Question

explain mechanism of muscle contraction..briefly

Answer 1

MUSCLE CONTRACTION:

Muscle starts to contract when it receives information from motor neurons.
Muscle starts to contract when it receives information from motor neurons. During contraction, I bands are reduced, A bands retain their length. Actin and myosin filaments slide over one another during contraction.

Answer 2

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 secrets on the fibre from the nerve ending.
.The membranes of muscle fibers open up by. the action of acetylcholine.
.The sodium ions enter inside the membrane through this opening.

.The sodium channels also gets opened.
.This initiated action potential inside the membrane.
.The action potentials runs along the muscle fibre.
.Due to this action potential the sarcoplasm releases the calcium ion ca++
.The calcium ions result in attractive forces between actin and myocin filaments of muscles that causes contractions.