Physiology of growth and development Flashcards
what is puberty
onset of sexual maturity, when the secondary sexual characteristics appear and the reproductive organs become functional
when does puberty start in terms of hormones
when the hypothalamus resumes producing GnRH and we see down stream effects of sex hormones
what is the tanner scale
No hair.
Stage 2: Downy hair.
Stage 3: Scant terminal hair.
Stage 4: Terminal hair that fills the entire triangle overlying the pubic region.
Stage 5: Terminal hair that extends beyond the inguinal crease onto the thigh.
what is adrenarche
the spontaneous release of weak androgens from the adrenal glands. Ordinarily precedes puberty by 2 years
when do children experience growth spurts due to GH
postnatal after first 2 years of life and pubertal growth spurt during adolescence
when does puberty begin in boys and girls
girls 11
boys 13
what hormone halts bone growth
oestrogen
what does GH do to soft tissues
increases the size of the cells and increases the number of cells
LH acts on what cells to release androgens which with with aromatase make oestrogen from what cells. these cells also make inhibin which inhibits FSH on anterior pituitary. oestrogen inhibits both on hypothalamus and ant pituitary
theca cells and then granulosa cells
leydig cells make testosterone from androstenedione and Sertoli cells lead to what
spermatogenesis
in females what does oestrogen do and in males to
prompts breast development , ovarian and uterine maturation, fat redistribution and bone growth. In males, testosterone prompts bone growth, body hair and penile, scrotal and testicuarl maturation as well as first eject.
in uk on average females are regarded as having precocious puberty if breast tanner II on menarche before what age
delayed puberty if breast tanner II after hat age or menarche after
for males this range is from 9-14
before 8 years
13 years
15 years
girls growth spurt first but boys longer
what to hormones regulate GH
GHRH and somatostatin growth hormone inhabiting hormone GHIH
15yr old small and struggling at school and hasn’t reached menarche. wide neck and spaced nipples and soft systolic murmur. breast tanner I and oubic tanner III and mild body odour. FSH and LH are at upper limit 3 times is oestrogen high or low
gem
what is responsible fro her pubic hair
oestrogen low fault with the ovaries
adrenal glands - adrenarche
is kleinfelters do they start puberty on time
yes and then it tails off
review 14 year old girl without menarche. otherwise health and performs. breast Tanner ! and no pubic hair. mother menarche at 15
does she have delayed puberty
what tests would you like to do
yes
FSH and LH and oestrogen - always do biochemistry first
might also want to do routine bloods to rule out hypothyroidism and anaemia and consider preg test
18 year old boy no developing. small testes, microphallus and absent chest hair. voice not broken and not interested in sex and denies erections. and no sense of smell
what tests and what condition
FSH and LH and testosterone
MRI Brain- olfactory bulbs, bone age scan, genetic testing (KAL1), prolactin, cortisol, TSH and T4, GnRH challenge
kallmann syndrome - gonads work if simulated - administration of sex hormones
17yr old boy. puberty started at 14 and started shaving at 16. she had erections and ejaculated. last two months these have abrubtly stopped and he’s developed mild gynaecomastia.
FSH LH and testosterone are below normal levels what is going on
hyperprolactinaemia - puberty has been interrupted therefore this is acquired.
prolactin inhibits GnRH
hypogonadotrophic hypogonadism
7 year old daughter breast tissue development and has vaginal bleeding. Breast tanner III with pigmentation of the aerial. no pubic hair and mild LIF pain.
what likely hormones
low FSH and LH and high oestrogen
USS or MRI - where is the oestrogen coming from as not driven by pituitary. abdominal clue as ectopic cause like ovarian tumour or cyst.
gonadotrophin-indepenedt precocious puberty
most common cause of
gonadotrophin-indepenedt precocious puberty
maine cafe au last spots and dysplastic bones do you know diagnosis
McCune albright syndrome MAS - gonadotrophin independent precocious puberty classic triad of cafe au lait( MAINE) , precocious puberty( multiple cysts normally female) and fibrous dyspalsis
commonly confused with neurofibromas
8 year old girl pubic hair and requires deodorant. pubic tanner III and breast tanner I. no sydmorphic features - what tests
FHS, LH oestrogen and testosterone. this all at normal levels and no further development this is girl is going through adrenarche. - commonly weak and benign as small release
8 year old boy shot u in height. genitals developed rapidly. energetic boy and has tanner 4-5 midl acne and body odour. bursts into spontaneous laughter without cause
blood show very highFSH,LH and testosterone what is it
what test to confirm diagnosis
gonadotrophin- dependent as testoerone is responding to the FSH and LH
MRI and brain stem
what is an example of gonadotrophin dependent precocious puberty
hyopthalamic hamartoma
affects boys more
precocious puberty and gelastic epelipesy
causes spontaneous GnRH release from hypothalamus
also caused by hypothyroidism, head tuaem, CNS infection or tumour
precocious puberty caused by
gonadotrophin-independent - production of sex hormones - goandtophisn not elevated
gonadotrophin-depends - high sex hormone with gonadotrophin elevated
actions of GH
lipolysis
protein synthesis
decrease glucose uptake
sitmateles cell growth and proliferation icnlduign chondrocyte sand mypobalsts
13yr old boy has prognathism. Tanner 4
tests
GH, IGF-1, prolactin, TSH and T4, LH and FSH and cortisol
glucose tolerance test after - this would suppress the GH
if GH and IGF-1 why do you perform a glucose tolerance test
in a healthy patient the GH should be suppressed
growth hormones works directly and indirectly through IGF-1. normally GH is suppressed by glucose. excess growth hormone before the fusion of the epiphysis results in gigantism. after the plate is acromegaly.
