Role of the muscular system

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Role of the muscular system

• GCSE

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Muscles and Movement
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Aims

• Know the role of the muscular system.
• Understand the particular movements that various
  muscles allow.
• Know the major movements specific muscles are
  responsible for.

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Recap Quiz...

• What is the agonist muscle?
• What is the antagonist muscle?
• Identify one characteristic of CARDIAC muscle.
• What is the insertion of a muscle?
• Are skeletal muscles voluntary or involuntary?

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Muscles and Movement

• Do muscles make up 20, 40 or 60 of of total
  body mass?
• Muscles also allow us to move the body, stabilise
  joints, protects and keeps vital organs in place
  plus gives us our shape!

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Muscle movement categories
Movement Definition
Flexors the muscles that bend a limb at a joint by contracting
Extensors the muscles that work with and against the flexors and that straighten a limb at a joint by contracting.
Adductors the muscles that move a limb towards the body.
Abductors The paired muscles for adductors, which move a limb away from the body.
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Muscle contractions
Type of contraction Explanation
Isotonic contractions These can be CONCENTRIC or ECCENTRIC. Concentric muscle shortens(muscle bulges e.g. bicep) Eccentric muscle gradually lengthens and returns to normal shape/length.
Isometric contractions No actual movement or limb or joint, because muscles work to keep joint stable.
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Task...

• Place your left arm around your right forearm
  with right arm out straight. Clench right fist
  and you will feel the isometric contraction in
  forearm.

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Major muscles movement functions
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Biceps and triceps

• Mainly involved in any movement of the arms,
  especially at elbow, including any throw e.g.
  javelin, ball or smash in tennis, badminton or
  volleyball.

Which is the flexor and which is the extensor?
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Hamstrings and quadriceps

• Mainly involved in any movement of the legs,
  especially kicking, e.g. a football, as well as
  running movements.

Which is the flexor and which is the extensor?
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Abdominals

• Allow movement around stomach and waist.
  Important for keeping body straight and upright.
  Also for exercises such as sit-ups.

What type of contraction do the abdominals do in
a sit-up?
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Pectorals

• Allow the arm to be raised at the shoulders, so
  involved in tennis drive, shot putt and swimming
  strokes.

What type of contraction do the pectorals do in
the downward part of the butterfly stroke?
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Gastrocnemius

• Involved in initial movement of the legs,
  specifically running and take off for a jump.

Can you perform an eccentric contraction with the
gastrocnemius muscle? Try it!
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Question time

• Create a 4 mark question and answer.
• Create a specific sport and movement that has to
  be analysed in relation to
• Agonist/antagonist muscles,
• Types of muscle contraction,
• Flexors, extensors, adductors abductors,
• Origin and insertion.