The menstrual cycle (coordination and control) * Flashcards
Fill the gaps:
the average cycle lasts __ days
between day _ and day _ menstruation occurs
on day __ ovulation occurs
the average cycle lasts 25 days
between day 1 and day 7 menstruation occurs
on day 14 ovulation occurs
What does FSH do?
causes a follicle to mature in one of the ovaries
stimulates oestrogen production in the ovaries
Where is FSH released from?
the pituitary gland
What does oestrogen do?
causes the uterine lining to thicken
stimulates the release of LH
Where is oestrogen released from?
the ovaries
What does LH do?
causes ovulation (at around 14 days)
stimulates the follicle remains to develop into the corpus luteum
Where is LH released from?
the pituitary gland
What does progesterone do?
maintains the lining of the uterus
inhibits FSH and LH
Where is progesterone released from?
the corpus luteum
What is the order that the hormones are released in?
FSH –> oestrogen –> LH –> progesterone
What is infertility?
when some men/women find it difficult to conceive
What are potential reason for infertility? (4 points)
- low sperm count in males
- limited or no egg production in females
- uterus being hostile so fertilised egg cannot implant
- low levels of FSH or LH
What does clomifene do?
causes the pituitary gland to release more FSH and LH
What are the 5 steps of IVF treatment?
1) FSH and LH given to mature the eggs
2) eggs are removed from the ovaries
3) mix eggs with sperm in petri dish to fertilise
4) leave for 24hrs to grow into an embryo in a lab incubator
5) once embryos have grown, one or two are transferred to the uterus
