B8-060 Delayed Puberty Flashcards
[hormone] stimulates the development of secondary sex characteristics in females
estrogen
[hormone] is mildly anabolic and stimulates calcification
estrogen
[hormone] regulates behavior and secretion of gonadotropins
estrogen
[hormone] induce body hair
androgens
[hormone] influences sexual behavior
androgens
[hormone] promotes protein anabolism, somatic growth, and ossificaiton
androgens
[…] can be a significant source of androgen production in females
adrenal cortex
during puberty, […] provides negative feedback on the hypothalamus, leading to low levels of LH/FSH
estrogen
adrenarche refers to the production of […] a couple years prior to puberty
DHEA
one of the first changes occurring pre-puberty is the nocturnal rise in […]
GnRH
(leads to increased LH)
in childhood, high amounts of [neurontransmitter] inhibit GnRH neurons
GABA
during puberty, inhibitory GABA decreases and excitatory […] increases GnRH [3]
glutamate
NMDA
kisspeptin
how does the negative feedback of estrogen change throughout life?
in childhood, low levels of estrogen are needed to suppress GnRH
however, with age those low levels are no longer enough. Requires higher levels of estrogen to maintain LH/FSH
(decreasing sensitivity)
in hypogonadotropic hypogonadism, LH and FSH will be
low
(problem at level of pituitary)
in hypergonadotropic hypogonadism, LH and FSH will be
high
(problem at level of gonads)
Kallmans is […]gonadotropic hypogonadism
hypo
(neurons fail to migrate, anosmia)
Klinefelter’s is […]gonadotropic hypogonadism
hyper
Turner’s is […]gonadotropic hypogonadism
hyper
[what Turner stage]
no sexual hair
flat-appearing chest with raised nipples in females
stage 1
(pre-pubertal)
[what Turner stage]
pubic hair appears
testicular enlargement
breast buds form
Stage 2
(8-11.5 years)
[what Turner stage]
coarsening of pubic hair
penis size increases
breast enlarges
Stage 3
(11.5-13 years)
[what Turner stage]
coarse hair across pubis sparing thigh
penis width/glans increases in size
breast enlarges, raised areola
Stage 4
(13-15 years)
[what Turner stage]
coarse hair across pubis and thigh
penis/testis reach adult size
adult breast contour, areola flattens
Stage 5
> 15 years
earliest detectable secondary sexual characteristic is […] in females, and […] in males
breast bud development
testicular enlargement
precocious puberty is the appearance of secondary sexual characteristics under age […] in females and […] in males
8 in females
9 in males
central precocious puberty is caused by an increase in […] secretion
GnRH
(can be idiopathic or due to CNS tumors)
peripheral precocious puberty is […] independent
GnRH
due to increased sex hormone production of exposure to exogenous sex steroids
causes of peripheral precocious puberty
congenital adrenal hyperplasia
granulosa/leydig cell tumors
delayed puberty is defined as the absence of secondary sex characteristics by age […] in females and […] in males
13 in females
14 in males
chemotherapy/radiation would cause […]gonadotropic hypogonadism
hyper
male
47 XXY
klinefelters
small firm testis
infertility
tall stature
gynecomastia
female hair pattern
klinefelters
female 45 XO
Turners
short stature
streak ovary
broad chest, widely spaced nipples
webbed neck
Turners
defective migration of neurons and subsequent failure of olfactory bulbs to develop due to defective NCAM
Kallmanns
inheritance pattern of Kallmanns
X linked
(can be dominant or recessive)
what causes peak height velocity near puberty?
increased production of gonadal steroids
increased secretion of GH and IGF1
what causes the sharp decline in peak height velocity near puberty?
increased production of gonadal steroids also promotes calcification and closure of epiphyseal plates
homozygous mutation causing loss of ESR1 function causes
estrogen resistance
symptoms: amenorrhea, lack of breast development, epiphyseal plates don’t close
adverse effects of androgen therapy in adolescents
premature closure of epiphyseal plates
polycythemia
decreased spermatogenesis
increased LCL
male pattern baldness
growth spurt in girls typically corresponds to Tanner Stage […]
3
defect in androgen receptor resulting in female appearing genetic male
androgen insensitivity syndrome
female external genitalia with scant axillary or pubic hair
rudimentary vagina
uterus/fallopian tubes absent
androgen insensitivity syndrome
(patients develop normally functioning testis)
female phenotype
absent uterus
presence of breast development
androgen insensitivity syndrome in genotypic male
(T can be aromatized to estrogen allowing for breast development)
female presenting with:
primary amenorrhea
reduced/absent body hair
absent breast development
developmental delay
Kallmann syndrome
(vs Turners: normal intelligence and have some body hair/breast development)
what factors contribute to the “juvenille hiatus” [4]
elevated sensitivity of the hypothalamus to estrogen
high levels of inhibitory GABA in hypothalamus
low levels of kisspeptin secreted
secretion of estrogen from the ovary in females
