Question

what are the mechanism of muscle contraction?

Answer 1

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.