Internal Sex Organ Development:

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Internal Sex Organ Development Wolffian and
Mullerian Duct Differ.
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Wolffian Ducts

• Develop into Epididymis, Vas Deferens Seminal
  Vesicles
• Depend on testosterone for development
• In males T comes from Leydig cells in testis
• In females they regress due to lack of T

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Mullerian Ducts

• Develop into Fallopian tubes, uterus upper 1/3
  of vagina
• Develop in the absence of Anti-Mullerian Hormone
  (AMH)
• Males secrete AMH in Sertoli cells of testis
• Females dont secrete AMH, therefore Mullerian
  ducts develop

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External Genitalia Development

• Dihydrotestosterone (DHT) stimulates penis and
  scrotum development in male
• Clitoris, labia, outer 2/3 of vagina develop in
  the absence of any hormone in females

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DHT
From Carlson Fig 10.5
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Summary

• Formation of male requires the presence of one
  transcription factor and three hormones
• TDF (tscription factor from SRY gene)
• Anti-Mullerian Hormone
• Testosterone
• Dihydrotestosterone
• Formation of female occurs in absence of any of
  the above factors

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Congenital (Virilizing) Adrenal Hyperplasia

• Masculinization of female fetus in utero due to
  excess secretion of androgens.
• Female pseudohermaphrodite (ovaries normal but
  varying degrees of masculinization of genitalia)
• Typically caused by adrenal enzyme deficiency
  which causes high levels of weak androgens (e.g.,
  androstenedione)

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Congenital Adrenal Hypertrophy
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Androgen Insensitivity Syndrome

• Mutation in Androgen Hormone Receptor
• Testosterone produced but body cannot respond
• Testes present (abdominal)
• Neither male nor female internal sex organs
• Phenotypically (externally) female
• Short vagina ends in cul-de-sac
• Behaviorally Female

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Androgen Insensitivity Syndrome