muscular system

the function of the system

the function of this system is to move the skeletal, maintain posture through steady contraction and generate heat through cell metabolism.

the contraction of the muscle

the contraction of the muscle can be decided in to 4 stages


1 muscle activation ; the motor nerve stimulates an impulse to pass down a neuron to the neuromuscular junction, this stimulates sarcoplasmic reticulum to release the Ca ion to the muscle cell.

2 muscle contraction; Ca flows in to the muscle cell, makes actin and myosin to bind up. The actin and myosin cross bridge contract using energy as AT

3 recharging; ATP is re-synthesized allowing actin and myosin to hold their strong binding together.

4 the impulse of the nerve stop caused the Ca to flow back to the sarcoplasmic reticulum that unbounded the actin and myosin , from then the muscle relaxed

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the disorder of the muscular system

1 muscular dystrophy : this type of disorder in inherit and can spread by the mother. It causes the muscle to lack of the protein called dystrophin that hold the skeletal muscle cells together and the muscle tissues are replaced by the fatty deposits.

the symptoms are the weakening of the muscle, the fatigue of the muscle eventually loss of strength. there is no treatment that can fully cure this type of disorder but some medication can slow down the course of the disease. the prevalence of this disease is shown below by the graph

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the disorder of the muscular system

2 ALS ; a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. Motor neurons reach from the brain to the spinal cord and from the spinal cord to the muscles throughout the body.

the symptoms are the weakening of the muscles and fatigues. there is no treatment that can fully cured the disease but some of the medication can slow the symptoms down. the prevalence is shown below

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