Repro 3 Flashcards
Describe the sequence of physiological and anatomical events that occur during puberty in males
Growth spurt
- starts later in boys and is roughly 10cm/year
- boys end up taller as they grow more before the spurt and during it.
- growth spurt ends with the fusion of epiphyseal plates.
Adrenarche (pubic hair)
- under the control of testicular androgens
- also causes deepening of the voice and development of genitalia - a defining moment in male puberty is nocturnal erections
Describe the sequence of physiological and anatomical events that occur during puberty in females
Thelarche
- around 8-11 years old
- gonadal steroids
Adrenarche
- 9-14 years old
- under the control of androgens from the adrenals.
Growth spurt
- 9cm/year
- 11- 14 years old
Menarche
- defining moment in female puberty
- normally during the middle of puberty
If the reproductive system can work before puberty, why doesn’t it?
The levels of GnRH is low, so there is nothing causing FSH and LH to be released.
This changes over time.
The hypothalamus slowly releases more and GnRH, to which the AP responds accordingly.
What is the main determining factor of initiating puberty?
Body weight.
- 30kg in girls for the growth spurt and 47kg for menarche
- 50kg in boys for growth spurt.
Lepton is a fat derived hormone so it also signals to the brain that the body is ready for puberty (obesity could cause precocious puberty)
Define precocious puberty, and it’s cause or causes.
Definition: signs of puberty before the age of 8.
Unknown causes.
Possibly:
- Neurological - pineal tumours and meningitis
- hormone secreting tumours
Discuss the pre-menopause
Usually begins at the age of around 40
- Erratic cycles
- follicular phase shortens
- early or absent ovulation
- less oestrogen secreted
- less oestrogen means there is less inhibition on FSH and LH, FSH rises more than LH.
- less inhibin released so therefore there is nothing inhibiting FSH release
- fertility decreases.
Describe the hormonal changes in the menopause
- no more follicles develop as the number of eggs is set before birth
- considerably less oestrogen
- FSH and LH rise dramatically
- no inhibin release
- occurs roughly 49-50 years of age.
Describe the changes on bone, vascularity and oestrogen sensitive tissues during the menopause.
Vascularity
- consequent of decrease oestrogen
- transient rises in skin temperature and flushing
- relieved by oestrogen treatment.
Bone
- oestrogen suppresses Osteoclast activity
- menopause sees the suppression removed and therefore increase bone resporption
- imbalance of Bone breakdown and laying down
- therefore bone density decreases
- osteoporosis - fractures are common
- relieved with oestrogen activity
Oestrogen sensitive tissues
- uterus
- shrinkage of myometrium and regression of endometrium
- involution of some breast tissue
- vaginal rugae lost
- changes in skin and bladder
- cervical thinning
Describe the end of reproductive life in men
No obvious event, spermatogenesis continues.
How might meningitis cause precocious puberty?
It can activate the HPG axis, which then starts to secrete GnRH etc
If you are concerned a boy of pubertal age is not going through puberty, what investigations might you undertake?
X-ray of the carpal bones to show size.
Orchidometer - a medical instrument to measure the volume of testes
What does ‘TAGMe’ mean?
Thelarche
Adrenarche
Growth spurt
Menarche
What is the average amount of blood lost during menstruation?
30-45ml
Define: Ammenorhoea Dysmenorrhoea Oligomenorrhoea Menorrhagia
Amennorhoea - absence of periods
Menorrhagia - heavy periods
Dysmenorrhea - painful periods
Oliogomenorrhoea - longer intervals between periods
What is primary amenorrhea?
- Absence of menses by the age of 14, with the absence of secondary sexual characteristics. (SSCs)
- absence of menses by 16 with normal SSCs
