MUSCLES
AND
MOVEMENT
KS3 Biology
By Dr H E Bloomfield
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How our Muscles Work
Muscles work by
C-------ING
(getting shorter and
fatter) and pulling on
bones.
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How our Muscles Work
But once contracted, a
muscle cannot -------again by itself.
So each muscle needs a
partner to pull it longer
again and move the bone
back in the opposite
direction.
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How our Muscles Work
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How our Muscles Work
Two muscles working together in
opposite directions are called
A------------ muscles.
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How our Muscles Work
The BICEPS and
TRICEPS in our arm
are ANTAGONISTIC
muscles. They work as
a pair and in opposite
directions.
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How our Muscles Work
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Bending our Arm
TRICEPS
relaxes
and is
pulled
longer
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BICEPS
contracts
and bends
arm
Straightening our Arm
TRICEPS
contracts
and
straightens
arm
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BICEPS
relaxes and
is pulled
longer
How our Muscles Work
Muscles are
attached to
bones by
strong nonstretchy
TENDONS.
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muscle
tendons
Our Achilles tendon in our heel
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How Arm Muscles Work
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Muscles, bones and joints
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TAKING
THE
STRAIN
How Strong
are your
Muscles?
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1. Put the scales on the bench. Push down with
your fists as hard as you can.
My result is __________ N
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2. Put the scales under the edge of the bench.
Push upwards with your hands as hard as you
can.
My result is __________ N
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3. Try squeezing the scales with your fingers.
My result is __________ N
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4. Hold the scales between your two palms.
Push them together as hard as you can.
My result is __________ N
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WHERE DO MUSCLES
GET THEIR ENERGY
FROM?
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Muscles get energy for contraction
from R---------------+
------
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ENERGY
+ --+
-----
Energy for Muscle Contraction
Glucose
+
Oxygen
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ENERGY
+ --+
-----
Energy for Muscle Contraction
Glucose
+
Oxygen
ENERGY
+ CO2
+
Water
As the process uses oxygen, it is
sometimes called aerobic respiration.
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THE END
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