which is responsible for maleness is the sex-determining region of the Y-chromosome, the SRY. The SRY activates Sox9, which forms feedforward loops with FGF9 and PGD2 in the gonads, allowing the levels of these genes to stay high enough in order to cause male development; for example, Fgf9 is responsible for development of the spermatic cords and the multiplication of Sertoli cells, both of which are crucial to male sexual development. The ZW sex-determination system, where males have a ZZ (as opposed to ZW) sex chromosome may be found in birds and some"