Transcript Muscular System

Muscular System
Principles of Anatomy and Physiology
Learning Outcomes
• Understand the types of muscle
• Understand the function of the muscles
• Know the location of all the major muscles
Types of muscle?
• Skeletal
• Smooth
• Cardiac
Skeletal
• Skeletal or striated muscle, involved in exercise
• -Under conscious control
• Sometimes referred to as voluntary
Smooth
• Smooth muscle, e.g. digestive tract, artery wall
• Under unconscious control
• Sometimes referred to as Involuntary
Cardiac
• Striated and involuntary
• Specialist heart muscle
• Under unconscious control
Muscles
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Muscles work in pairs
Front & back
e.g. biceps & triceps
Prime mover/agonist - the muscle responsible for bringing about the
action
Can you think of an example?
Biceps curl – agonist = biceps
Antagonist - the opposite muscle that relaxes for movement to occur
e.g. biceps curl – antagonist = triceps
Muscles general rules
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Muscles pull
A muscle crosses at least one joint
A muscle contracts along its line of fibre
Muscles work in pairs
Recap before task
**TASK**
• Label the sticky labels with each muscle you need to know
• You have 5 minutes to place the labels correctly on each other
• Mastermind
• Each of you will have one minute in the mastermind chair to
answer as many correct muscle as possible from the flashcards
Muscle Fibre Types
Principles of Anatomy and Physiology
Muscle structure
Muscle structure
Muscle fibre
Myofibril
Myofilament
Slow Twitch Fibres (Type 1)
• Slow twitch fibres are designed for aerobic exercise, using oxygen
to produce a small amount of tension over a long period of time
• They are very resistant to fatigue as the speed of the contraction
is slow
• They have a higher capacity for aerobic respiration
• They are red in colour because of more myoglobin
• Performers in endurance events tend to have a higher percentage
of slow twitch muscle fibres
Fast Twitch Fibres 2a and 2b
• Subdivided in to two types; Fast Oxidative Glycolytic fibres
(F.O.G.) and Fast Twitch Glycolytic (F.T.G.)
• They are both designed for anaerobic capacity, producing high
contractions in a short period of time
• This however means that they have a low resistance to fatigue
• They are white in colour because of low levels of myoglobin
Relative percentages of fast and slow twitch
fibres in a range of sporting activities
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80
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Non Athlete
Distance Runner
Swimmer
Sprinter
Weight Lifter
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Non Athlete
Distance Runner
Swimmer
Type 1
Type 2
Sprinter
Weight Lifter
Fast Oxidative Glycolytic
Fibres (F.O.G.) – Type 2a
• These anaerobic fibres are
more resistant to fatigue that
type 2b
• FOG fibres generate less force
than type 2b fibres though
• Activities such as a 200m swim
or 800m race will rely on type
2a fibres
Fast Twitch Gylcolytic (F.T.G)
– Type 2b
• Type 2b fibres have the
greatest anaerobic capacity
• Generate largest amount of
force of contraction
• Very poor resistance to fatigue
• Expect a Sprinter or Shot
Putter to have large amounts
of FTG fibres
Summary of muscle fibre types
Characteristics
Slow Twitch (Type I)
Fast Oxidative Glycolytic
(Type 2a)
Fast Glycolytic (Type 2b)
Fibre Size
Small
Large
Large
Mitochondria density
High
Low
Lowest
No of capillaries
Large
Moderate
Small
Myoglobin content
High
Moderate
Low
PC stores
Low
High
High
Glycogen stores
Low
High
High
Triglyceride stores
High
Moderate
Low
Speed of contraction (ms)
Slow (110)
Fast (50)
Fastest (<50)
Force of contraction
Low
High
Highest
Resistance to fatigue
High
Low
Lowest
Aerobic capacity
High
Low
Lowest
Anaerobic capacity
Low
High
Highest
Activity suited to
Marathon
1500m
110m Hurdler
Colin Jackson – The Making of Me
• https://youtu.be/j-mHQACvZfc