Early in fetal life, germ cells migrate to the genital ridge. By week 6, undifferentiated gonads consist of germ cells, supporting cells, and steroidogenic cells. In a male, SRY and other genes induce differentiation of supporting cells into Sertoli cells and (indirectly) steroidogenic cells into Leydig cells to form testes, which become microscopically identifiable and begin to produce hormones by week 8. Germ cells become spermatogonia. Without SRY, ovaries form during months 2-6. Failure of ovarian development ...

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Sexual differentiation, Sexual differentiation - Chromosomal sex differences, Sexual differentiation - Gonadal differentiation, Sexual differentiation - Hormonal differentiation, Sexual differentiation - Internal genital differentiation, Sexual differentiation - External genital differentiation, Sexual differentiation - Breast differentiation, Sexual differentiation - Other body differentiation, Sexual differentiation - Brain differentiation, Sexual differentiation - Psychological and behavioral differentiation, Sexual differentiation - Psychological and behavioral differentiation in humans, Sexual differentiation - Gender identity role and orientation, Sexual differentiation - Defeminization and masculinization female as the default path

Read more here: » Sexual differentiation: Encyclopedia II - Sexual differentiation - Gonadal differentiation

See also:

Sexual differentiation, Sexual differentiation - Chromosomal sex differences, Sexual differentiation - Gonadal differentiation, Sexual differentiation - Hormonal differentiation, Sexual differentiation - Internal genital differentiation, Sexual differentiation - External genital differentiation, Sexual differentiation - Breast differentiation, Sexual differentiation - Other body differentiation, Sexual differentiation - Brain differentiation, Sexual differentiation - Psychological and behavioral differentiation, Sexual differentiation - Psychological and behavioral differentiation in humans, Sexual differentiation - Gender identity role and orientation, Sexual differentiation - Defeminization and masculinization female as the default path

Read more here: » Sexual differentiation: Encyclopedia II - Sexual differentiation - Hormonal differentiation

Gonads are histologically distinguishable by 6-8 weeks of gestation. A fetus of that age has both mesonephric (wolffian) and paramesonephric (mullerian) ducts. Subsequent development of one set and degeneration of the other depends on the presence or absence of two testicular hormones: testosterone and AMH. Disruption of typical development may result in the development of both, or neither, duct system, which may produce morpologically bisexual individuals. Local testosterone causes each wolffian duct to develop into epididymis, vas d ...

See also:

Sexual differentiation, Sexual differentiation - Chromosomal sex differences, Sexual differentiation - Gonadal differentiation, Sexual differentiation - Hormonal differentiation, Sexual differentiation - Internal genital differentiation, Sexual differentiation - External genital differentiation, Sexual differentiation - Breast differentiation, Sexual differentiation - Other body differentiation, Sexual differentiation - Brain differentiation, Sexual differentiation - Psychological and behavioral differentiation, Sexual differentiation - Psychological and behavioral differentiation in humans, Sexual differentiation - Gender identity role and orientation, Sexual differentiation - Defeminization and masculinization female as the default path

Read more here: » Sexual differentiation: Encyclopedia II - Sexual differentiation - Internal genital differentiation

In biology and medicine, virilization refers to the development of changes which make a male body different from a female body. Most of the changes of virilization are produced by androgens. Virilization is most commonly used in three medical contexts: prenatal sexual differentiation, the postnatal changes of normal male puberty, and excessive androgen effects in girls or women. Virilization - Prenatal virilization. In the prenatal period, virilization refers to closure of the perineum, thinning and rugatio ...

Including:

• Virilization - Prenatal virilization
• Virilization - Normal virilization
• Virilization - Abnormal childhood virilization
• Virilization - Abnormal virilization in adolescent or adult women

Read more here: » Virilization: Encyclopedia - Virilization

The XY sex-determination system is a well-known sex-determination system. It is found in human beings and other mammals. In the XY sex-determination system, females have two of the same kind of sex chromosome (XX), while males have two distinct sex chromosomes (XY). Some species (including humans) have a gene SRY on the Y chromosome that determines maleness; others (such as the fruit f ...

