Welcome to my channel power of knowledge academy. In this video you will learn about Mechanism of muscle contraction.
General Mechanism of Skeletal Muscle Contraction
Skeletal muscle contraction initiation and execution occur in the following steps.
An action potential (AP) travels along a motor nerve to its endings on muscle fibers.
At each motor nerve ending, the nerve secretes acetylcholine (ACh).
ACh acts locally on the muscle fiber membrane to open ACh-gated cation channels.
The opening of ACh-gated channels allows large quantities of sodium (Na) ions to diffuse to the interior of the muscle fiber membrane.
This action causes a local depolarization, leading to the opening of voltage-gated sodium (Na) channels, which initiates an AP at the membrane.
The AP depolarizes the muscle membrane, causing the sarcoplasmic reticulum (SR) to release large quantities of Ca ions stored within the reticulum.
The Ca ions produce attractive forces to act between actin and myosin filaments, causing them to slide alongside each other leading to the contractile process.
After a fraction of a second, the Ca ions are pumped back into the SR by a Ca-membrane pump and remain stored in the SR until a new muscle AP occurs.
The removal of Ca ions from the myofibrils causes muscle contraction to cease.
Some main concepts that you will learn in this video are
How Muscle Contracts,
Control of muscle Contraction,
Energy of Muscle contraction,
Structure of Thin and Thick Filament,
Stimulation Muscle to contract,
Providing Energy for muscle contraction,
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