Puberty Flashcards
(41 cards)
definition: adrenaarche
- what is it responsible for?
- when does it occur?
- regeneration of zona reticularis in the adrenal cortex
- responsible for secretion of sex steroid hormones
- occurs between age 6-8
definition: gonadarche
- what is it responsible for?
- when does it occur?
- pulsatile GnRH secretion from hypothalamus is increased
- stimulates anterior pituitary to secrete FSH and LH
- no phenotypic changes yet
- begins around age 8
definition: thelarche
- what is it responsible for?
- it occurs in response to what hormone?
- when does it occur?
- breast bud development
- first phenotypic sign of puberty
- occurs in response to estrogen
- occurs around age 11
definition: pubarche
- when does it occur?
- it is a result of what hormones?
- what phase does it follow?
- it precedes menarche by how long?
- occurs around age 12
- onset of pubic hair growth
- likely a result of increased androgens
- usually follow thelarche
- precedes menarche by 2 years
definition: menarche
- when does it occur?
- onset of menses
- average age 12-13 or 2.5 years after breast bud development
what happens to the HP axis during prepubertal years? why?
downregulation with reduction in GnRH pulses
what occurs with GnRH physiology at the onset of puberty?
- around 8 years of age GnRH becomes enhanced during sleep
- increased amplitude and frequency of pulsatile GnRH provoke progressively enhanced responses from pituitary of FSH and LH
- these continue to rise throughout puberty, but LH to a larger extent
how / where does estrogen produce both negative and positive feedback during puberty?
negative - combines within inhibin to inhibit FSH response
positive - increases LH secretory response to GnRH
the process of sexual maturation takes how long?
2.5 years
true precocious puberty is due to what cause? how does it develop?
GnRH dependent sex hormone production
develops secondary to early activation of the HPG axis
how does GnRH precocious purberty develop?
results from sex hormone production of androgens and estrogens independent of HP stimulation
McCune Albright syndrome is characterized by what signs?
- multiple bone fractures
- cafe au lait spots
- precocious puberty
what is the most common form of congenital adrenal hyperplasia? how does it present?
21 hydroxylase deficiency
presents with ambiguous genitalia
what is pathognomonic for late onset CAH?
elevated 17-OH progesterone
how does patients present with late onset CAH?
- premature adrenarche
- anovulation
- hyperandrogenism
what are the main goals of treatment for precocious puberty?
- arrest and diminish sexual maturation until a normal pubertal age and to maximize adult height
- GnRH agonists are used in GnRH dependent precocious puberty
- suppression of gonadal steroidogenesis is the treatment for GnRH independent PP
what is the treatment for precocious puberty?
GnRH agonists (ex leuprolide)
what is the most useful test in the evaluation of premature development?
bone age
what are the labs for precocious puberty?
- vaginal smear
- LH, FSH, estradiol, DHEA, TSH, 17-OHP
- CT or MRI of brain with contrast
- US for ovarian masses
early puberty puts girls at risk for what condition later in life?
breast cancer
when is puberty considered delayed for girls?
- when secondary sex characteristics have not appeared by age 13
- no evidence of menarche at 15-16
- or when menses have not begun 5 years after onset of thelarche
what is the most common cause of delayed puberty with an elevated FSH? which disease?
hypergonadotropic hypogonadism
turner syndrome (45 X,O)
what is the treatment for hypergonadotropic hypogonadism?
- GH early to normalize adult height
- estrogen initiated at normal time of puberty
progestins should not be given for hypergonadotropic hypogonadism until what tanner stage?
IV
