L6 - Physiol and Disorders of Puberty COPY Flashcards
PHYSIOL OF PUBERTY
i) what is the definition of puberty?
ii) name three physical changes that may be seen in boys and girls
iii) what is the first change normally seen in girls? what age range does it occur?
iv) what does pubic hair dev depend on?
v) what is usually the last thing to happen in girls? what is the mean age for this to happen?
i) stage of physical maturation in which an individual becomes physiologically capable of sexual reproduction
iI) growth spurt, secondary sex characs, menarche/spermatogenesis
iii) breast dev is normally seen first - between 8-13 yrs
iv) pubic hair is dependent on adrenal function, not hormones
v) menstruation usually happens last in girls - 13yrs is mean age
ENDOCRINE CHANGES IN PUBERTY
i) when is HPG synchrony established?
ii) how is GnRH affected by neural mechanisms until puberty?what happens to GnRH release between 6-9yrs?
iii) what happens to ovaries/testes in this time?
iv) what is the final endocrine change seen in puberty?
v) which hormone is responsible for pubic and axillary hair?
i) HPG axis extab in foetal development
ii) GnRH is supressed by neural mechs until puberty
- between 6-9yrs there is pulsatile nocturnal GnRH release at night
iii) ovaries/testes become sensitised to the effects of FSH and LH
iv) final phase is the development of positive and negative feedback mechs
v) ACTH stimulates the adrenals > pubic and axillary hair
TESTES
i) which cells produce sperm? which hormone are they under the influence of?
ii) which cells produce testosterone? which hormone are they under the influence of?
iii) what produces 95% of testos and what produces 5%?
iv) what is testosterone converted to in target organs?
v) what testicular measurement is important in clinical assessment? what can this signal the start of?
i) sertoli cells produce sperm and are under the influence of FSH
ii) leydig cells produce testosterone and are under the influence of LH
iii) 95% testos from testes and 5% from adrenals
iv) testos is converted to DHT in target prgan
v) testicular volume is important
- >4ml can indicate start of puberty (use orchidometer)
THE OVARIAN CYCLE
i) what oestrogen levels are seen in the follicular cells?
ii) which phase occurs after ovulation?
iii) what happens to the endometrial lining after ovulation occurs?
iv) which hormone surges at ovulation?
i) increasing oestrogen levels that peak before mid cycle surge of LH
ii) luteal phase (corpus luteum secretes progesterone)
iii) post ovulation = thickening of endometrium
iv) LH and FSH surge at ov
AGE OF MENARCHE
i) name three things its related to
ii) is the mean age falling or increasing over time? what is the mean age now
iii) when may 1 in 8 girls now reach menarche?
iv) how is body weight and % fat implicated? what is the mean weight at menarche? which people may have late onset?
i) general health, genetics and nutritional factors
ii) falling over time - mean age is now 12.8yrs
iii) 1 in 8 girls reach menarche in primary school
iv) mean body weight 47kg
- athletes and anorexia patients may have late onset
ADRENARCHE
i) what is it?
ii) what are adrenal androgens responsible for (2)
iii) which layer of the adrenal cortex is stimulated by ACTH?
iv) which two androgen levels rise in both boys and girl? what ages do they start and what age do they reach adequate levels?
v) what may premature adrenarche be linked to?
i) activation of adrenal androgens
ii) axillary and pubic hair
iii) zona reticularis is stim by ACTH
iv) DHEAS and androstenedione
- girls start at 6yrs and adequateby 8yrs
- boys start at 8yrs and adequate by 10yrs
v) premat adrenarche can be linked to rising obesity levels
OVERVIEW OF PUBERTY
i) what is the first clinical sign seen in girls? what is the last sign?
ii) what happens later in boys than girls?
iii) what happens first in boys? what happens last?
iv) what is the mean age of start of puberty for boys and for girls?
v) do boys or girls spend more time going through puberty?
