Puberty (lec 35) Flashcards
Genetic sex is?
combo of sex chromo at conception
Gonadal sex is?
testes or ovaries
determined by presence/absence of Y
Phenotypic sex is?
anatomic
determined by gonadal
Sex Determining Region (SRY) of Y chromo purpose?
makes testis determining factor (TDF)
in absence of TDF -> gonads become ovaries
Gonadal development?
1st 5 wks: gonads are indifferent
TDF -> testies wks 6-7
Ovaries wk 9
In males, Wolffian ducts become?
Mullerian ducts become?
via testosterone stim ->
epidid, deferens, sem vesc, ejac ducts
via antimullerian hormone ->
ducts atrophy
DHT role in male development?
(Testosterone changed to DHT by 5a-reductase)
wk 9-10 DHT stim differentiation of external genitalia
absence of DHT -> female gen development
In females, Mullerian ducts become?
Wolffian ducts become?
No hormone needed ->
fallop tubes, uterus, up 1/3 vagina
atrophy
Androgen Insensitivity Synd (Testicular Feminization)?
XY w/ no fxnl androgen receptors
Testes develop -> secrete AMH/testost
Both Wolffian/Mullerian ducts atrophy
Female external genitalia w/ blinded vagina,
Infertile,
Diagnosed at puberty
Female Pseudohermaphroditism?
XX w/ no 21-hydroxylase ->
no cortisol prdxn/excess androgen prdxn
Ovaries develop,
Mullerian develop/Wolff atrophy,
High androgens cause external genit to virilize,
Infertile
XY w/o SRY?
XX w/ SRY?
develop as female
develop as male
5α-reductase deficiency?
male pseudohermaphroditism (male internl/female external)
5a-reduc turns testosterone into DHT (necessary for external genitalia development in males)
XY w/ defective testis?
No testost prdxn = no internal genitalia, female-like external
XY w/ defective AMH?
Male and female internal with male external
wolf stim’d but mull not suppressed
Male puberty?
starts 9-14 yo
↑ testicle size
pubic hair
↑ penis size
Sperm/ejac develop ~ 13
Female puberty?
starts 8-13
thelarche (breasts) ->
pubarche ->
menarche
1st cycles w/o estrogen feedback so no ovulation
Pubertal timing due to?
↓ suppression of GnRH or
↓ sensitivity to - feedback of est/test
1st ↑ in GnRH release?
during sleep
↑ LH
Puberty ºcontrol is?
body fat (energy resources)
Leptin and puberty?
(Hormone from adipose)
regulates body weight/metabolism
stim puberty
Melatonin and puberty?
(hormone from pineal gland)
synchs circadian rhythm
inhib GnRH release
Precocious Puberty is?
2º development < 8F or <9M
Gonadotropin-DEPENDENT Precocious Puberty (GDPP) caused by? (3)
↑ gonadotrophins (LH, FSH)
CNS tumor
Idiopathic
Gonadotropin-INdependent Precocious Puberty (GIPP) caused by? (3)
Normal LH/FSH but ↑ gonadal hormones
Testicle/ovary disorder
Hormone-secreting tumors
GDPP epidemiology?
Tx?
F»M
Long-acting GnRH agonist:
Initial ↑ ↑ FSH/LH release ->
down-reg/desens receptors ->
↓ gondadotropins
GIPP tx?
tumor removal
Delayed puberty is?
lack of physical maturation 2 SD beyond mean
Hypogonadotropic Hypogonadism caused by? (3)
Low gonadotropins -> low gonad hormones
Deficient pulsatile release
Killman’s Synd
Hypergonadotropic Hypogonadism caused by? (3)
Low gonadal hormones -> high gonadotropins from no - feeedback
Gonadal streak
Turner’s
Kallman’s Synd?
M>F
Ø fetal migration of GnRH secretor neurons to hypothalm = ↓ gonadotropins
Tx: hormones
Turner’s?
XO = Ø neg feedback
Female genital tract, Ø fxnl gonads
Tx: GH then sex hormones
Klienfelter’s?
47 XXY
Feminization
Testicular failure
