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The Sliding-Filament Theory

Gross and Microscopic Structure of Skeletal Muscle Including Ultrastructure of a Myofibril

Roles of Actin, Myosin, Calcium Ions and ATP in Myofibril Contraction

Striations In Skeletal Muscle Are Caused By Filaments Of Two Protein Actin And Myosin

Structure Of Actin And Myosin Filament

Neuromuscular Junction

Muscles As Effectors

Role of ATP and Phosphocreatine in Providing the Energy Supply During Muscle Contraction

Stimulation Of Muscle Fibres By The Nervous System

Cycle Of Events During Contraction Of A Myofibril

Energy In Active Muscle Cells

Table 16-9-1: Structure, location and general properties of slow and fast skeletal muscle fibres
Feature Fast muscle Slow muscle
Role in body - Rapid, powerful movements - Short-lasting - Slow movement - Long-lasting
Diameter of fibres Large Small
Capillaries Few Many
Sarcoplasmic reticulum High Low
Mitochondria Few Many (ETC, Krebs cycle)
Speed of contraction Fast Slow
Rate of pumping Ca2+ High Slower
ATPase activity High, split ATP quickly Low, split ATP slowly
Respiration Anaerobic Aerobic
Glycogen content High Low
Myoglobin content Low High
Resistance to fatigue Low High
LOCATION Arms and legs (running and throwing) Back and neck (postural muscles)