Paeds: Puberty Flashcards
What hormone is needed to stop bone growth (bone fusion)?
Oestrogen
What hormones released from the hypothalamus and pituitary control puberty?
1) GnRH (gonadotropin releasing hormone) by hypothalamus
2) LH
3) FSH
4) Neuroendocrine hormones
What hormones released elsewhere in the body control puberty in women?
1) Oestradiol
2) Progesterone
3) Adrenal androgen precursors
What hormones released elsewhere in the body control puberty in men?
1) Testosterone
2) Dihydrotestosterone (DHT)
3) Adrenal androgens
4) Oestrodiol
What is gonadarche?
Activation of the gonads by LH and FSH
What is adrenarche?
Increase in production of androgens by the adrenal cortex leading to apocrine body odour and acne
What is thelarche?
Appearance of breast tissue due to oestrodiol
What is menarche?
First menstrual bleed due to oestradiol on endometrial lining (non-ovulatory)
What is spermarche?
First sperm production incl. nocturnal sperm emissions (due to FSH, LH stimulating production of testosterone)
What is pubarche?
Appearance of pubic (and axillary) hair, due to androgens
What is the role of oestradiol and progesterone in female puberty?
Menstruation
What are the roles of oestrodiol in female (and male) puberty?
1) Breast development
2) Growth acceleration
3) Skeletal maturation
How is oestradiol made from androgens (testosterone?)?
Via the enzyme aromatase
What is the action of LH in males?
Stimulate Leydig cells
What is the action of FSH in males?
Stimulate Sertoli cells
What extra hormone produced by gonads inhibits gonadotroph cells in the pituitary?
Inhibin (inhibin B in males)
What is the role of testosterone in male puberty?
1) Increased muscle mass
2) Penile growth
3) Deepened voice
4) Hair growth
At what time of the day should you test someone’s hormone levels and why?
First thing in the morning
- There is a surge of hormones in the morning
- Timing is circadian
What kind of puberty can happen in infancy?
Mini-puberty
Why are gonadotropins low in childhood?
GnRH neurons are suppressed
Why does do LH and FSH increase in menopause?
Bc negative feedback from oestrogen is occurring
What is typically the first stage of puberty and what happens after that?
Adrenarche - then breast/testicular development then pubic hair
How long does puberty take in women?
2-2.5 years
What are the stages of puberty in women?
1) Thelarche (breast buds) - age 10
2) Pubic/axillary hair
3) Menarche (first period) - age 12-13
When is peak height velocity for females, after which is steeply falls?
Age 11.5
When do girls generally stop growing?
After they get their period
When does puberty typically complete/finish in women?
Age 14
What are the stages of puberty in men?
1) Increased in testicular volume (11.5)
2) Pubic hair stage 2 (12)
3) Sperm in urine (14.5)
4) Completion of puberty, pubic hair stage 5 (15)
5) Strength spurt (15.5)
When is peak height velocity in males after which it steeply falls?
Age 13.5
What is the last stage of puberty in males that is equivalent to period in women?
Facial hair and voice break
What question should you ask males to determine when puberty finished?
When they started shaving
Describe the tanner stages of male genitalia/hair development
- 1-5 for genital size and pubic hair
- 1-3 for axillary hair
- 1 = nothing
- 2 = first show
What is the normal adult testicular volume?
20-25 ml
At what testicular volume does it go from pre-pubescent to pubertal?
4ml
Describe the tanner stages of female breast, hair and period development
- B1-5 for breast
- P1-5/6 for pubic hair
- A1-3 for axillary hair
- P0 or P1 for period
If you’re not sure which tanner stage someone is at how should you describe it?
1) Pre-pubertal
2) In puberty
3) Finished puberty
What are the determinants of pubertal timing?
1) Genetics - most important, when parents had first period/shave e.g. if parents were delayed know it is normal for family
2) Environment
3) Race - Afro-Caribbean girls/boys tend to go into adrenarche early
4) Exercise
5) Health status/medication
How does exercise affect pubertal timing?
- Intense physical activity switches off the pubertal axis
- Body knows that women isn’t in a state to have a baby e.g. not enough fat
How does health status/medication affect pubertal timing?
- If can’t sustain pregnancy or not in a healthy state to have a child
- High dose steroids delays/blocks periods but still have adrenarche
What are other changes associated with puberty?
1) Anaemia
2) Gynaecomastia
3) Acne
How common is anaemia in boys and girls aged 12-15 years?
1) Girls - 2% incidence of anaemia, 9% incidence of iron deficiency
2) Boys - < 2%
Describe gynaecomastia in teenage boys
- Approx ½ of teenage boys have gynaecomastia - average age 13, not much can do
- Persists for 6-18 months - check genetics and oestrogen
- More likely if fatter - fat gets aromatised to oestrogen
What causes acne in puberty?
- Caused by androgenic stimulation
- Higher serum levels of dehydroepiandrosterone sulfate (DHEAS)
