Male Reproductive Endocrinology - IN Flashcards
what does the SRY gene encode
TDF = testis determining factor
what factors determine phenotypic males
development of accessory sex organs, external genitalia that require DHT, and secondary sex characteristics
what cells produce androgens
Leydig cells
what do androgens promote
differentiation of wollfian duct to vas deferens, seminal vesicels, ejaculatory duct
differentiation of mesonephros to the epididymis
prostate development
what happens to mullerian ducts
they degenerate in response to anti-mullerian hormone from sertoli cells
what does DHT accomplish
stimulates formation of male external genitalia from undifferentiated structure
what happens to GnRH at pooberty?
frequency and amplitude of pulses increases and the sensitivity of the hypothalamus/pituitary to testosterone decreases, testosterone increases, spermatogenesis begins
what is the progression of spermatogenesis
1ary spermatocyte -> 2dary spermatocyte -> spermatid -> spermatozoa
what happens when FSH binds to sertoli cells
increased transcription of androgen binding protein, p450 aromatase, and inhibins
why does LH bind to leydig cells
to stimulate testosterone
what compounds regulate the pattern of androgens
E2, T, DHT
what happens to your balls when you take steroids
High peripheral T causes LH levels to drop, and thus testes are no longer making T, and it’s not able to be bound to the ABPs to keep them in high concentrations in the testes…-> Shrinkage.
what causes male pseudohermaphroditism
any deficit in androgens
5-a-reductase deficiency
androgen insensitivity syndrome
what are androgenic actions
Maturation of sex organs, development of secondary sexual characteristics (voice deepening/hair)
what are anabolic actions
Promoting protein synthesis, muscle growth/inc in strength, increase in bone density/strength (the maturation occurs more slowly in men since it’s mediated by estradiols; this is another reason girls go through their growth spurts first).
