What role does the motor neuro

1. Muscle contraction begins when thenervous system generates a signal . This signal is called as actionpotential , travel through a type of nerve called a motor neuron .At the neuromuscular junction motor neuron reaches a muscle . Achemical called neurotransmitter (acetylcholine) is released at theneuromuscular junction which binds with the receptor on the outsideof the muscle fibre. This start the chemical reaction within themuscle .

2. Sarcoplamic reticulum storeintracellular calcium ion . When the muscle is stimulated , calciumions are released from its store inside the sarcoplamic reticulum ,into the sarcoplasm .

3. With adequate fuel and oxygen(aerobic) , muscle cell can contract repeatedly without fatigue .During anaerobic condition (higher intensity exercise) , musclecells must rely on other reactions that donot require oxygen tofuel muscle contraction . The anaerobic metabolism in cells producewaste molecule that can impair muscle contractions (fatigue) .

4. In reflex action , when receptorsof sensory organ sense the danger , they send signal throughsensory neuron to spinal cord which passes the signal to otherinterconnected neurons . It is then received by relay neuron whichis present in spunal cord . Immediately, spinal cord sends backsignals to the muscle through motor neuron . And the muscleaatached to sense organ move the organ away from danger .