B3 - The menstrual cycle

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How many stages does the menstrual cycle have?
Four
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Why does the menstrual cycle happen?
The lining of the uterus is preparing for a fertilised egg
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What happens during stage one?
The bleeding starts and the uterus lining breaks down and is released
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What happens during stage two?
From day four to fourteen, the lining builds up again ready to receive a fertilised egg
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What happens during stage three?
An egg is released from the ovary at about day fourteen
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What happens during stage four?
The lining is maintained until day twenty eight. If the egg is not fertilised then the lining will break down again and return to stage one
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What is FSH and what does it do?
Follicle stimulating hormone; -Causes the follicle to mature in one of the ovaries -Stimulates oestrogen production
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What does oestrogen do?
-Causes the lining of the uterus to thicken and grow -High levels can stimulate an LH surge
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What is LH and what does it do?
Luteinising hormone; -Stimulates ovulation, the follicle ruptures and the egg is released -Stimulates the remains of the follicle to develop into corpus luteum which secretes progesterone
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What does progesterone do?
-Maintains the lining of the uterus -Prevents production of FSH and LH
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What happens to levels of progesterone if there is a fertilised egg?
The levels will stay high to maintain the lining of the uterus during pregnancy
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What does the placenta supply?
Oxygen, glucose and nutrients
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How can hormones be used in fertility treatments
LH and FSH can be injected into women whose levels are too low for the eggs to mature and stimulates egg release
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Other cards in this set

Card 2

Front

Why does the menstrual cycle happen?

Back

The lining of the uterus is preparing for a fertilised egg

Card 3

Front

What happens during stage one?

Back

Preview of the front of card 3

Card 4

Front

What happens during stage two?

Back

Preview of the front of card 4

Card 5

Front

What happens during stage three?

Back

Preview of the front of card 5
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