The Menstrual Cycle Dave Crowley, 2007

Menstrual Cycle To know why the menstrual cycle is important Wednesday, April 19, 2017 Menstrual Cycle To know why the menstrual cycle is important

Wordsearch Find as many words associated with fertilisation as possible - use different colours between words associated with the male / female systems You have five minutes, good luck! Bladder Cervix Egg cell Oviduct Sex cell Ovary Penis Scrotum Sperm cell Sperm duct Testis Urethra Uterus Vagina

Menstrual Cycle The female reproductive system includes a cycle of events called the menstrual cycle It lasts about 28 days (but it can be slightly more or less than this) It is controlled by a series of sex hormones (produced in the brain and ovaries) A female must have a menstrual cycle - for fertilisation to occur she needs to release her sex cells (eggs) and be prepared for pregnancy - this occurs during the menstrual cycle

Menstrual Cycle The menstrual cycle begins at day 1, when bleeding from the vagina begins. This is caused by the loss of the uterus lining (with some blood) - this is known as menstruation, or having a period (lasting 3-7 days) By around day 5 menstruation stops. The lining of the uterus begins to re-grow, and an egg cell starts to mature in one of the ovaries Around day 14 the mature egg cell is released from the ovary. This is called ovulation - the egg cell travels down the oviduct towards the uterus If the egg cell does not meet with a sperm cell (no fertilisation) then the lining of the uterus begins to break down again, and the cycle repeats BUT - if the egg cell meets and joins with a sperm cell (fertilisation) then it attaches to the lining of the uterus and the female becomes preganant - at this point the cycle stops

Timeline Day 1 - menstrual cycle and menstruation (period) begins (lasts 3-7 days) Day 3-7 - menstruation (period) stops Day 14 - an egg cell is released from one of the ovaries (ovulation) Day 28 - if the egg has not been fertilised (by a sperm), the cycle repeats

Pregnancy If an egg cell and sperm cell meet, and there is successful fertilisation, the body will detect this, and the soft lining of the uterus not break down (the female will have no more menstruations / periods) The embryo will then attach to the uterus lining, where it will develop into a foetus (and in a human, this development will last for around nine months until birth) During pregnancy, the uterus lining becomes much thicker as it supplies the embryo with the materials it needs to develop and grow. It will not break down during pregnancy (if this were to happen the foetus would not be able to develop and grow, and would die)

Menstrual Cycle Complete the menstrual cycle worksheet, sticking all the sections into your book - use colouring pencils to make it stand out When completed, answer the questions

Menstrual Cycle Menstruation (period) The lining of the uterus breaks apart and passes out of the vagina, with blood Most fertile time The egg cell is swept along the oviduct towards the uterus Ovulation The egg cell is released from the ovary (~ day 14) Egg maturation The egg cell starts to mature in the ovary. The uterus lining builds up If an egg is fertilised between days 15-28, the menstrual cycle will stop Fertile means the female has the ability to become pregnant (greatest chance of conception) Probably ~ 28 days later: 4th December (although this can be a few days before / after) Ext: Anxiety of not knowing exactly what will happen when her body begins to change

Uterus Lining You must also be aware of how the uterus lining changes during the menstrual cycle If fertilisation occurs the soft lining of the uterus will feed the foetus - it is replaced each cycle to ensure it can do this, however once fertilisation has been detected it remains thick

Uterus Lining Complete the uterus lining worksheet, writing in the labels of how the lining changes during the menstrual cycle Then complete the sentences, and make sure everything is stuck in your book!

Uterus Lining The lining breaks down The lining gets thicker An egg is released The lining stays thick Egg cells are released from the ovaries. The time when they are released is called ovulation. If the egg cell meets a sperm cell it will be fertilised. If it does not, it will die. The time when the uterus lining breaks apart is called menstruation. Another term for this is ‘having a period’. During this time the uterus lining and a little blood passes out of the vagina.

Hormones The menstrual cycle is controlled by hormones - released from the female’s brain and her ovaries These hormones are oestrogen; progesterone; luteinising hormone (LH) and follicle stimulating hormone (FSH) - don’t worry about learning their names!

Questions Answer the following in full sentences: - How long does it take to complete one complete cycle of the menstrual cycle? What happens during menstruation (a period)? How long does menstruation (a period) last? What happens about 14 days after menstruation starts? Why does the soft uterus lining have to become thicker? How might a woman tell that she is pregnant?

Answers A complete cycle takes around 28 days During menstruation (a period) the uterus lining is broken down and passes out of the vagina (along with some blood) Menstruation (the period phase) lasts between 3-7 days After about 14 days after the menstural cycle began the egg cell (ova) is released from the ovaries. It passes down the oviduct, towards the uterus The soft uterus lining supplies the foetus with all it needs to develop (i.e. its food) If a woman stops having her period then she may well be pregnant (although she should check with her doctor to make sure)