Hellkatz: Physiology of Puberty Flashcards
Puberty
the final stage of maturation of the HPGA culminating in the adult phenotype> development of gonadal function and attainment of full sexual maturity and fertility
6-8 week period when the HPGA is biologically active and sex steroids are comparable w/ levels in early-mid puberty but there are NO peripheral effects
Mini-puberty in infancy
What causes the long period of pre-puberty state?
HPG suppression
When do children enter puberty?
when HPG suppression is released
What activates steroid production in the gonads during puberty?
Increase in pulsatile GnRH and FSH/LH>
leads to an increase in circulating estrogen (F) and testosterone (M)
**specifically diurnal changes in LH stimulate steroidgenesis in the gonads> leading to maturation of HPG axis > establishes NFB mechanism
How do height and weight affect onset of puberty?
Increased BMI/height> earlier onset
When does menarche occur during puberty?
near the end
height in middle
breasts/pubic hair early
pubic hair growth in response to development of adrenal zona reticularis> production of androstenedione and DHEA
Adrenarche
beast development d/t estrogens
thelarche
production of ovarian hormones and mature gamates
gonadarche
uterine response to ovarian hormones
menarche
When does growth velocity peak in F?
age 14
When is the peak velocity of growth in Males?
13-14
Completion 15.5 (later than girls)
precocious puberty
puberty in children 5-8
Why are children who have experienced precocious puberty shorter than average?
estrogen has a biphasic effect on epiphyseal growth
LOW levels of E2 favor growth spurt but HIGH fuse the epiphyses
2 types of precocious puberty
GDPP
GIPP
An idiopathic/CNS related cause leads to early activity of pulsatile acitivty of the HPG axis > Puberty EARLIER than expected and all signs are matched
GDPP
How do you dx GDPP?
GnRH stimulation test
If GnRH leads to increased LH > than it’s GDPP
If levels DONT increase than its GIPP
LH levels of .3 or more is indicative of…
PUBERTY
pre-puberty is less than .1
How do you treat GDPP?
medical castration:
- GnRH agonists/antagonists
- anti-estrogens/androgens
- GLUCOCORTICOIDS in a pt w/ adrenal hyperplasia
What causes GIPP?
ovarian cysts, leydig cell tumors, exogneous estrogen, pituitary tumors…. a lot of stuff
What is the pathogenesis of GIPP?
cause> one/TWO signs of puberty with no others (signs of stages are dissimilar)
Adrenarche can be a sign of…
tumor of hte adrenal gland
CAH (21-hydroxylase def)> DHEA and 17oh progesterone are increased
a display of bone age older than chronological age along with adrenarche in boys and thelarche in girls may be indicative of…
- tumors tha tsecrete hCG> bind LH> stimulate gonadal sex steroid synthesis
- Gonadal tumors> increase sex steroids but not gonadotropins
- exposure to sex steroid hromones
When is the bipotential stage of fetal development?
6 weeks
directs medulla of bipotential gonad to develop testis
SRY protein
Hormone from testis that causes mullerian ducts to DEGENERATE
anti-mullerian hormones
Converts wolffian duct to seminal vesicle, vas deferens and epidiymis
Testosterone
Gonadal cortex becomes ovary in the absence of this protein
SRY protein
Absence of this hormone caues wolffian duct to degenerate
testosterone
absence of this hormone allows mullerian duct to become fallopian tube, uterus and upper part of vagina
anti-mullerian
What organs are DHT sensitive?
penis and prostate
w/out DHT you can get a micropenis
causes of sexual ambiguity
hypogonadism, muatations in hormone production/receptors/signaling., sex chromosome loss, and mosaic individuals
