hormones(menstrual cycle)

• why are some people against ivf?

  It often results in unused embryos that are eventually destroyed - unethical because each embryo is a potential human being

  Genetic testing of embryos before implantation raises ethical issues - could lead to the selection of preferred characteristics e.g. gender, eye colour etc
• what are the cons of ivf?

  1) Multiple births can happen if more than one embryo grows into a baby:

  -More dangerous for mother and baby

  -Higher risk of miscarriage and stillbirth

  2) Success rate is low (around 26% success rate in the UK)

  3) Emotional and physical stress for the woman

  -Can have a strong reaction to the hormones e.g abdominal pain, vomiting, dehydration
• what is ivf?

  The egg is fertilised outside the woman's body and then implanted back into her uterus.
• what are the cons of giving fsh and lh to infertile women?

  doesnt always work and can result in twins or triplets sometimes.
• advantages of giving fsh and lh to infertile women?

  helps lots of women get pregnant
• what is sterilisation?

  Involves cutting or tying the fallopian tubes or the sperm duct, it is permanent but there is a very small chance that the tubes will rejoin
• what are the types of contracteptive?

  the pill

  the contraceptive patch

  the contraceptive injection

  IUD

  condom
• what are the disadvantages to the pill?

  its 99% effective so theres till a chance to get pregnant and doesnt stop stds
• What side effects does the pill have?

  headaches and nausea
• what does the pill contain?

  oestrogen and progesterone
• How does progestrone reduce fertility?

  stimulates the prodcution of thick mucus which prevents any sperm getting through to the egg
• how does oestrogen reduce fertility?

  - Oestrogen inhibits FSH production in the pituitary gland, which is the hormone that causes eggs to mature in the ovary and stimulates the release of LH in the pituitary gland, which stimulates ovulation.

  
  

  - Therefore, if oestrogen is taken every day to keep the level of it permanently high, FSH and LH production is inhibited, causing egg maturation and ovulation to cease.
• how does pregnancy?

  sperm reaches the ovulated egg
• what does progesterone do?

  - Produced in the ovaries by the remains of the follicle after ovulation

  - Maintains the lining of the uterus during the second half of the cycle. When the level of progesterone falls, the lining breaks down

  - Inhibits the release of LH and FSH
• what does oestrogen do?

  produced in ovaries.

  causes the lining of the uterus to grow.

  stimulates the release of LH and inhibits release of FSH
• what does LH do?


  Stimulates the release of an egg at day 14
• what does fsh do?

  produced in pituitary gland

  Causes egg to mature and stimulates ovaries to produce oestrogen
• what happens in stage 4 of the menstrual cycle?

  The wall is then maintained for about 14 days until day 28. If no fertilised egg has landed on the uterus wall by day 28, the spongy lining starts to break down and the whole cycle starts again.
• what happens in stage 3 of menstrual cycle?

  An egg develops and is released from the ovary at day 14 - this is called ovulation.
• what happens in stage 2 of the menstrual cycle?

  The uterus lining builds up again, from Day 4 to Day 14, into a thick, spongy layer full of blood vessels, ready to receive a fertilised egg
• what happens in stage 1 of the menstrual cycle

  Day 1: Menstruation starts - uterus lining breaks down for about 4 days
• what is the main reproductive hormone in women?

  oestrogen produced by the ovaries
• what is the main reproductive hormone in men?

  -Testosterone

  - Produced by testes and stimulates sperm production
• What is the menstrual cycle?

  Time period when blood, tissue and unfertilized egg leaves the body