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The Wolffian duct (also known as archinephric duct, Leydig's duct, and the mesonephric duct) is a paired organ found in mammals including humans during embryogenesis. It connects the primitive kidney Wolffian body (or mesonephros) to the cloaca and serves as the anlage for certain male reproductive organs. In a male, it develops into a system of connected organs between the testis and the prostate, namely the rete testis, the efferent ducts, the epididymis, the vas deferens, the seminal vesicle, and ...

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Sex, in the scope of this article and category, refers to the male and female duality of biology and reproduction. The somewhat similar term gender has more to do with identity than biology. The concept is confined to organisms that reproduce sexually. The female sex is defined as the one which produces the larger gamete (i.e., reproductive cell) and which typically bears the offspring. The category of sex reflects the biological reproductive function, rather than sexaulity or other behaviors. In some lower animals, sex may be assigned to specific structures rather than the entire organism as some species, such a ...

Including:

• Sex - Sex in non-animal species
• Sex - Sex among humans
• Sex - Discordance
• Sex - Biological varieties of discordance
• Sex - Psychological behavioral and cultural varieties of discordance
• Sex - Social and legal considerations

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Androgen insensitivity syndrome (AIS, or "Androgen resistance syndrome") is a set of disorders of sexual differentiation that results from mutations of the gene encoding the androgen receptor. It has also been called androgen resistance in the medical literature. The nature of the resulting problem varies according to the structure and sensitivity of the abnormal receptor. Most of the forms of AIS involve variable degrees of undervirilization and/or infertility in XY persons of either sex. A woman with complete androgen ...

Including:

• Androgen insensitivity syndrome - Genetics inheritance and incidence
• Androgen insensitivity syndrome - Normal function of androgens and the androgen receptor
• Androgen insensitivity syndrome - Prenatal effects of testosterone in 46XY fetus
• Androgen insensitivity syndrome - Early postnatal effects of testosterone in 46XY infants
• Androgen insensitivity syndrome - Pubertal effects of testosterone in 46XY children
• Androgen insensitivity syndrome - Problems produced by androgen insensitivity
• Androgen insensitivity syndrome - 1. Complete AIS
• Androgen insensitivity syndrome - 2. Incomplete or partial AIS
• Androgen insensitivity syndrome - 3. Reifenstein syndrome
• Androgen insensitivity syndrome - 4. Infertile male syndrome
• Androgen insensitivity syndrome - 5. Undervirilized fertile male syndrome
• Androgen insensitivity syndrome - 6. X-linked spinal and bulbar atrophy syndrome

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Erotica, from the Greek language Eros ("love"), are works of art, including literature, photography, film, sculpture and painting, that deal substantively with erotically stimulating or arousing descriptions. Erotica is rather a modern word used to describe the portrayal of human sensuality and sexuality with high-art aspirations, differentiating such work from commercial pornography. Erotica geared towards homo ...

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A beard is the hair that grows on a man's chin, cheeks, neck, and the area above the upper lip (the opposite is a clean-shaven face). When differentiating between upper and lower facial hair, a beard specifically refers to the facial hair on the lower part of a man's chin (excluding the moustache, which refers to hair on the upper lip). In the course of history, men with facial hair have been ascribed various attributes such as wisdom, sexual potency, or high status, but also a lack of cleanliness and refinement, or an eccentri ...

Including:

• Beard - History
• Beard - The Ancient and Classical world
• Beard - From the Renaissance to the present day
• Beard - Modern attitudes in America
• Beard - Beards in Religion
• Beard - Early Christian attitudes
• Beard - Modern prohibition of beards
• Beard - Sport
• Beard - The Armed Forces
• Beard - Sayings about beards
• Beard - Beard styles
• Beard - Reference

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For illustrations, see the External links section. By 7 weeks, a fetus has a genital tubercle, urogenital groove and sinus, and labioscrotal folds. In females, without excess androgens, these become the clitoris, urethra and vagina, and labia. Males become externally distinct between 8 and 12 weeks, as androgens enlarge the phallus and cause the urogenital groove and sinus to fuse in the midline, producing a ...

