Puberty Flashcards
In boys, what indicates the start of puberty?
Testes larger than 3mL in volume or >2.5cm in diameter.
In girls, what indicates the start of puberty?
Breasts noted or palpable and enlargement of areola.
What is the effect of oestrogen on the breasts?
Causes:
- Ductal proliferation
- Site specific adipose deposition
- Enlargement of the areola and nipple
Differences between prepubertal and pubertal-adult uterus
Prepubertal Uterus
- Tubular shape
- 2-3cm
- 0.4-1.6ml
- Endometrium single layer of cuboidal cells
Pubertal - Adult
- Pear shaped
- 5-8cm
- 3-15ml
- Endometrium increased thickness
Differences between prepubertal and pubertal-adult ovaries
Prepubertal Ovaries
- 0.2-1.6ml
- Non-functional
Pubertal Ovaries
- 2.8-15ml
- Multicystic
What is adrenarche? What does it cause?
Maturation process of the adrenal gland observed in humans
Development of androgen producing zona reticularis
Peaks around 20 years of age
Increased levels of DHEA and DHEA-S which are precursors of androgen hormones
We see advanced bone age, axillary hair, oily skin, mild acne and body odour
More pronounced in obese. children.
Describe the HPG axis
- Hypothalamus releases GnRH
- Anterior pituitary releases LH, FSH
- Gonads ovaries - oestrogen
- Gonads testes - testosterone
- Sex hormone action in body
What is idiopathic central precocious puberty? Is it more common in males or females?
Precocious puberty in girls is defined by the development of sexual characters before the age of 8 years.
Precocious breast development is usually due to the premature activation of the hypothalamo-pituitary-ovarian axis, defining central precocious puberty
80% of CPP are females
It is RARE for males to go into CPP, if they do, we need to RULE OUT brain tumours - males presenting usually indicates something sinister.
What is precocious pseudopuberty and how do we treat?
- Looks like normal puberty with gonadal development and puberty but the GnRH is not activated
- The most common thing is adrenal sex hormone excess or secreting tumours of the gonad, brain, retroperitoneum, mediastinum and liver secreting hCG which has similar function as LH and FSH which stimulates the gonads and leads to sex hormone action
Treat = GnRH super agonist to suppress pulsatility of GnRH secretion
Is delayed puberty more common in males or females?
More common in males
Cause for concern if females present with delayed puberty.
Occurs in about 3% of children
- Hypogonadotrophic hypogonadism: Sexual infantilism related to gonadotrophin deficiency
- Hypergonadotrophic hypogonadism: Primary gonadal problems (testes or ovaries)
What can an X-ray of the left hand show us?
Delayed bone age in GH deficiency or Advanced bone age in precocious puberty.
Early puberty can also cause short stature as bones mature quicker.
What is the difference between hypogonadotrophic hypogonadism and hypergonadotrophic hypogonadism?
Hypogonadotropic hypogonadism:
- Problem with hypothalamus or pituitary where there is underactivation of gonads through reduction in hypothalamus and pituitary
- This is a symptom, not a diagnosis so there can be many causes - tumours etc
Hypergonadotropic hypogonadism:
- Where the gonads are not functioning properly so the hypothalamus (GnRH) and pituitary (LH, FSH) are over acting to produce response
What is the diagnostic dilemma in delayed puberty?
No gold standard to differentiate between central hypogonadotropic hypogonadism and constitutional delay in growth and puberty so we usually need to wait and diagnosis can take some time.
What is constitutional delay in growth and puberty?
Children experience delayed puberty compared with peers
More common in boys
Likely to be short for their age with history of normal growth
Delays in bone. maturation and delay in adrenarche
Frequently there is a family history of puberty delays too
Cause for hypergonadotrophic hypogonadism in males and females?
Females = turners syndrome Males = Klinefelter's syndrome
