1.5.5
Slow & Fast Twitch Fibres
Slow and Fast Twitch Fibres
Slow and Fast Twitch Fibres
There are two types of skeletal muscle fibres: slow and fast twitch fibres. They differ in their location, structure and properties.


Location
Location
- Slow twitch fibres -
- Found in muscles used for posture such as the back and neck.
- Fast twitch fibres -
- Found mainly in muscles such as the arms and legs.


Adaption to function
Adaption to function
- Slow twitch fibres -
- Adapted for endurance and slow movement over long periods of time.
- Muscle fibres are long and thin.
- The muscles fatigue slowly and contract slowly.
- Fast twitch fibres -
- Adapted for fast or strong movement over short periods of time.
- Muscle fibres are short and wide.
- The muscles fatigue quickly and contract quickly.


Energy source
Energy source
- Slow twitch fibres -
- Rely on energy released through aerobic respiration.
- Fast twitch fibres -
- Rely on energy released through anaerobic respiration.


Cell structure
Cell structure
- Slow twitch fibres -
- Lots of mitochondria to maintain aerobic respiration.
- Lots of capillaries to supply muscle fibres with oxygen.
- Low levels of glycogen.
- Low levels of phosphocreatine.
- Large stores of myoglobin (pigment that stores oxygen), so appear reddish.
- Less sarcoplasmic reticulum (contains calcium ions).