See also:

Sexual differentiation, Sexual differentiation - Chromosomal sex differences, Sexual differentiation - Gonadal differentiation, Sexual differentiation - Hormonal differentiation, Sexual differentiation - Internal genital differentiation, Sexual differentiation - External genital differentiation, Sexual differentiation - Breast differentiation, Sexual differentiation - Other body differentiation, Sexual differentiation - Brain differentiation, Sexual differentiation - Psychological and behavioral differentiation, Sexual differentiation - Psychological and behavioral differentiation in humans, Sexual differentiation - Gender identity role and orientation, Sexual differentiation - Defeminization and masculinization female as the default path

Read more here: » Sexual differentiation: Encyclopedia II - Sexual differentiation - External genital differentiation

General habitus and shape of body and face, as well as sex hormone levels, are similar in prepubertal boys and girls. As puberty progresses and sex hormone levels rise, obvious differences appear. In males, testosterone directly increases size and mass of muscles, vocal cords, and bones, enhancing strength, deepening the voice, and changing the shape of the face and skeleton. Converted into DHT in the skin, it accelerates growth of androgen-responsive facial and body hair. Taller statu ...

See also:

Sexual differentiation, Sexual differentiation - Chromosomal sex differences, Sexual differentiation - Gonadal differentiation, Sexual differentiation - Hormonal differentiation, Sexual differentiation - Internal genital differentiation, Sexual differentiation - External genital differentiation, Sexual differentiation - Breast differentiation, Sexual differentiation - Other body differentiation, Sexual differentiation - Brain differentiation, Sexual differentiation - Psychological and behavioral differentiation, Sexual differentiation - Psychological and behavioral differentiation in humans, Sexual differentiation - Gender identity role and orientation, Sexual differentiation - Defeminization and masculinization female as the default path

Read more here: » Sexual differentiation: Encyclopedia II - Sexual differentiation - Other body differentiation

Humans have 46 chromosomes, including 2 sex chromosomes, XX in females and XY in males. It is obvious that the Y chromosome must carry at least one essential gene which determines testicular formation (originally termed TDF). A gene in the sex-determining region of the short arm of the Y, now referred to as SRY, has been found to direct production of a protein which binds to DNA, inducing differentiation of cells derived from the genital ridges into testes. In transgenic XX mice (and some human XX ...

See also:

Sexual differentiation, Sexual differentiation - Chromosomal sex differences, Sexual differentiation - Gonadal differentiation, Sexual differentiation - Hormonal differentiation, Sexual differentiation - Internal genital differentiation, Sexual differentiation - External genital differentiation, Sexual differentiation - Breast differentiation, Sexual differentiation - Other body differentiation, Sexual differentiation - Brain differentiation, Sexual differentiation - Psychological and behavioral differentiation, Sexual differentiation - Psychological and behavioral differentiation in humans, Sexual differentiation - Gender identity role and orientation, Sexual differentiation - Defeminization and masculinization female as the default path

Read more here: » Sexual differentiation: Encyclopedia II - Sexual differentiation - Chromosomal sex differences

Human adults and children show many psychological and behavioral sex differences, both dichotomous and dimorphic. Some (e.g., dress) are learned and obviously cultural. Others (e.g., early verbal fluency, spatial reasoning) are demonstrable across cultures and may have both biological and learned determinants. Because we cannot explore hormonal influences on human reproductive behavior experimentally, and because potential political implications are so unwelcome to many factions of society, the relative contributions of biological factors an ...

See also:

Sexual differentiation, Sexual differentiation - Chromosomal sex differences, Sexual differentiation - Gonadal differentiation, Sexual differentiation - Hormonal differentiation, Sexual differentiation - Internal genital differentiation, Sexual differentiation - External genital differentiation, Sexual differentiation - Breast differentiation, Sexual differentiation - Other body differentiation, Sexual differentiation - Brain differentiation, Sexual differentiation - Psychological and behavioral differentiation, Sexual differentiation - Psychological and behavioral differentiation in humans, Sexual differentiation - Gender identity role and orientation, Sexual differentiation - Defeminization and masculinization female as the default path

Read more here: » Sexual differentiation: Encyclopedia II - Sexual differentiation - Psychological and behavioral differentiation in humans

Sexual differentiation in mammals is biased towards developing as a female, so that it is often said that female is the default developmental pathway. Two processes: defeminization, and masculinization, are involved in producing male typical morphology and behavior. Disruption of either of these processes in males produces female-typical development. The opposite is not true, disruption of normal sexual development in females does not lead to male-typical endpoints. Defeminization involves the suppression of the development of female ...

