Endo. Puberty L4
Physiology of pubertyBetween early childhood and 8-9 yr of age (prepubertal stage )the hypothalamic –pituitary –gonadal axis is dormant as reflected by undetected level of LH & sex hormones testosterone in boys and Estradiol in girls .1-3 yr before onset of puberty low serum level of LH demonstrate during sleep in pulsatile fashion
. the pulsatile secretion of gonadotropins is responsible for enlargement and maturation of the gonads and the secretion of the sex hormones
in mid puberty the level of LH become evident even during day time and occur at about 90-120 minutes intervals
It is clear that GnRH is the primary if not the only , hormone responsible for the onset and progression of puberty
The effect of gonadal steroid (testosterone and estradiol )on bone growth and osseous maturation are critical , both aromatase deficiency and estrogen receptor defect result in delayed epiphyseal closure and tall stature in affected boys,
that is mean estrogen rather than androgen are responsible for process of bone maturation and epiphyseal fusion and cessation of growth
Estrogen also mediate the increased production of growth hormone which also responsible with sex hormone for pubertal growth spurt.
The onset of puberty vary and more correlated with osseous than with chronological maturation age
In female, breast bud(thelarche ) is first sign of puberty (10-11yrs) followed by pubic hair (6-12 months later ), the interval to menarche usually 2-2.5 yrs. peak height velocity usually start early 12 yr of age in girls &always precedes menarche (12.75yr)
Stages of female puberty(سلايد مهم يقرا في البور بوينت لصعوبة نسخه)
In male growth of testes(>2.5 cm) and thinning of scrotum is the first sign of puberty followed by pigmentation of scrotum and enlargement of penis .pubic hair then appeared . axillary hair appear in mid puberty in male unlike female growth acceleration appears after puberty . in male growth spurt usually 2 yrs later than in females .and growth may continue beyond 18 yrs .of age
Stages of male puberty
Precocious puberty :
Definition : onset of breast development before age of 8 yrs. In girls & onset of testicular development before age of 9 years in boys .
Etiology
Central (gonadotropin dependent true precocity )
Idiopathic
Brain lesions
Hypothalamic hamertoma
Brain tumors
Prolonged untreated hypothyroidism
Combined peripheral ¢ral
Treated CAH congenital adrenal hyperplasia
Familial male precocity
Peripheral (gonadotropin independent precocious puberty)
GirlsIsosexual (feminizing )
Ovarian tumors
Teratoma
Exogenous androgens
Mc Cune –Albright syndrome
Heterosexual (masculinizing)
CAH
Exogenous androgen
Adrenal &ovarian tumors
Boys
Isosexual ( Masculinizing)
CAH
Leydig cell tumor
hCG secreting tumors
teratoma
exogenous androgen
heterosexual (feminizing )
exogenous androgen
Clinical features
hair underarm &genitalia &for boys on face
acne
adult body odor
sexual development ( breast & testes )
emotional changes
mood swing
diagnosis
Hormonal levels(sex hormones )
Low estradiol level or undetected in girls
High testosterone (detectable in boys
Detectable level of LH in girls & boys
bone age (advance) osseous maturation
ultrasound for adrenal &uterus size
MRI or CT scan role out tumors
Treatment :
GnRH .analogs are effective in arresting pubertal progression in patient with central precocity like decapeptyle (zoladex ) monthly IM injection .
Medroxyprogesterone acetate some time used to :suppress puberty and arrest menses
Peripheral precocity :
Testolactone which inhibit conversion of testosterone to estrogen
Ketoconazole inhibit steroid biosynthesis 200mg tds
Cyproterone acetate Potent progestin & antiandrogen, inhibit androgens at the receptor level / supress gonadal & adrenal steroidogenesis : antigonadotrophic (100 mg/m2,, 2 divided doses)
Delayed puberty
Will be presented in gynecological course in details by gynecologist lecturer
Test question
Regarding pubertyCyproterone acetate , inhibit androgens at the receptor level
hypothalamic –pituitary –gonadal axis is active in prepubertal state
in mid puberty the level of LH become evident even during day time
Androgen rather than estrogen are responsible for process of bone maturation and epiphyseal fusion and cessation of growth
Menarche occur immediately after thelarche