Skeletal muscle

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  • Created by: LZ95
  • Created on: 13-05-14 20:47
What is skeletal muscle?
Muscle attached to bone which acts under voluntary, conscious control
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What are individual muscles made up of?
Millions of tiny muscle fibre called myofibrils
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Describe the properties of an actin filament
Thin + consists of two strands twisted around one another.
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Describe the properties of a myosin filament
Thick + consists of long rod-shaped fibres with bulbous heads
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What are the names of the dark and light bands?
Dark bands = anisotropic bands (A-bands), Light bands = isotropic bands (I-bands)
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How come light bands appear lighter and dark bands appear darker?
No overlap between actin and myosin filaments in light bands whereas there is overlap in dark bands.
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What is the H-zone?
Centre of each anisotropic band (lighter section).
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What is a Z line?
Centre of an isotropic band.
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What is the sarcomere?
Space between adjacent Z lines.
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What does tropomyosin do?
Form a fibrous strand around the actin filament.
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What are slow twitch muscles?
Muscles which contract more slowly and provide less powerful contractions over a longer period.
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What type of respiration are slow twitch muscles adapted to?
Aerobic
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Name 4 adaptations of slow twitch muscles which make them suitable for their role.
1. Many mitochondria 2. Rich supply of blood vessels 3. Glycogen supply 4. Large myoglobin store (bright red molecule storing oxygen)
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What are fast twitch muscles?
Muscles which contract more rapidly and produce powerful contractions for a short period.
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Name 3 adaptations of fast twitch muscles which make them suitable for intense exercise.
1. Numerous myosin filaments 2. Many enzymes which are involved in anaerobic respiration 3. Stores phosphocreatine
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What is a neuromuscular junction?
Where a motor neurone meets a skeletal muscle fibre
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Name 3 changes which occur to the sarcomere when a muscle contracts.
1. I-bands become narrower 2. Z-lines move closer together 3. H-zone becomes narrower
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Other cards in this set

Card 2

Front

What are individual muscles made up of?

Back

Millions of tiny muscle fibre called myofibrils

Card 3

Front

Describe the properties of an actin filament

Back

Preview of the front of card 3

Card 4

Front

Describe the properties of a myosin filament

Back

Preview of the front of card 4

Card 5

Front

What are the names of the dark and light bands?

Back

Preview of the front of card 5
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