L3 Male & Female Reproductive Endocrinology Flashcards
What does the hypothalamus secrete?
gonadotrophin releasing hormone
What does the anterior pituitary secrete?
luteinizing hormone
follicle stimulating hormone
What stimulates the secretion of LH and FSH from the anterior pituitary?
gonadotrophin releasing hormone
What stimulates the secretion of testosterone?
LH
What inhibits the secretion FSH from anterior pituitary?
testosterone from testes via negative feedback
What happens when males go through puberty? (8)
increased aggression and libido
enlargement of the larynx
male pattern pubic hair
maturation of genitalia
muscle development
sperm production
bone growth
acne
What do the ovaries secrete?
oestrogens and progesterone
LH and FSH both act on what?
ovaries and testes
What happens when females go through puberty? (8)
female psyche
fair complexion
breast development
widening of the pelvis
maturation of genitalia
female pattern pubic hair
subcutaneous fat deposition
ovulation and menstruation
FSH acts on testes to cause what?
Sperm production
Sperm production requires?
LH => testosterone
FSH => sperm production
Oestrogens do not affect what?
the foetus
as there is oestrogen from the mother regardless of sex of offspring
If there is no hormone influence?
causes birth of a baby with female anatomy
What do testosterones cause?
birth of a baby with male anatomy
If XY cannot produce testosterones
born with female genitalia
If there is a little bit of testosterone?
may get partial male anatomy
What happens at puberty in males?
massive increase in testosterone
testosterone converted into what to cause bone growth?
oestradiol
In females, LH causes
ovaries to secrete progesterone
when is progesterone most important?
only important during pregnancy
what do oestrogens suppress?
FSH secretion
FSH causes what in females?
oestrogen secretion
GNRH secretion in females is
pulsatile
Slow production of GNRH causes?
FSH secretion
Fast production of GNRH causes?
LH secretion
What happens if a female foetus is exposed to testosterone?
loses pulsatility of GNRH secretion and becomes like a male
What is the average age women start menopause?
52
Why do women go through menopause?
ovaries stop producing oestrogens
you lose negative feedback
therefore LH and FSH secretion goes up
it is an endocrine event
What is the average duration of bleeding during menstrual cycle?
7 days
In first few days
FSH conc rises
Oestrogen conc rises
Oestrogen provided negative feedback causing FSH conc to dip also causing oestrodiol conc to dip too
Day 12 of menstrual cycle
surge in LH
little surge in FSH (accidental)
What is needed for the surge in LH at day 12?
3 days of elevated oestrodiol secretion
What does LH surge cause?
secretion of progesterone and oestrodiol for about 7 days before it starts to tail off at day 28
The first half of the cycle is dominated by?
Oestrodiol
The second half of the cycle is dominated by?
progesterone
Mid cycle there is a tiny increase in?
testosterone
What is the effect of oestrodiol conc dying down to 0/rise in testosterone during the menstrual cycle?
acne
increased sex drive (most fertile period for women)
The last 14 days of the menstrual cycle are said to be?
constant
What causes the ovum to be expelled?
surge in LH day 12-14
When does ovulation occur?
14 days before the first day of bleeding
What effect does oestradiol have on lining?
causes endometrium to thicken
What causes endometrium to enter secretory phase?
progesterone
Any drop in progesterone triggers what?
Collapse of the endometrium
Vasoconstriction in endometrial tissue initiated by?
drop in progesterone
tissue of endometrium starved of blood supply -hypoxic
causes bleeding
blood clots and then is liquified by fibrinolysis
What do the dying cells produce?
Prostaglandins
What do prostaglandins cause?
uterine contraction
period cramps/pain
Which drugs inhibit prostaglandins?
NSAIDs
aspirin good for period pain
Theoretical risk of using aspirin
anti blood clotting
thins blood
could increase blood flow
What effect do oestrogen have on the cervix?
causes it to dilate
peak during ovulation around day 14
What effect does progesterone have on the cervix?
causes it to constrict
Prostaglandins dilate cervix to allow?
menstrual flow
How does progesterone stop sperm/bacteria getting into uterus?
causes mucus to become viscous
How long can the ovum be fertilised for?
1.5-2 days after ovulation
Average lifespan of sperm
2 days
