Puberty CPC Flashcards
The physical and biochemical changes associated with activation of the hpg axis that leads to adult reproductive function.
Puberty
Gonadotropin levels are high/low after birth up to 2 years
high
Role of gonadotropin in neonates
due to release of suppression from maternal E/P–> gonadotropin release –> transient E,T secretion induced by high FSH/LH –> development of ovarian cysts in females
During childhood, FSH/LH are suppressed/upregulated
suppressed –> low level pulses –> E/T suppression due to central suppression of hypothalamus
Children with gonadal dysgenesis have FSH/LH levels similar/less than normal children
similar –> GnRH will stimulate FSH/LH in these agonadal children –> suggests hypothalamic regulation in childhood vs. gonadal regulation
Pre-puberty events
return of GnRH pulsatility -
____ is the marker for GnRH
LH –> able to measure peripherally//short half life so mirrors gnrh pulsatility (FSH has a longer half life and can’t mirror the pulses)
In early pre-puberty, LH pulse is observed ____
at night –> eventually occurs throughout the whole day
T/F at midpuberty, sufficient gonadal estrogen secretion leads to proliferation of the endometrium and the first menarche occurs
T
Cycles are anovulatory during the first ___ years following menarche
1-2
_____ is the first sign of puberty in males.
growth of testes
Adrenarche
increase in secretion of androgen precursors from the zona reticularis of the adrenal gland –> axillary and pubic hair
T/F adrenarche is under control of acth
F –> not under direct control
Gonadarche
activation of sex steroid secretion by ovary/testis –> breast tissue, sexual maturation
T/F adrenarche and gonadarche are regulated independently
T
T/F adrenarche occurs normally in individuals without normal gonads
T –> turner’s
T/F Gonadarche occurs in individuals with primary adrenal insufficiency
T
T/F premature adrenarche leads to premature gonadarche
F
Which stage of female pubertal development? breast development
thelarche
Which stage of female pubertal development? androgen production from adrenals
adrenarche
Which stage of female pubertal development? development of pubic/axillary hair
pubarche
Which stage of female pubertal development? onset of menstruation
menarche
T/F breast development before age 8 or after age 13 requires further evaluation in any girl
T
Puberty onset factors
genetic, environmental, toxic, nutritional, hormonal
T/F good genetic correlation in onset of puberty
T
Decreasing age of menarche attributed to better/worse nutrition, more/less physical activity, more/less obesity
better, less, more
GnRh pulsatile secretion modulated by ____ nucleus
arcuate
GABA ____ as gnrh increases at gonadarche
declines –> inacitvate receptor or reduce gaba –> premature menarche and ovualtion
GABA inhibits/coactivates GnRH
inhibits
NPY inhibits/coactivates GnRH
inhibits
T/F Leptin is necessary for gonadarche
T
_____ has a receptor ____ which stimulates GnRH and has a key role in activation of gonadotropic axis at puberty.
kisspeptin 121 and gpr54/kiss1
