development Flashcards
how does PRL affect ovulation
low FSH/LH, no LH surge, low E2, low AVPV stimulation, no ovulation
how does PRL affect gonadotropins
reduces responsiveness of LH and FSH
is PRL a reliable source of contraception
yes
what is the milk ejection reflex
suckling from infant causes oxytocin release from posterior pituitary
how does oxytocin contribute to lactation
-oxytocin causes contraction of smooth muscles of myoepithelial cells
-squeezing alveoli forces milk out of nipple
-conditioning can lead to oxytocin release upon seeing/smelling/hearing baby
what are the internal reproductive structures of a male
epididymis, vas deferens, seminal vesicles
what are the internal reproductive structures of a female
oviduct, uterus, cervix
what are the external reproductive structures of a male
penis, scrotum
what are the external reproductive structures of a female
vagina, clitoris, labia
what is the SRY gene
-sex determining region of Y
-testis-determining factor
what is the pseudo-autosomal region involved in
-bone formation => height
how can an XX person have testicles
-translocation of Y chromosome to X chromosome
what is the DAX-1 gene
dose-sensitive repressor gene (repressing SRY)
what is X-inactivation
-when there are two X chromosomes, one X chromosome gets “shut down” in each cell
-event is random
-results in formation of Barr bodies
are pseudo-autosomal regions always transcribed
yes
what are the characteristics for klinefelter syndrome
-XXY genotype (or XXXY, XXXXY)
-some dose-dependent gene in the pseudo-autosomal region of X chromosome
eg: DAX-1
-DAX-1 leads to hypogonadism
-altered fertility
-leads to increased height (SHOX)
how does klinefelter syndrome occur
-during puberty, rise in gonadotropins do not cause normal growth of Leydig or Sertoli cells
-Leydig cells become abnormal: decreased testosterone and increased gonadotropins
-increased estrogen:androgen ratio
how does XO genotype (turner syndrome) affect follicular development
ovaries don’t form correctly with only 1 X chromosome so no follicular development
how does XO genotype (turner syndrome) affect estradiol production
no granulosa cells, no E2
how does XO genotype (turner syndrome) affect secondary sex characteristics
none because they come from E2
how does XO genotype (turner syndrome) affect height
decreased height
