Flashcards in repro 3.1- puberty and the menopause Deck (35)
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1
What are primary sexual characteristics?
internal and external genitalia, established before birth, but immature.
2
when do secondary sexual characteristics develop?
The changes that occur during puberty
3
Give examples of secondary sexual characterstics of the female
-thelarche (breast development)
-Menarche (first period)
-growth spurt
puberache- axillae and pubic hair
4
When do girls experience puberty?
8-13
5
Give examples of male secondary sexual characteristics.
testicular growth
growth spurt
deepening of voice
puberache
6
When do boys experience puberty?
9-14 years
7
What's the first change to happen in females and males during puberty?
females- breast bud development
males- growth of the testicles
8
Why do males grow taller than females?
Their growth spurt begins later and lasts longer (due to no oestrogen closing the epiphyseal growth plates early).
9
What is required for puberty to happen?
Rise in GnRH levels, causing a rise in FSH and LH levels.
10
What is thought to cause the rise in GnRH levels?
development and maturation of central mechanisms.
Removal of inhibition to the hypothalamus
a critical weight being achieved (47Kg)
11
What does higher androgen levels cause?
-pubic and axillary hair growth
12
What does the rise in oestrogen cause (characteristic wise)
breast development (breasts have oestrogen receptors, which is what allows for cell growth)
13
What is the growth spurt caused by?
growth hormone, increased metabolic rate, increased androgens.
14
What is the critical weight needed for puberty to occur?
47kg.
15
Why might puberty be occuring earlier and earlier?
increased nutritional status, larger people,
16
What is precocious puberty?
puberty that happens 2 SD below mean, so <8 years for girls, <9 years for boys.
17
How can precocious puberty be classified?
true/complete- due to early maturation of the HPG axis.
False/incomplete- ovarian/testicular/arenal secretion of homrones.
18
Give some causes of true precocious puberty
meningitis
pineal cysts
post-infectious encephalitis
primary hypothyroidism.
19
How does primary hypothyroidism lead to precocious puberty
Hormonal mechanism not well understood, may be due to the low levels of thyroid hormones leading to an increase in TRH and GnRH, thus puberty gets started early.
20
Give some caused of false precocious puberty
ovarian cysts
ovarian/testicular tumours
congenital adrenal hyperplasia
21
How would you distinguish between true and false precocious puberty?
Blood tests to look at the GnRH, LH, FSH and androgen levels.
22
What are some main consequences of precocious puberty?
early closure of the epiphyseal growth plates, leading to short stature.
Family/child distress, eg due to bullying
increased risk of sexual abuse.
23
What's the name given to the end of reproductive life for the female?
Climacteric.
24
How can the climacteric be further subdivided?
pre-menopause
menopause
post-menopause
25
When does the pre-menopause happen and what does it involve?
around 40 years old
Shortening of the follicular phase, sometimes menarche will happen without ovulation
Falling oEstrogen levels
increasing FSH and LH levels.
Reduced fertility
26
Why do FSH and LH levels rise?
less oesotrogen is being produced, so there's less negative feedback, so less inhibition of GnRH and therefore LH/FSH.
27
which hormone rises faster, FSH/LH. Why?
FSH, along with less negative feedback due to less oestrogen, there is also less inhibin production so there is a 2 fold reduction in inhibition.
28
When does the menopause happen?
Around age 50.
29
What are some symptoms of the menopause?
itchy
twitchy
sweaty
sleepy
bloated
moody
forgetful
hot flushes
30