See also:

Sexual differentiation, Sexual differentiation - Chromosomal sex differences, Sexual differentiation - Gonadal differentiation, Sexual differentiation - Hormonal differentiation, Sexual differentiation - Internal genital differentiation, Sexual differentiation - External genital differentiation, Sexual differentiation - Breast differentiation, Sexual differentiation - Other body differentiation, Sexual differentiation - Brain differentiation, Sexual differentiation - Psychological and behavioral differentiation, Sexual differentiation - Psychological and behavioral differentiation in humans, Sexual differentiation - Gender identity role and orientation, Sexual differentiation - Defeminization and masculinization female as the default path

Read more here: » Sexual differentiation: Encyclopedia II - Sexual differentiation - Defeminization and masculinization female as the default path

Study suggests that distinct tendencies differentiate male and female sexual fantasies. These traits are hardly universal; just because a person happens to be male does not indicate he will have only "male" fantasies that night, let alone for the whole of his life. In general, however, male sexual fantasies tend to be shorter and imagistic, where female sexual fantasies tend to be longer and have more narrative, as well as a greater focus on the relationships between the characters in the fantasy. The essence of a "male" fantasy might be cap ...

See also:

Sexual fantasy, Sexual fantasy - Gender differentiation

Read more here: » Sexual fantasy: Encyclopedia II - Sexual fantasy - Gender differentiation

In the prenatal period, virilization refers to closure of the perineum, thinning and rugation of the scrotum, growth of the phallus, and closure of the urethral groove to the tip of the penis. In this context masculinization is synonymous with virilization. Prenatal virilization of genetic females and undervirilization of genetic males are common causes of ambiguous genitalia and intersex conditions. Undervirilization can occur if a genetic male cannot produce enough androgen or the body tissues cannot respond to it. Ext ...

See also:

Virilization, Virilization - Prenatal virilization, Virilization - Normal virilization, Virilization - Abnormal childhood virilization, Virilization - Abnormal virilization in adolescent or adult women

Read more here: » Virilization: Encyclopedia II - Virilization - Prenatal virilization

PMDS type I results from mutations of the gene (AMH) for AMH on chromosome 19p3.3. OMIM 600957 PMDS type II results from mutations of the gene (AMH-RII) for the AMH receptor on 12q13. OMIM 600956 Both types of disorders are inherited as autosomal recessive conditions with expression limited to males (as females with AMH deficiency have no identified problems). ...

See also:

Persistent müllerian duct syndrome, Persistent müllerian duct syndrome - Molecular genetics and inheritance

Read more here: » Persistent müllerian duct syndrome: Encyclopedia II - Persistent müllerian duct syndrome - Molecular genetics and inheritance

Intersex is a broadly defined term that usually denotes the presence of discordance of the biological aspects of sex: at least some aspect of the genitalia, internal organs, gonadal tissue, or chromosomes is more typical of the other sex, or incompletely differentiated. When the external genitalia appear to be "in between", they are described as ambiguous. In approximately 1 in 5,000 infants there is enough variation in the appearance of the external genitalia to give rise to hesitation about appropriate assignment by the physician in ...

See also:

Sex assignment, Sex assignment - Assignment in intersex conditions, Sex assignment - Re-assignment of sex or gender

Read more here: » Sex assignment: Encyclopedia II - Sex assignment - Assignment in intersex conditions

Estradiol, like other sex steroids, is derived from cholesterol. After side chain cleavage and either utilizing the delta-5 pathway or the delta-4 pathway androstenedione is the key intermediary. Androstendione is either converted to testosterone which in turn undergoes aromatization to estradiol, or, alternatively, androstendione is aromatized to estrone which is converted to estradiol. Co ...

See also:

Estradiol, Estradiol - Synthesis, Estradiol - Production, Estradiol - Mechanism of action, Estradiol - Effects, Estradiol - Role in sexual differentiation, Estradiol - Therapy, Estradiol - Hormone replacement therapy, Estradiol - Blocking estrogens

Read more here: » Estradiol: Encyclopedia II - Estradiol - Synthesis