3. Puberty and Abnormalities of Menstruation Flashcards
What is the difference between primary and secondary sexual characteristics?
Primary are established before birth, secondary only come when the reproductive system is activated in puberty.
What are the ranges of ages for the beginning of puberty in males and females?
Males: 9-14 years
Females: 8-13 years
What are the changes in the male at puberty?
Genital development begins, pubic hair growth (adrenarche), spermatogenesis begins, growth spurt.
How much do males grow per year during their growth spurt?
10cm
What are the changes in the female at puberty?
Breast bud (thelarche), pubic hair growth (adrenarche), menstrual cycle (menarche), growth spurt.
How much do females grow per year during their growth spurt?
9cm
What initiates puberty?
The brain.
What hormonal changes are associated with the start of puberty?
Steady rise in FSH and LH caused by pulsatile GnRH.
What is the most important factor in the timing of puberty?
Body weight.
What is the critical weight for menarche?
47kg
What is the growth spurt starting weight for males and females?
Males: 55kg
Females: 30kg
What does adrenarche (pubic and axillary hair) depend on?
Androgens in both sexes.
How do growth spurts differ between males and females?
Girls have earlier and shorter growth spurts so men are generally larger due to their longer and faster growth spurt.
What do growth spurts depend on?
Growth hormone and steroids in both sexes.
What ends growth spurts and how does this differ between males and females?
Ends in epiphyseal fusion. In girls, oestrogen closes the epiphyses earlier.
What is thelarche (breast development) dependent on?
Oestrogen.
What is male genital development dependent on?
Testosterone.
What is precocious puberty?
The signs of puberty before the age of 8 in girls or 9 in boys.
What can precocious puberty be due to?
Neurological causes (early stimulation of central maturation giving early, inappropriate GnRH secretion - pineal tumours or meningitis), or uncontrolled gonadotrophin or steroid secretion (hormone secreting tumour).
When is pre-menopause?
> 40 years.
What are the changes in the menstrual cycle during pre-menopause?
Follicle phase shortens so ovulation is early or absent, less oestrogen secreted so less negative feedback and LH and FSH rise (FSH rises more-so as loss of inhibin), reduced fertility but still possible to get pregnant.
What is the menopause?
Cessation of the menstrual cycle as the female has run out of follicles.
What is the average age of menopause?
49-50 years.
What are the hormonal changes in menopause?
Oestrogen levels fall dramatically so less negative feedback and LH and FSH rise (FSH rises dramatically due to loss of inhibition from inhibin).
What are the vascular effects of the menopause?
Hot flushes in 80% of women, transient rises in skin temperature and flushes.
How are hot flushes relieved?
By oestrogen treatment.
What are the effects of the menopause on oestrogen sensitive tissues?
(Uterus, cervix, vagina, breasts, skin, bladder)
Uterus - regression of endometrium, shrinkage of myometrium, shrinks away into a very small organ.
Thinning of cervix.
Vaginal rugae lost - thinner, less distensible.
Involution of some breast tissue.
Changes in skin.
Reduction in bladder tone.
What are the effects of the menopause on bone?
Bone mass reduces by 2.5% per year from increased reabsorption relative to production. Causes osteoporosis.
What can limit the effects of the menopause on bone?
Oestrogen therapy.
What are the goals of hormone replacement therapy?
Relieves symptoms of the menopause and can limit osteoporosis.
What is amenorrhoea?
Absence of periods for at least 6 months.
What is primary amenorrhoea?
Never had a period, absence of menses by 14 with absence of secondary sexual characteristics or absence by 16 with normal secondary sexual characteristics.
What is secondary amenorrhoea?
Established menstruation has ceased for three months in a woman with a history of regular cyclic bleeding or nine months in a woman with a history of irregular periods.
What is oligomenorrhoea?
Infrequent periods occurring at intervals of 35 days to 6 months.
What is dysmenorrhoea?
Painful periods.
What is menorrhagia?
Heaving periods. Excessive >80ml and prolonged >7 days uterine bleeding.
What is cryptomenorrheoa?
Periods occur but aren’t visible due to obstruction in the outflow tract.
What is dysfunctional uterine bleeding (DUB)?
Abnormal bleeding, no obvious organic cause.
What are anovulatory cycles?
No ovulation/luteal phase, oligo/amenorrhoea +/- menorrhagia.
What are ovulatory cycles?
Normal menstrual cycles with dysmenorrhea/mastalgia (sore breasts).
What are the possible origins of amenorrhea?
Hypothalamic/pituitary, ovarian tract, or outflow tract (uterus, vagina, cervix).
What is hypothalamic/pituitary amenorrhoea?
Inadequate levels of FSH lead to inadequately stimulated ovaries, which then fail to produce enough oestrogen to stimulate the endometrium of the uterus -> amenorrhoea.
What can cause primary and secondary hypothalamic amenorrhoea and secondary pituitary amenorrhoea?
Primary - Kallmann syndrome = inability to produce GnRH => can’t produce FSH.
Secondary - exercise amenorrhoea = from exercise, stress amenorrhoea = from eating disorders and weight loss below 47kg critical weight.
Secondary pituitary - Sheehan syndrome = hypopituitarism, hyperprolactinaemia, haemochromastosis = iron overload.
What is gonadal/end-organ amenorrhoea?
The ovary doesn’t respond to pituitary stimulation so there are low oestrogen levels. Lack of negative feedback from oestrogen means FSH is elevated to levels in the menopausal range.
What are the causes of primary and secondary amenorrhoea?
Primary: gonadal dysgenesis, androgen insensitivity syndrome, receptor abnormalities for FSH and LH, congenital adrenal hyperplasia.
Secondary: pregnancy, anovulation, menopause, polycystic ovarian syndrome, drug-induced.
What is outflow tract amenorrhoea?
Hypothalamic-pituitary-ovarian axis is functional so FSH is normal.
What are the causes of primary and secondary outflow tract obstruction?
Primary: uterina - Mullarian agenesis in 15%; vaginal - vaginal atresia, cryptomenorrhoea, imperforate hymen.
Secondary: intrauterine adhesions in Asherman’s syndrome.
How is amenorrhoea managed?
Depends on the cause. If insufficiency in hormone, hormone replacement. If lifestyle, modify factors.
What are the causes of dysfunctinoal uterine bleeding?
90% from when ovulation isn’t occurring so the corpus luteum doesn’t form to release progesterone meaning oestrogen is produced continuously -> overgrowth of uterine bleeding and subsequent bleeding.
10% with ovulation but progesterone secretion is prolonged due to low oestrogen -> irregular shedding of uterine lining and erratic bleeding.
What causes of bleeding must be ruled out in diagnosing DUB?
HCG, TSH to exclude pregnancy/thyroid problem, coagulation workup, smear to exclude cancer, sample endometrium.
What is menorrhagia from?
Secondary to distortion of the uterine cavity, leading to the uterus being unable to contract down on open venous sinuses in zona basalis.
How is menorrhagia managed?
With progesterone.
