Download Hormonal Control of Growth in Animals

Higher Biology
Hormonal Control of Growth in
Animals
Hormonal Control of Growth
By the end of this lesson you should be
able to:
 Know what a hormone is.
 Know the names of 2 hormones produced by the
anterior pituitary gland.
 Describe the role of thyroxine.
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Introduction
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Hormones are chemical messengers.
They are produced in one part of the body
(in tiny quantities) and carried in the blood
to another part of the body where they
have their effect.
Gland produces
hormone
Hormone carried
in blood
Hormone affects
target organ
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Pituitary Hormones
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The anterior lobe of the
pituitary gland is found at the
base of the brain.
It produces many hormones (remember
ADH?).
Two hormones it produces are involved in
growth and development.
i.e. Human Growth Hormone (GH) and
Thyroid Stimulating Hormone (TSH)
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Human Growth Hormone (GH)
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Also known as somatotrophin
Is produced by the anterior pituitary gland
Travels in the blood
Target organs- bones (particularly the long
bones in the arms and legs) and cartilage
Effects- accelerates amino acid transport
into bones and cartilage.
Permits rapid synthesis of tissue proteins
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Human Growth Hormone (GH)
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So causes growth.
The growth spurt in adolescence is due to
increased production of GH.
Human GH animation
Underproduction
Overproduction
Reduction in
overall growth
In adolescence- very long
bones in arms & legs.
In adulthood- large hand,
feet & jaw bones
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Thyroid Stimulating Hormone (TSH)
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Is produced by the anterior pituitary gland
Travels in the blood
Target organs- thyroid gland (in the neck)
Effects- controls growth and activity of
the thyroid gland & produces thyroxine
(another hormone!)
Thyroxine regulates metabolic processes in
the body.
drop in metabolic rate
Lack of TSH
lack of thyroxine
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TSH and Thyroxine
Put the following stages into the correct
order:
Increases
Thyroid
Pituitary
metabolic
gland
gland
rate
thyroxine
TSH
TSH
Pituitary
gland
thyroxine
Increases
metabolic
rate
Thyroid
gland
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Pituitary Hormones
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Insert and complete the “Endocrine
Summary” diagram from your pack into
your notes.
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Practice Questions
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1.
Torrance
TYK pages 249 Q1 and 2
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Hormonal Control of Growth
Can you do it?
 Know what a hormone is.
 Know the names of 2 hormones produced by the
anterior pituitary gland.
 Describe the role of thyroxine.
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