Summary of the Sliding Filament Theory Steps
The sliding filament theory of muscle contraction involves the steps:
- Resting State: Actin and myosin filaments overlap only slightly and muscle fibers are relaxed.
- Excitation of the nerve: A nerve impulse stimulates the muscle fiber. It causes the release of calcium ions from the sarcoplasmic reticulum into the sarcoplasm.
- Cross-Bridge Formation: Calcium ions bind to troponin, causing tropomyosin to move. It expose the myosin-binding sites on actin. Myosin heads then bind to these sites and forms the cross-bridges.
- Role of ATP: The ATP molecule is hydrolyzed and causes the myosin head to pivot. It pull actin filaments towards the center of the sarcomere.
- Repeat: The cycle continues as long as calcium ions are present and ATP is available, resulting in the shortening of sarcomeres and muscle contraction.
Sliding Filament Theory
The sliding filament theory explains how muscle fibres contract. The sliding filament theory can be best explained as how muscles contract by the interaction of actin and myosin filaments sliding past each other within muscle cells. The process requires ATP for energy.
The sliding filament theory was proposed in 1954 by Andrew Huxley and Rolf Niedergerke. In this article, we will study the sliding filament theory of muscle contraction notes in detail.
Table of Content
- What is Sliding Filament Theory?
- What is Sarcomere in Muscle?
- Sliding Filament Theory of Muscle Contraction
- Sliding Filament Theory Diagram
- Summary of the Sliding Filament Theory Steps
- How Does Muscle Contraction Occur?
- Importance of Sliding Filament Theory