Cell structure (cont'd)
Cell structure (cont'd)
- Fast twitch fibres -
- Fewer mitochondria.
- Fewer capillaries.
- High levels of glycogen.
- High levels of phosphocreatine.
- Small stores of myoglobin.
- More sarcoplasmic reticulum.
1Principles of Science I
1.1Structure & Bonding
1.1.1Atomic Model
1.1.2Electron Shells, Sub-Shells & Orbitals
1.1.3Ionic Bonding
1.1.4Representing Ionic Bonds
1.1.5Covalent Bonding
1.1.6Representing Covalent Bonds
1.1.7Metallic Bonding
1.1.8Intermolecular Forces
1.1.9Intermolecular Forces 2
1.1.10End of Topic Test - Bonding
1.1.11Relative Masses
1.1.12The Mole
1.1.13Molar Calculations
1.1.14Molar Calculations 2
1.1.15Empirical & Molecular Formulae
1.1.16Balanced Equations
1.1.17Percentage Yield
1.1.18End of Topic Test - Amount of Substance
1.2Properties of Substances
1.2.1The Periodic Table
1.2.2Ionisation Energy
1.2.3Factors Affecting Ionisation Energies
1.2.4Trends of Ionisation
1.2.5Trends in the Periodic Table
1.2.6Polarity
1.2.7Metals & Non-Metals
1.2.8Alkali Metals
1.2.9Alkaline Earth Metals
1.2.10Reactivity of Alkaline Earth Metals
1.2.11Redox
1.2.12Transition Metals
1.2.13Redox Reactions of Transition Metals
1.3Cell Structure & Function
1.4Cell Specialisation
1.5Tissue Structure & Function
1.5.1Human Gas Exchange
1.5.2Blood Vessels
1.5.3Atherosclerosis
1.5.4Skeletal Muscle
1.5.5Slow & Fast Twitch Fibres
1.5.6Neurones
1.5.7Speed of Transmission
1.5.8Action Potentials
1.5.9End of Topic Test - Neurones & Action Potentials
1.5.10Synapses
1.5.11Types of Synapse
1.5.12Medical Application
1.5.13End of Topic Test - Synapses
1.5.14Chemical Brain Imbalances
1.5.15Effect of Drugs on the Brain
1.6Working with Waves
1.7Waves in Communication
2Practical Scientific Procedures and Techniques
3Science Investigation Skills
3.1Scientific Processes
3.2Data Handling & Analysis
3.3Enzymes in Action
3.4Diffusion
3.5Plants & Their Environment
3.6Energy Content in Fuels
4Principles of Science II
4.1Extracting Elements
4.2Relating Properties to use of Substances
4.3Organic Chemistry
4.4Energy Changes in Industry
4.5The Circulatory System
4.5.1The Circulatory System
4.5.2Blood Vessels
4.5.3Blood Transfusion & the ABO Rhesus System
4.5.4The Heart
4.5.5The Cardiac Cycle
4.5.6Cardiac Output
4.5.7Coordination of Heart Action
4.5.8Heart Dissection
4.5.9Controlling Heart Rate
4.5.10Electrocardiograms
4.5.11Cardiovascular Disease
4.5.12Investigating Heart Rates
4.6Ventilation & Gas Exchange
4.7Urinary System
4.9Thermal Physics
4.9.1Power & Efficiency
4.9.2Work & Energy
4.9.3Conservation of Energy
4.9.4Pressure
4.9.5First Law of Thermodynamics
4.9.6Second Law of Thermodynamics
4.9.7Heat Engines, Heat Pumps & Refrigerators
4.9.8Non-Flow Processes
4.9.9p-V Diagrams
4.9.10Ideal Gases
4.9.11Ideal Gases 2
4.9.12Thermal Energy Transfer
4.9.13Thermal Energy Transfer Experiments
4.10Materials
5Contemporary Issues in Science
5.1Contemporary Issues in Science
5.2Analysing Scientific Information
Jump to other topics
1Principles of Science I
1.1Structure & Bonding
1.1.1Atomic Model
1.1.2Electron Shells, Sub-Shells & Orbitals
1.1.3Ionic Bonding
1.1.4Representing Ionic Bonds
1.1.5Covalent Bonding
1.1.6Representing Covalent Bonds
1.1.7Metallic Bonding
1.1.8Intermolecular Forces
1.1.9Intermolecular Forces 2
1.1.10End of Topic Test - Bonding
1.1.11Relative Masses
1.1.12The Mole
1.1.13Molar Calculations
1.1.14Molar Calculations 2
1.1.15Empirical & Molecular Formulae
1.1.16Balanced Equations
1.1.17Percentage Yield
1.1.18End of Topic Test - Amount of Substance
1.2Properties of Substances
1.2.1The Periodic Table
1.2.2Ionisation Energy
1.2.3Factors Affecting Ionisation Energies
1.2.4Trends of Ionisation
1.2.5Trends in the Periodic Table
1.2.6Polarity
1.2.7Metals & Non-Metals
1.2.8Alkali Metals
1.2.9Alkaline Earth Metals
1.2.10Reactivity of Alkaline Earth Metals
1.2.11Redox
1.2.12Transition Metals
1.2.13Redox Reactions of Transition Metals
1.3Cell Structure & Function
1.4Cell Specialisation
1.5Tissue Structure & Function
1.5.1Human Gas Exchange
1.5.2Blood Vessels
1.5.3Atherosclerosis
1.5.4Skeletal Muscle
1.5.5Slow & Fast Twitch Fibres
1.5.6Neurones
1.5.7Speed of Transmission
1.5.8Action Potentials
1.5.9End of Topic Test - Neurones & Action Potentials
1.5.10Synapses
1.5.11Types of Synapse
1.5.12Medical Application
1.5.13End of Topic Test - Synapses
1.5.14Chemical Brain Imbalances
1.5.15Effect of Drugs on the Brain
1.6Working with Waves
1.7Waves in Communication
2Practical Scientific Procedures and Techniques
3Science Investigation Skills
3.1Scientific Processes
3.2Data Handling & Analysis
3.3Enzymes in Action
3.4Diffusion
3.5Plants & Their Environment
3.6Energy Content in Fuels
4Principles of Science II
4.1Extracting Elements
4.2Relating Properties to use of Substances
4.3Organic Chemistry
4.4Energy Changes in Industry
4.5The Circulatory System
4.5.1The Circulatory System
4.5.2Blood Vessels
4.5.3Blood Transfusion & the ABO Rhesus System
4.5.4The Heart
4.5.5The Cardiac Cycle
4.5.6Cardiac Output
4.5.7Coordination of Heart Action
4.5.8Heart Dissection
4.5.9Controlling Heart Rate
4.5.10Electrocardiograms
4.5.11Cardiovascular Disease
4.5.12Investigating Heart Rates
4.6Ventilation & Gas Exchange
4.7Urinary System
4.9Thermal Physics
4.9.1Power & Efficiency
4.9.2Work & Energy
4.9.3Conservation of Energy
4.9.4Pressure
4.9.5First Law of Thermodynamics
4.9.6Second Law of Thermodynamics
4.9.7Heat Engines, Heat Pumps & Refrigerators
4.9.8Non-Flow Processes
4.9.9p-V Diagrams
4.9.10Ideal Gases
4.9.11Ideal Gases 2
4.9.12Thermal Energy Transfer
4.9.13Thermal Energy Transfer Experiments
4.10Materials
5Contemporary Issues in Science
5.1Contemporary Issues in Science
5.2Analysing Scientific Information
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