Muscle fibre types
Slow oxidative type I, fast oxidative-glycolytic IIa and fast glycolytic IIx fibres: properties and sports.
- 14 cards
- 5 topics
- Free
The outline, topic by topic
Each topic is weighted the way the exam weighs it.
- Concepts
- Sort and link
- The numbers
- Scenarios
- Understand
A few cards from the deck
Type I fibres: what is it?
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Slow fibres rich in mitochondria, myoglobin and capillaries, very fatigue-resistant.
They dominate in distance runners.
A biopsy shows many mitochondria, capillaries and much myoglobin. Fibre type?
- Type I
- Type IIx
- Type IIa
- Smooth fibre
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Type I
These are hallmarks of oxidative metabolism, highest in type I fibres; IIa have less, IIx little.
Type IIa fibres: what is it?
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Fast fibres using both oxidation and glycolysis.
They adapt strongly to training.
Why does a sprinter tire quickly at top speed?
- They lack type II fibres
- Their fast fibres produce great force but fatigue fast
- Only type I fibres work
- Their blood runs short of oxygen
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Their fast fibres produce great force but fatigue fast
Power and endurance trade off in the fibre.