Puberty- Teresa Flashcards
What are underlying endocrinology of puberty?
Increase in activity of adrenal gland- steroidogenesis
Increase pulsatile GnRH–>increase LH/FSH release–>increase circulating estrogen (females) and testosterone (males)
Mitosis of 1’ spermatogonia
Correlated onset of gamete maturation
What causes start of puberty?
Discontinuation of suppression of HPG
Phenotypic changes of puberty?
axial growth
growth of 2’ sex organs
gender specific and nongender specific hair growth
central processing alterations d/t pathway remodeling (impaired judgement)
vocal cord thickening
menarche
libido increase
Adrenarche:
Pubarche (pubic hair growth)
Thelarche
breast development
gonadarche
production of ovarian hormones and mature gametes
menarche
uterine responses to ovarian hormones
Age definition of precocious puberty?
<8 for girls
<9 for males
Types of precocious puberty?
GDPP: gonadotropin dependent precocious puberty
GIPP: gonadotropin independent precocious puberty
What defines GDPP?
Events that would remove inhibition on the HPG axis:
early activation of pulsatile activity of gonadotropic axis so that all puberty signs are stage matched but occur earlier than expected
What defines GIPP?
Events that provide peripheral hormones to carry out puberty
Staging is not matched
Causes of GDPP??
idiopathic (80%)
central causes: hypothalamic hamartomas, CNS tumors, cranial irradiation, hydrocephalus, and trauma
Causes of GIPP?
Girls: ovarian cysts, ovarian tumors
Boys: leydig cell tumors, HCG secreting germ cell tumors
Both sexes: exogenous estrogen, adrenal pathology with excess androgen, pituitary hormones
In GIPP what are causes of adrenarche?
Tumors of adrenal gland
congenital adrenal hyperplasia (CAH, 21 hydroxylase deficiency)
What are causes of bone age older than chronological age along with adrenarche in boys and thelarche in girls (GIPP)?
HCG secreting tumors
gonadal tumors
Why are kids with precocious puberty shorter?
Prepubertal bone plates are very sensitive to estradiol E2.
Low levels stimulate pubertal growth spurt
higher levels cause fusion of epiphyseal plates
How to dx GDPP?
GnRH analog stimulation test
–if gonadotropin levels are induced by GnRH stimulation–GDPP (if not: GIPP)
Random LH screening test
–LH of <0.1 is prepubertal. If >0.3= pubertal
Tx for GDPP or GIPP?
Medical castration: GnRH agonists given constantly or antagonists; anti-estrogen/androgen
Give glucocorticoids if congenital adrenal hyperplasia
SRY protein?
Causes medulla of bipotential gonad to develop into testis
What causes wolffian duct to degenerate in females? What does it form in males?
Absence of testosterone–degeneration wolffian duct
Testosterone from testis causes wolffian duct to form seminal vesicle, vas deferens, and epididymis.
What controls prostate development?
DHT
What is the Anti-mullerian hormone?
From testes; causes mullerian ducts to degenerate
what do mullerian ducts form?
fallopian tube, uterus, and upper part of vagina
What is the fxn of aromatase?
Converts testosterone to E2
