Flashcards in Physiology of Reproduction Deck (36)
What determines genetic sex?
Chromosomes. XX or XY
What determines gonadal sex?
Testes or Ovaries
What determines genital sex?
External genitalia which is influenced by hormones
What is SRY?
Sex determining region of the Y chromosome
What is ovary development dependent upon?
The presence of TWO X chromosomes
What happens with the loss of a single X chromosome as in Turner's syndrome?
Loss of one X chromosome results in ovarian dysgenesis but not loss of female ducts or genitalia
What occurs in meiosis I?
Chromosomes duplicate and exchange genetic material. Results in haploid numbers of duplicated chromosomes
What occurs in meiosis II?
Daughter cells have haploid (1N) chromosomes with the segregation of sex chromosomes providing a mechanism of sexual dimorphism.
What does sperm production require?
Is gonadal sex hormone dependent?
NO. It cannot be as the gonads make the hormones.
How is the decision for the progression to female genital structures made?
It occurs when there is no androgens present. Presence of androgens will influence male structure development.
What develops into seminiferous tubules, spermatogonia, sertoli cells, leydig cells?
What develops into secondary sex cords, oogonia, theca cells, granulosa cells?
What is the function of testosterone in regards to the ductal structures?
Keeps the Wolffian ducts
What is the function of AMH in regards to the ductal structures?
Degrades the Mullerian ducts
What happens if neither AMH nor testosterone are present?
The Mullerian ducts will remain and the Wolffian ducts will be lost resolution in a female.
What is the function of TDF?
It directs the development of the testes
What is the function of DHT?
It is more potent of an androgen than testosterone and it causes male genitalia development via androgen receptors.
What is the function of 5alpha-reductase?
Converts testosterone to DHT
What is the chromosome state of Turner's Syndrome?
What are the gonads/ducts/genitals found in Turner's syndrome?
No gonads (only streak)
External female genitals
What is male pseudohermaphroditism?
Testes are present with external female genitals
What is female pseudohermaphroditism?
Ovaries are present with external male genitals
What causes male pseudohermaphroditism?
What causes female pseudohermaphroditism?
What is the chromosome state found in androgen resistance?
What are the gonads/ducts/genitals found in androgen resistance (AKA testicular feminization)?
External female genitals
What is the chromosome state found in 5alpha-hydroxylase deficiency?
What are the gonads/ducts/genitals found in 5alpha-hydroxylase deficiency?
External can be male/female or both