The Menstrual Cycle
L.O: To know how hormones
are used to control the
menstrual cycle
Complete this table
Process
Adrenalin increasing
heart rate and sugar
in the blood
Type of response
(nerve/hormone)
Target organ
Heart and liver
Insulin controlling
sugar
Touching a hot
tripod
Testosterone in men
Male reproductive
organs
Airzooka and
blinking
ADH (anti-diuretic
hormone)
kidneys
Oestrogen
Ovaries, uterus,
pituitary gland
What are hormones?
The Endocrine System
Hormones
• Hormones are used to send
information around the body
• They work more slowly than
nerves
• They are secreted by glands (e.g.
the pituitary gland
• They travel in the blood
• They go to all organs but usually
only affect target organs e.g.
ovaries and pancreas
Why is the menstrual cycle
important?
• Matures the ovum for ovulation
• Controls the release of the ovum
(ovulation)
• Thickens the uterus to receive an ovum
• Maintains the lining of the uterus in
pregnancy
• Induces menstruation ‘a period’ if the
ovum is not fertilized
Endocrine glands
pituitary
gland
The pituitary gland produces several
specific hormones in females:
follicle stimulating hormone (FSH)
luteinizing hormone (LH)
The ovaries produce oestrogen
and progesterone
The menstrual cycle – can
we model this?
Step 1: FSH
produced by the
pituitary gland
causes both an egg
to mature and the
ovaries to start
producing oestrogen
Step 2: The rising levels of
oestrogen cause the pituitary
gland to stop producing FSH
and produce LH instead
Step 3: LH
stimulates the
release of the
mature egg in
the middle of
the menstrual
cycle
3 hormones are involved in the menstrual cycle: oestrogen, LH and
FSH. Here’s how:
14/03/2016
Worksheet
FSH
• FSH (follicle stimulating hormone)
• Secreted by the pituitary gland
• Causes eggs to mature in the
ovaries
• Stimulates the ovaries to produce
oestrogen
Oestrogen
• Secreted by the ovaries
• Stimulates the lining to be made
• Stops productions of FSH so no
more eggs mature
• Causes the release of LH which
causes an ovum to be released
(ovulation)
Progesterone
• A high level of Progesterone
maintains the lining of the uterus
• When the level of progesterone
falls the uterus lining breaks down
resulting in menstruation (a
period)
1.
2.
3.
4.
5.
6.
Quick Quiz
Give 2 differences between the way
information travels by nerves and hormones
Give 2 reasons the menstrual cycle is
important
Which hormone is responsible for
maintaining the lining of the uterus?
Which hormone causes the ovum to mature?
Which hormone is associated with the
release of an ovum (ovulation)?
On which day is a woman most likely to get
pregnant?
• http://www.nelsonthornes.com/4u
resources/resources/Biology/AQA/i
nteractives/B1a1/Menstrual_cycle_animation/inter
face.swf