Download 5.3 unit 2 theme 1 Hormones

Hormones
5.3 Unit 2, Theme 1, My Family
Learning objectives
• What are hormones?
• What do hormones do?
• What is homeostatis?
Automatic systems
• The body has automatic
systems
• Constantly monitor and control
it’s internal environment
• E.g. right temperature
• Right amount sugar in your
blood stream
hormones
• Both temperature and blood-sugar level are
controlled by hormones
hormones
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Chemical messengers
Travel round your body
Made in glands
Secreted into blood
Carried round body
hormones
• Cause a response in specific cells found in
target organs
Nerves and hormones
nerves
hormones
Speed of response
Very fast
slower
Length of response
Short acting
Longer acting
Area targeted
Very precise area
Larger area
Time of reaction
immediate
Longer term
question
• Where are hormones produced in the body?
question
• What role do hormones play in the body?
Produce adrenaline
Involved in flight or
fight reaction that
occurs in response to
danger
Produce testosterone –
causes sperm
production, hair
growth, shoulders to
widen
Produces insulin and
glucogen – controls
blood sugar level
Produce oestrogen
–causes eggs to
mature, pubic hair
to grow, breasts to
enlarge
question
• Name two hormones that are responsible for
the changes take place in puberty
• http://www.bbc.co.uk/education/clips/ztt9jxs
homeostasis
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What is homeostasis
Keeping the conditions in your body constant
Essential for the body to function normally
Is maintained by the nervous system and
hormones ,
enzymes
• Require exactly the right conditions to work
effectively
• Some enzymes build molecules that are
needed by the body for growth
• Others break down molecules – to digest food
for example
• Slight changes can prevent this from working
question
• What does homeostasis mean?
• http://www.bbc.co.uk/schools/gcsebitesize/sc
ience/aqa_pre_2011/human/hormonesact.sht
ml
Which body systems are controlled by
homeostasis?
• Body temperature
• Controlled by changes in the skin
Which body systems are controlled by
homeostasis?
• Blood glucose
(sugar)
concentrations
• Controlled by
hormones in
the liver and
pancreas
Which body systems are controlled by
homeostasis?
• Blood carbon dioxide concentrations
• Controlled by lungs
Which body systems are controlled by
homeostasis?
• Body water
concentrations
• Controlled by
the kidneys
Key points
• Hormones are secreted by glands
• They are chemical messengers that travel
around your body in blood
• Hormones control body processes that need
constant adjustment to maintain a constant
internal environment
• Homeostasis is the maintenance of a constant
internal environment
A bit of Brian Cox
• http://www.bbc.co.uk/education/clips/zgt87t
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