Menstruation

1. Menstrual Cycle 19 February 2024
Challenge: Identify the type of graph you would draw for
continuous and discontinuous variation
Explain how a sperm cell is
adapted to its function
Describe continuous variation,
and give an example
Describe what the reactivity
series is
Describe the role of bone
marrow in the body
LAST LESSON LAST WEEK
LAST TOPIC
LAST YEAR

2. 19 February 2024
Menstrual Cycle

3. Explain the events of
the menstrual cycle
and how the
menstrual cycle links
with pregnancy
Fertilisation,
Menstruation, Cycle,
Hormone, Oestrogen,
Progesterone, FSH, LH
Define fertilization
Identify key events on a
diagram of the
menstrual cycle
Explain why pregnancy is
more or less likely at certain
stages of the menstrual cycle

4. Menstrual Cycle 19 February 2024
List all the changes that occur in males and
females during puberty.
Female Male

5. Menstrual Cycle 19 February 2024
Fertilisation
What is fertilization?
• Consider what the image above is showing you
• Why is it important?
Fertilization is when a sperm cell joins with an egg cell. It is important
because this is how reproduction occurs in most living things including
humans

6. Menstrual Cycle 19 February 2024
The menstrual cycle
• What changes?
• Why does it
change?
• What causes it
to change?

7. Menstrual Cycle 19 February 2024
The menstrual cycle is
the body’s way of
preparing for
pregnancy.
It only happens in
females.
It is controlled by
chemicals called
hormones.

8. Several hormones are involved in
the menstrual cycle of a woman:
• follicle stimulating hormone
(FSH) causes the maturation of an
egg in the ovary.
• luteinizing hormone
(LH) stimulates the release of the
egg.
• estrogen is involved in repairing
and thickening the uterus lining
• Progesterone maintains the
uterus lining

9. FSH is secreted by the
pituitary gland. It makes
eggs mature and
stimulates the ovary to
produce oestrogen.
Uterus lining
breaks down -
menstruation
Lining of uterus
builds up
Lining
maintained
The level of estrogen rises.
This inhibits the production
of more FSH and stimulates
the build up of the lining of
the uterus - proliferation
LH is secreted by the pituitary
gland. When its level reaches a
peak it stimulates the release of
a mature egg from the ovary -
ovulation
After the egg is released the level
of progesterone rise and
maintains the lining of the uterus
in preparation for the
implantation of the fertilised egg.

10. The Menstrual Cycle
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The main events in the cycle are:
1) Menstruation – uterus lining breaks down, blood and cells are lost.
2) Proliferation – repair of the uterus lining.
3) Ovulation – release of an egg from the ovary – day 14
4 hormones involved:
• FSH
• estrogen
• LH
• Progesterone
Cycle starts
again

11. Menstrual Cycle 19 February 2024
Label the key events on this menstrual cycle timeline State where in the
menstrual cycle pregnancy
is most likely to occur.
Justify your answer
Challenge: Apply
knowledge of the
menstrual cycle to
graphs showing the
hormones involved.

12. Menstrual Cycle 19 February 2024
Todays
Lesson
Last
Lesson
Last Last
Lesson
Describe the process of menstruation
Recall the key components of the female
reproductive system
Explain the importance of adaptations