This lesson contains 26 slides, with interactive quizzes, text slides and 2 videos.
Lesson duration is: 45 min
Items in this lesson
Paragraph 5.4 The menstrual cycle
Slide 1 - Slide
Welcome to this lesson!
Today, we will be discussing the menstrual cycle of women
This is an important part of understanding how reproduction in humans work
It can be quite difficult, so please note any questions that come up so we can discuss them later!
Slide 2 - Slide
Planning
Lesson goals
Introduction to the paragraph
Videos and explanation
Work on exercises
Slide 3 - Slide
Lesson goals
You can explain when menstruation happens in a female life and what the function is of menstruation
You can explain what happens during the different phases of menstruation
You can explain how hormones influence the menstruation and the female body
You can explain the role of oestrogen, progesterone, FSH and LH in the menstruation
Slide 4 - Slide
Let's start!
Take notes during the lesson in your notebook, this will help you get an overview. Do it at your own speed!
And again: write down any questions that come up
Slide 5 - Slide
Menstruation
Each month, the female body prepares an egg cell to be fertilised
When that egg is not fertilised, the body will get rid of it. That is done through menstruation.
Fertilisation = bevruchting
Slide 6 - Slide
Menstrual cycle
The menstrual cycle is the process that the female sex organs go through each month again; preparing an egg for fertilisation, and getting rid of it when it is not fertilised.
This whole process is regulated by hormones
This cycle generally lasts somewhere between 21 to 35 days, on average it is 28 days (that is why we normally count in months)
Slide 7 - Slide
When do women menstruate?
When girls are born, all their egg cells are already formed in the ovaries
During puberty (between age of 12 and 15), most girls begin to menstruate the first time. Some start even earlier than 12, others only start at 18, which is completely normal.
A woman stops menstruating during the menopause, mostly between the age of 45 and 55 (but again, earlier or later is possible)
The age at which menstruation starts and ends depends on many things, including genetics, health, and diet.
Slide 8 - Slide
Video
In the next slide you will find a short video that gives a good introduction on the menstrual cycle.
Slide 9 - Slide
Slide 10 - Video
The menstrual cycle
Again: the whole cycle generally repeats every 28 days
Menstruation itself is part of this cycle
During the rest of this lesson we will discuss the phases of the cycle, the hormones of the cycle, and the effects of the cycle on the rest of the body
Slide 11 - Slide
Phases of the menstrual cycle
The menstrual cycle contains 3 phases. During these phases changes are happening in three different places:
The ovaries (where the egg cells are)
The uterus (where the fertilised egg cell would grow)
The rest of the body (mainly side effects of the hormones)
Slide 12 - Slide
Phases of the menstrual cycle
The menstrual cycle contains 3 phases:
The menstruation (also called period) - 4 to 6 days
Development of egg cell and making the uterus ready - about 8 days
Release of the egg cell and finishing the uterus - about 14 days
Slide 13 - Slide
Phases
In this image, the menstrual cycle is shown. Try to find the different phases!
This image gives the phases names, we will not use them (just phase 1, 2 and 3)
Slide 14 - Slide
Phase 1: menstruation
The menstrual cycle starts with the menstruation itself. This means that the uterus empties itself completely to prepare for the rest of the month
Menstrual flow: blood and other substances will flow out of the uterus, towards the vagina
This can cause cramps, bloating and other discomfort (generally not pleasant, but necessary)
Slide 15 - Slide
Phase 2: preparing the egg and uterus
In order for fertilisation to happen, we need an egg cell to be ready, and we need the uterus to be ready.
The egg cell develops (grows) under influence of FSH
The uterus starts building a lining on the inside where a fertilised egg cell could nestle under the influence of oestrogen
At the end of phase 2, the egg cell is ready and will come out
You could compare it to making a bed comfortable, because only a mattress is not enough. Add blankets, a pillow, ...
Slide 16 - Slide
Ovulation
The egg cell is ready, and will come out of the ovary to be fertilised (release is caused by LH)
This is what we call ovulation, which happens somewhere around day 15 of the cycle
The ovulation marks the end of phase 2 and starts phase 3
Slide 17 - Slide
Phase 3: release of egg cell and finishing the uterus
The egg cell has come out of the ovary, and is in the oviduct where it waits to be fertilised
This has to happen within 24 hours, otherwise the egg cell will die
The uterus keeps preparing for a fertilisation, so will grow the lining a bit more (caused by progesterone)
Slide 18 - Slide
Phase 3: release of egg cell and finishing the uterus
When the egg is fertilised: pregnancy will happen (paragraph 5.6)
When the egg is not fertilized: the uterus lining will start to break down again, and after a few days we will arrive back to the beginning of the cyle - the menstruation
(Phase 1 again): the uterus lining will flow out of the uterus together with blood and be disposed out of the body
Slide 19 - Slide
That concludes the whole cycle!
This is quite a complicated process, and is actually even more complicated than what we explained now.
You saw that I also included a bit about the hormones already. In the next slide, I have included a video that explains very well what the different hormones do. Please take notes!
You can ignore the part about hormones promoting and stopping each other, that's where it gets a bit difficult
Slide 20 - Slide
Slide 21 - Video
Link the hormone to the function! (and take notes of it when you don't know them)
Finishing the uterus lining
Developing the egg
Development of uterus lining
Causing ovulation
Oestrogen
Progesterone
FSH
LH
Slide 22 - Drag question
Effects on the rest of the body
The menstrual cycle can have some effects on the rest of the body as well
Of course, during menstruation, it can cause cramps, back pain and bloating
It also has influence on: mood, behavior, eating, attraction, ...
It depends on the cycle and on the person how much these things are affected (changes every month)
Slide 23 - Slide
That was it..
This was a very short overview of the menstrual cycle. I can understand that this is quite a difficult topic, which we will repeat a few times to make sure you understand it.
The next slide contains a place where you can ask questions for me to answer!
Your homework is to finish exercise 11-16, and study paragraph 5.5
Slide 24 - Slide
Ask any questions here!
Slide 25 - Open question
Wrapping up
Take some time now to go over your notes and make exercise 11-16