Basically, there are two kinds of body movements, conscious movements and reflex. Conscious body movement is coordinated by the brain, e.g. when someone is bitten by insect, he/she will know there is a stimulus on his/her skin that comes from out of the body. This stimulus is received by nerve receptor on the skin. The stimulus then will be changed into nerve impulses. The impulses then will be transmitted to the brain by sensory nerve. By the brain, they will be translated so the brain will know that there is an insect biting on the skin. Then, the brain will instruct hand muscle (through motor nerve) to chase away the insect.
Human Body Movement
Unconscious body movement is called reflex. Reflex is coordinated by spinal cord but sometimes impulse can also reach brain. It depends on how strong the impulse is. Look at Picture, when kneecap is drummed with hammer, pain stimulus is received by receptor nerve. Stimulus then will be changed into impulse by receptor and go through pass the sensory nerve to the spinal cord. After processed by spinal cord, impulse will be sent to effector muscle (foot) by motor nerve and make a foot movement.
Read: Human Nervous System
Nervous system disorders can be fatal in all of organ system, e.g. amnesia and epilepsy. Amnesia is a memory disturbace that is caused by brain injury because of disease or hard head bump. Epilepsy is a electricity activity disturbance on nerve in the brain that can be temporary or permanently.