repro 3.1- puberty and the menopause Flashcards
What are primary sexual characteristics?
internal and external genitalia, established before birth, but immature.
when do secondary sexual characteristics develop?
The changes that occur during puberty
Give examples of secondary sexual characterstics of the female
-thelarche (breast development)
-Menarche (first period)
-growth spurt
puberache- axillae and pubic hair
When do girls experience puberty?
8-13
Give examples of male secondary sexual characteristics.
testicular growth
growth spurt
deepening of voice
puberache
When do boys experience puberty?
9-14 years
What’s the first change to happen in females and males during puberty?
females- breast bud development
males- growth of the testicles
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).
What is required for puberty to happen?
Rise in GnRH levels, causing a rise in FSH and LH levels.
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)
What does higher androgen levels cause?
-pubic and axillary hair growth
What does the rise in oestrogen cause (characteristic wise)
breast development (breasts have oestrogen receptors, which is what allows for cell growth)
What is the growth spurt caused by?
growth hormone, increased metabolic rate, increased androgens.
What is the critical weight needed for puberty to occur?
47kg.
Why might puberty be occuring earlier and earlier?
increased nutritional status, larger people,