Gonads and puberty Flashcards
(22 cards)
What is puberty?
The physiological, morphological, and behavioural changes as the gonads switch from infantile to adult forms
What are the definitive signs of puberty?
- Girls = menarche (1st menstrual bleeding)
* Boys = first ejaculation, often nocturnal
What is the involvement of testicular androgens in male puberty?
- External genitalia and pubic hair growth
* Enlargement of the larynx and laryngeal muscles (voice deepening)
What is the significance of testicular size in male puberty?
Real puberty starting is often measured by testes size >3ml (>2.5cm in largest diameter)
How does oestrogen affect breast development in females?
- Induces ductal proliferation
- Causes site specific adipose deposition
- Causes enlargement of areola and nipple
How do the uterus and ovaries change in puberty?
- Uterus develops from a tubular shape pre-puberty to a pear-shaped post-puberty
- Endometrium thickens
- Ovarian volume increases and becomes multi-cystic and functional
What happens in the maturation of the vagina in puberty?
- Dulling of reddish colour and thickening of epithelium
- pH becomes more acidic
- Length increases
- Secretion of clear discharge in the months before menarche
Define precocius puberty
The early onset of secondary sexual characteristics - before 8yrs for girls or 9yrs for boys
How does true precocious puberty differ from pseudo precocious puberty?
True involves the activation of the hypothalamus to send signals to activate the HPG axis system whereas pseudo doesn’t have hypothlamic activation
How do you differ between true and pseudo precocious puberty?
• GnRH test of injecting the hormone and measure after 30 and 60 mins
- True shows LH and FSH stimulation in pubertal range
- Pseudo has stimulation in the pre-pubertal or supression range
How would you treat true precocious puberty?
GnRH superagonist to supress the pulsatility of GnRH secretion
Give 3 causes of true precocious puberty
- Idiopathic
- CNS disorder
- CNS tumour
Give 3 causes of pseudo precocious puberty
- Increased androgen secretion
- Gonadotrophin or oestrogen secreting tumours
- Ovarian cyst
What is hypogonadotropic hypogonadism?
Primary gonadal failure
What is hypergonadotropic hypogonadism?
Sexual infantilism relation to gonadotropin deficiency (secondary or tertiary failure)
In relation the HPG axis problems, what are primary problems?
Problems in the primary organ i.e. the gonads
In relation the HPG axis problems, what are secondary problems?
Problems in the pituitary gland
In relation the HPG axis problems, what are tertiary problems?
Problems in the hypothalamus
In girls, what would be indications for investigation of delayed puberty?
- Lack of breast development by 13yrs
- More than 5yrs between breast development and menarche
- Lack of pubic hair by 14yrs
- Absent menarche by 15-16yrs
In boys, what would be indications for investigation of delayed puberty?
- Lack of testicular enlargement by 14yrs
- Lack of pubic hair by 15yrs
- More than 5yrs to complete genital enlargement
What key points of family history may indicate a constitutional delay of growth and puberty?
Late menarche in mother or sisters or delayed growth spurt in father
What are import points to ask about in a history of delayed puberty?
- Totally absent or started then stopped
- Family history of constitutional delay, infertility or delayed puberty
- Perinatal history, prior medical illness, medication
- Psychological deprivation, nutrition, exercise intensity
- Neurological symptoms
- Hypoglycaemia
- Cancer history and treatment
- Testicular injury
