Menstrual cycle

• Menstrual cycle has 4 stages
• Stage 1 is when the uterus breaks down for about 4 days
• Stage 2 is when the uterus lining builds back up again during day 4-14, into a thick spongey layer ready to receive a fertilised egg
• Stage 3 is when an egg develops and is released from the ovary at day 14
• Day 14 is day of ovulation
• Stage 4 s when the wall is then maintained until day 28, if not fertilised then the lining breaks down and the cycle repeats
• The menstrual cycle is controlled by 4 hormones - FSH, LH, Progesterone, Oestrogen
• FSH stands for follicle stimulating hormone
• FSH produced by the pituitary gland
• FSH causes the egg to mature and stimulates the ovaries to produce oestrogen
• Oestrogen is produced in the ovaries
• Oestrogen causes the lining of the uterus to grow and stimulates release of LH and inhibits the release of FSH
• LH stands for luteinising hormone
• LH is produce by the pituitary gland
• LH causes release of egg in ovulation
• Progesterone is produced in the ovaries by remains of follicle after ovulation
• Progestrerone maintains lining of the uterus during second half of the cycle, when levels fall= lining breaks down
• Progesterone inhibits the release of FSH and LH from the pituitary gland
• You can use oestrogen to prevent the release of an egg - form of contraception as if levels remain high it inhibits the release of FSH, egg production and development stop
• Progesterone can also reduce fertility by stimulating the production of thick mucous which stops sperm getting though
• Combined contraceptive pill is made up of oestrogen and progesterone
• Combined contraceptive pill is 99% effective at pregnancy prevention but has side effects and it doesn't stop STIs
• Progesterone only pill has fewer side effects and is just as effective
• Other contaceptives include - patch, injection, implant and IUD
• Patch is stuck to the skin and lasts 1 week, contains oestrogen and progesterone
• Implant is inserted under skin of arm, releases a continuous amount of progesterone, stopping the ovaries releasing eggs. Can last 3 years. Makes it hard for a sperm to swim and hard for fertilised egg to implant in the uterus
• Injection contains progesterone and lasts 2-3 months
• IUD is a T shaped device that's inserted in the uterus and kills sperm and prevents implantation of fertilised egg
• Plastic IUDs release progesterone
• Copper IUDs stop sperm surviving
• Barriers to stop sperm and egg meeting include condoms, female condoms, diaphragm and spermicide
• Condoms are the only thing that will protect against STIs
• Diaphragm is a shallow plastic cup that fits over cervix but it must be used with a spermicide
• A spermicide disables or kills sperm, can be used alone but it's only 70-80% effective
• To avoid pregnancy completely the only options are sterilisation, abstinence or natural methods
• Natural methods is avoiding intercourse on days woman is most fertile but it isn't very effective
• Abstinence is just not having intercourse
• Sterilisation is cutting or tying fallopian tubes or sperm ducts, it's permenant but there's a small chance they'll reconnect
• Hormones can be used to increase fertility
• Some womens' FSH levels are too low to cause eggs to mature so they can't get pregnant