Menstrual Cycle
05 December 2023
Explain how a sperm cell is
adapted to its function
Describe continuous
variation, and give an
example
LAST LESSON
LAST WEEK
Describe the role of bone
marrow in the body
Describe what the reactivity
series is
LAST YEAR
LAST TOPIC
Challenge: Identify the type of graph you would draw for
continuous and discontinuous variation
Menstrual Cycle
05 December 2023
Explain the events of
the menstrual cycle
and how the
menstrual cycle links
with pregnancy
Fertilisation,
Menstruation, Cycle,
Hormone,
Oestrogen,
Progesterone, FSH,
LH
Define fertilisation
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
Menstrual Cycle
05 December 2023
List all the changes that occur in males
and females during puberty.
Female
Male
Menstrual Cycle
05 December 2023
Fertilisation
What is fertilization?
•
•
Consider what the image above is showing you
Why is it important?
Fertilisation 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
Menstrual Cycle
05 December 2023
The menstrual cycle
• What
changes?
• Why does it
change?
• What causes it
to change?
Menstrual Cycle
The menstrual cycle is
the body’s way of
preparing for
pregnancy.
It only happens in
females.
It is controlled by
chemicals called
hormones.
05 December 2023
Several hormones are involved in
the menstrual cycle of a woman:
• follicle stimulating hormone
(FSH) causes the maturation of
an egg in the ovary.
• luteinising hormone
(LH) stimulates the release of
the egg.
• oestrogen is involved in
repairing and thickening the
uterus lining
• Progesterone maintains the
uterus lining
FSH is secreted by the
pituitary gland. It makes
eggs mature and
stimulates the ovary to
produce oestrogen.
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
The level of oestrogen
rises. This inhibits the
production of more FSH
and stimulates the build up
of the lining of the uterus proliferation
Uterus lining
breaks down menstruation
Lining of uterus
builds up
Lining
maintained
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.
4 hormones involved:
•
FSH
•
Oestrogen
•
LH
•
Progesterone
The Menstrual Cycle
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
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2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Cycle starts
again
Menstrual Cycle
Label the key events on this menstrual cycle timeline
05 December 2023
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.
Menstrual Cycle
05 December 2023
Todays
Lesson
Describe the process of menstruation
Last
Lesson
Recall the key components of the female
reproductive system
Last Last
Lesson
Explain the importance of adaptations