what are the mechanism of muscle contraction?
Muscle contraction takes place in following steps
- Nerve impulse travels through a motor nerve to its end points on muscle fibers.
- A little amount of acetylcholine (neurotransmitter) is secreted on the fiber from the nerve ending.
- The membranes of muscle fiber open up by the action of acetylcholine.
- The sodium ions enter inside the membrane through this opening.
- The sodium channels also get opened.
- This initiates action potential inside the membrane.
- The action potential runs along the muscle fiber
- Due to this action potential the sarcoplasm releases calcium ions.
- This calcium ions result in attractive forces between actin and myocin filaments of muscles that cause contraction.