Reproductive. L1 Flashcards
When does sexual hair appears in females?
~6 months after the breast bud
Age ~10-12
What causes female pubic hair growth?
Exposure of hair follicles to androgen
When does armpit/ axillary hair develops?
~1 year after pubic hair
What hormones stimulate growth in females and males?
Both oestrogen and androgen
Epiphyseal closure( bony ends) is stimulated by oestrogen
What is the age of growth for females and males?
Females ~ 11-12
Males: ~13-15
What is menarche?
1st menstrual bleed
~12-13
When and why does ovulation occur?
after 6-9 months after menarche. because the positive feedback mechanism of oestrogen have not yet developed
Regular ovulatory cycles are established 1-2 years after menarche
What is the order of puberty events in males?
- Change in testes(10-13.5)
- development of pubic hair( 10-15)
- Growth of the penis(11-14.5)
* Spermatogenesis is earlier than ovulation - Height spurt
first signs of puberty in a male
- Leydig cells enlarge and secrete testosterone, giving rise to increase testicular size
- Elongation and enlargement of the penis begins within a year of testicular enlargement.
When does sexual hair growth occur in males?
~ 6 months after the beginning of the testicular enlargement
Axillary hair ~ 18 months later, facial hair later
Spermache
- motile sperm in urine at ~13-14 years
- The first ejaculation occurs soon after
Why did the age of menstruation decreased over the years?
-able to reach a certain body weight and composition earlier
Why did the age of menstruation decreased over the years?
-able to reach a certain body weight and composition earlier
precocious puberty
the appearance of physical & hormonal signs of puberty before:
7 yrs in girls
9 yrs in boys
OFten a GnRH dependant problem, often extreme cases due to a hypothalamic tumour
Delayed puberty
The lack of appearance of the physical and hormonal signs of puberty:
~13 years in girls
~14 years in boys
Occurs when gonadotropin signals from the pituitary are inadequate for sex steroid hormone secretion
Menopause
the consequence of the ovaries running out of follicles, and occurs between 50 and 52 yo. Either no left, or follicles do not respond to stimulation
The last episode of natural mentrstrual bleeding signifies the end of her reproductive life
How many follicles is a woman born with?
6-7 million during fetal development born with 1-2 million steady decline with puberty (~400 000) through to menapause( <1000).
what is premenopause?
the period before cycle become irregular
What is menopausal transition?
4-5 years
irregular menstruation
What is post-menopause?
after the last mestrual bleed
What is post-menopause?
after the last mestrual bleed
Peri-menopause
time between thee start of menopausal transition and ovarian senescense
what is ovarian senescense?
period when ovaries stop producing hormones
postmenopausal oestrogen production
-dramatic reduction in oestrogen production. No longer produce oestrodiol. drop to 1/10th of the total oestrogen production
Most women after menopause solely rely on oestrogen(oerstrone) from adipose tissue.
Ovaries are no longer working
perimenopausal symptoms
oestrogen deprivation -Vasomotor hot flushes night sweats, panic attacks -Genitourinary symptoms vaginal dryness -Bone metabolism osteoporosis -Behavioural/Psychological changes depression, tension, anxiety, mental confusion, loss of libido
Most of these symptoms of the menopause may be prevented or arrested
by oestrogen treatment (known as menopausal hormone therapy).
what endocrine glands are involved in puberty?
hypothalamus ana pituitary
does the reproductive system have the release inhibiting hormones from hypothalamus?
No
What hormone is released from hypothalamus to pituitary?
Gonadotropin releasing hormone(GnRH)
What gonadotropins are produced by gonadotrophs in the anterior pituitary?
FSH( follicle stimulating hormone)
LH( Leutinising hormone)
These hormones act on the gonads
what hormones do gonads produce?
Sex steroid hormones -acts on target tissues
provide negative feedback on hypothalamus and piruitary
what is the function of FSH in female?
acts on the ovaries to stimulate the growth and development of gametes.
what is the function of FSH in males?
acts on the testes to stimulate the production of gametes
