Transcript The Muscular System

The Muscular System
•To
develop understanding of the muscular system
•To understand the role muscles have in movement in the
body
Choose a model
 Work as a team to identify the muscles on
the list provided
 Label your model using the stickers

Extension:
 In your groups, identify exercises that
would benefit each muscle labelled

Starter activity
There are three types of muscle:
 Voluntary
 Involuntary
 Cardiac
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Muscle types
Quick quiz

Muscles work in pairs
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E.g. bicep curl
Which muscles work to create
this movement?
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This is called an antagonistic pair of
muscles
Muscles and Movement
These pairs are always two
muscles that work together
to create movement at joints
 This is because muscles can
only pull.
 One muscle (agonist)
contracts whilst the other muscle
(antagonist) relaxes to cause movement

Antagonistic Muscle Pairs
The biceps and triceps work
together as an antagonistic pair
to move the elbow joint.
To flex the elbow, the biceps
(the agonist) contracts and the
triceps (the antagonist) relaxes.
To extend the elbow, the
actions are reversed so that the
triceps contracts and the biceps
relaxes.
Upper arm muscles
Voluntary muscles (front)
Voluntary muscles (rear)

For each of the sporting movements,
work out which antagonistic muscle
pair creates movement and the type
of movement they create.

E.g. Bicep curl – the bicep muscle
(agonist) contracts and shortens and the
tricep muscle (antagonist) relaxes and
lengthens to cause flexion at the elbow
Activity!
Sporting movements:
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Star jump (arm movement)
Kicking a football
Sit up
Choose your own sporting movement
Extension: Name the type of joint in the
action and the bones that make up that joint
Activity!
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Star Jump (arm movement only):
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Agonist – Deltoid contracts and shortens
Antagonist – Lattisimus Dorsi relaxes and
lengthens
Causes abduction at the shoulder
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Extension:
Ball & socket joint
Humerus, clavicle (collarbone), scapula
(shoulder blade)
Answers!
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Kicking a football:
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Agonist – Quadricep contracts and shortens
Antagonist – Hamstring relaxes and
lengthens
Causes extension at the knee
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Extension:
Hinge joint
Femur, tibia (shin bone)
Answers!
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Sit up:
Agonist – Abdominals contract and
shorten
 Antagonist – Erector Spinae relaxes and
lengthens
 Causes flexion at the waist/upper hip
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Answers!
1.
This picture shows part of the muscular system.
a) Name muscles a–e
(5)
Janine exercises her deltoids by lifting
heavy weights. She raises her arms out
to the sides until her hands are level with
her shoulders.
b) What type of movement is
occurring at the shoulder?
2.
b
a
c
d
e
(1)
Explain what is meant by an antagonistic pair and give one
example
(5)
Exam-style questions
One person will be randomly chosen to sit
in the hot seat
 They will answer 10 questions
 After each answer, write a tick if you
agree with it or a cross (x) if you don’t!

In the Hot Seat...
Effects of Exercise on
the Muscular System
To develop your understanding of longterm and short-term effects of exercise on
the muscular system
•
Activity
In your pairs, draw two columns, like
below
 List as many effects of exercise on the
Muscular System as possible

Short Term Effects Long Term Effects
of Exercise
of Exercise
Increased energy demands
 Lactic acid build up
 Muscle fatigue
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These are all body responses
Short Term Effects of Exercise
on the Muscular System
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Also an immediate effect of exercise
Two types:
 Isometric Muscle Contractions
 Isotonic Muscle Contractions
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Muscle Contractions
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No muscle movement
Muscle neither contracts or relaxes
This type of muscle contraction is used for
static strength
Think of examples of when this could be
used
 Rugby scrum
 Handstand in gymnastics
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Isometric Muscle Contractions
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Muscles work in pairs to contract and relax to
cause movement
Used for explosive and dynamic actions
This muscle contraction is normally used to
produce speed and power
Think of examples when this muscle
contraction is used
Tennis serve
Jumping for the ball in football
Isotonic Muscle Contractions
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There are four stations around the room
Working in your fours, move to the station
closest to you
Try out the activity
When you get there, find the following and
write in your books:
The name of the activity
Is it an Isometric/Isotonic muscle
contraction?
Why?
Which muscles are used?
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You have three minutes at each station!
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Activity!
Isometric muscle contraction
 There is no movement in any muscle –
they all stay the same length
 Main muscles involved: quadriceps,
hamstrings
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Station 1: Wall Stand
Isotonic muscle contraction
 The muscles are working in antagonistic
pairs to contract and relax the muscles to
cause movement
 Main muscles involved: quadriceps,
hamstrings, gluteals, gastrocnemius
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Station 2: Burpee
Isotonic muscle contraction
 The muscles are working in antagonistic
pairs to contract and relax the muscles to
cause movement
 Main muscles involved: gluteals, deltoid,
lattisimus dorsi, pectorals
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Station 3: Star Jump
Isometric muscle contraction
 There is no movement in any muscle –
they all stay the same length
 Main muscles involved: biceps, triceps,
quadriceps, hamstrings
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Station 4: Tug of War
Increased muscular strength
 Muscle hypertrophy
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Muscle hypertrophy is the increase in the
size of the muscle
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These are body adaptations
Long Term Effects of Exercise on
the Muscular System
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What is the other effect of exercise on the
muscular system?
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It is a negative effect of exercise
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Muscle strain
Where the muscle fibre tears
 Overstretching
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Injury
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Can’t participate in sport whilst injured
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Leads to muscle wastage
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This is called muscle atrophy
Effects of Injuries on the Muscular
System
R
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Treatment of Muscle Injuries
Voluntary muscles