Not surprisingly, this part of the nervous system is able to operate with great speed. On the other hand another part of the nervous system controls the muscular contractions of the digestive tract. This part of the nervous system does not need to effect such a rapid response in the target tissue. Therefore one might predict that the part of the nervous system that must operate at great speed will have some special structural features. The following two lectures will attempt to provide some answers to these questions.
Spinal nerves carry impulses to and from the spinal cord.
Cranial nerves carry impulses to and from the brain. The motor division is further subdivided into the somatic nervous system and the autonomic nervous system. The autonomic nervous system is divided into sympathetic and parasympathetic systems. The basic unit of the nervous system is the neuron. While they can have different forms they generally consist of the soma or cell body, the dendrites and the axon.