Puberty Flashcards
Growth spurt
- Age
- Growth velocity
- Duration
8-14yrs girls
9-14 yrs boy
6-10cm/year
2.5 yrs duration
Thelarche
Start of breast development
8-13 yrs (11 average)
First sign of puberty (after growth spurt)
Pubarche
Start of pubic hair development
9-13 yrs in girls
- First sign of puberty in 25%
Adrenarche
Axillary/puberty hair formation
- ACTH stimulates zona reticularis
In girls
- 9.5-15 yrs
Causes of early adrenarche
- Ethnicity (Afro, middle east)
- XS androgen (i.e simple virilising CAH)
- Precocious puberty
Menarche
Start of menstruation
- Final phase of puberty in girl
10-16
- 13 average
Good percentage of fat required
- 16-24%
Good weight required
- 47.8Kg
Delayed menarche
- Athletes
- Menarche
Testicular volume
First sign of puberty in boys
- over 4ml= puberty
10-12mls
- Growth spurt
> 20 ml= adult testicles
Voice deepening
Last stage of puberty in boys
- Occurs 12-17 yrs
Timeline of female puberty
Average length is 2-3 years
- Growth spurt
- Thelarche
- Pubic hair
- Axillary hair
- Menarche
Mini puberty
GnRH nocturnal pulsation
- 6-9 yrs
- Occurs every 90-120mins
GnRH increases FSH and LH
Positive/negative feedback developed finally.
Endocrinology behind pubic and axillary hair development
ACTH increase stimulates adrenal glands
Urinary steroid profile
Steroid profiles in urine monitored.
Analyses adrenarche
Testes development
Sperm production
- FSH–> sertoli
Increased testosterone
- Leydig/ Adrenals
Testo—> DHT—> target tissue
Progression of puberty in boys
Total length
3-5 years
- Testicular volume
- Penile length
- Pubic hair
- Growth spurt
- Axillary/ pubertal hair
- Deep voice
Central/true precocious puberty
Gonadotrophin dependant early activation of gondal axis
- Puberty <8 in girls, <9 in boys.
Girls
- Mainly idiopathic
- Hypothalamic hamartoma
Boys
- Mainly hypothalamic tumour (hamartoma)
Other causes
- Brain trauma
- Cerebral palsy
Delayed puberty
Onset of puberty >14
Peripheral/ pseudo-precocious pubery
Early activation of the gonads/ adrenals that activate the axis
- Gonadotrophin independent
Examples
- CAH
- McCune-Albright
- Ovarian/ testicular/Adrenal tumour
CAH treatment
Hydrocortisone
- Compensates for lack of cortisol
LHRH analog
- Blocks LH/ FSH receptors
Hypothalamic hamartoma
Benign tumour that grows
Possible Effects
- Seizures
- Behavioural changes
Delayed puberty treatment
Testosterone for boys
- Given over a long period
Oestrogen for girls then progesterone
Kallmann syndrome
Genetic condition
- Hypogonadotrophic hypogonadism
Characterised by
- Delayed puberty
- Reduced sense of smell
- Can be infertile with increased risk of osteoporosis
Isosexual, feminising/ masculinising cause of pseudo-precocious puberty in females and males
Females:
- McCune Albright syndrome
- Ovarian tumour
- Adrenal tumour
Males:
- CAH
- Adrenal tumour
- Leydig tumour
Heterosexual, feminising/ masculinising cause of pseudo-precocious puberty in males and females
Females
- CAH
- Ovarian tumour
- Adrenal tumour
Males
- Adrenal tumours
Turner syndrome
- Incidence
- Triad of signs
1 in 2000 live female births
Signs
- Short stature
- Streak gonads (gonadal dysgenesis)
- Primary amenorrhoea
Turner syndrome
- Dysmorphic features
- Organ abnormalities
Dysmorphic features
- Webbing of neck
- Cubitus valgus
Organs
- Coarctation of aorta
- Horse shoe kidneys
Lymphedema.