i) breast dev is first clinical sign seen in girls
- menarche is last sign
ii) growth spurt happens later in boys than girls
iii) increased testicular volume is first in boys and deep voice is last
iv) girls = 10.2 years and boys = 11.2 years
v) boys spend more time going through puberty than girls
PRECOCIOUS PUBERTY
i) what age is seen as precocious in girls and in boys?
ii) how can it be defined?
iii) what hormone is responsible for central or true precocious puberty?
iv) how can peripheral/pseudo-precocious puberty be characterised?
v) which two other events can start early but still be normal variants
i) girls = under 8 yrs and boys under 9yrs
ii) presence of true pubertal features at a young and inappropriate age (breast dev in girls and testic vol >4ml boys)
iii) ACTH axis switches puberty on = gonadotrophin dependent
iv) pseudo precocious is gonadotrophin independent
v) premature solo thelarche (breast growth) and adrenarche (axillary hair) can be normal variants
EARLY ONSET PUBERTY CONCERNS
i) what % of boys have an underlying/sinister cause?
ii) what is a reason to treat it?
iii) name a rare condition that can trigger precocious puberty
iv) how may height and weight be affected? what LH/FSH levels may be seen?
v) how may bones be affected
i) 80%
ii) psychological effects are reason to treat
iii) hypothalamic hamartoma
iv) high height and weight
- elevated levels of LH/FSH
v) advanced bone age due to increased oestrogen
PRECOCIOUS PUBERTY TREATMENT
i) what analog therapy may be given? what does this do?
ii) what ultimately needs to be achieved?
iii) what age would this treatment be stopped?
iv) what test can be done to see LH/FSH levels?
i) LHRH (LH releasing hormone)
- lower amount of testos made by testes
ii) need to stop further pubertal progression
iii) stop at 10-12yrs when puberty needs to be resumed
iv) do LHRH test to see if LH/FSH rise in relation to stimulation
NORMAL VARIANTS
i) what is premature thelarche? what age group may this be seen in?
ii) is increased LH/FSH/menarche seen in premat thelarche
iii) what is premature adrenarche? what may these patients be investigated for?
i) isolated breast development seen in <2-3yrs age
ii) do not see increase in LH, FSH or menarche
iii) premat adrenarche is isolated pubic hair development
- need investigating for androgen producing tumours by doing a urinary steroid profile
PSEUDO-PRECOCIOUS PUBERTY
i) name two things that can cause it in females
ii) name two things that can cause it in males?
iii) is it gonadotrophin dependent or independent?
i) ovarian cysts, congenital adrenal hyperplas
ii) CAH, adrenal/leydig cell tumour
iii) gonadotrophin indep
CONGENITAL ADRENAL HYPERPLASIA
i) which enzyme is there a defect in? what does this cause?
ii) what may this cause an increase in?
iii) will there be breast bud dev? will LH/FSH be raised?
iv) what two things would you expect to be raised in the urine?
v) how may a baby present? (2)
vi) how can it be treated?
i) 21 alpha hydroxylase (for synth of MC and GCs) causes excess androgen production
ii) increase in pubic hair
iii) no breast bud dev and LH/FSH not raised
iv) see raised androgens and 17OH progesterone (step before 21AH)
v) babies can present with salt wasting and virilisation
vi) treat with hydrocortisone
DELAYED PUBERTY
i) how is it defined?
ii) what may be a sinister underlying cause?
iii) how will stature be affected?
iv) what is a possible long term sequale?
i) absence of true pubertal onset at an appropriate age
ii) adenoma
iii) short stature
iv) reduced bone mineralisation
KLINEFELTER SYNDROME
i) what is the karyotype?
ii) will the person be tall or short?
iii) does it affect males or females?
iv) what hormone may they be deficient in? what does this cause?
v) how may their genitals be affected?
vi) what therapy must be given lifelong?
i) XXY
ii) tall
iii) only affects males
iv) androgen deficiency which causes azoospermia and infertility
v) microgenitalia
vi) lifelong testosterone replacement therapy
