Nervous System Essay, Research Paper

The Nervous system

The nervous system can be separated into three divisions, the cardinal nervous system, the peripheral nervous system, and the autonomic nervous system. The Central Nervous system consists of the encephalon and the spinal cord. The spinal cord is a long, thick nervus bole that Rus from the base of the encephalon down through the spinal column, or anchor. The cord is composed of white affair. A transverse sectional position of the spinal cord shows the grey affair as an H shaped country surrounded by white affair. Thirty one brace of spinal nervousnesss leave the spinal cord. Each of these nerve short pantss is attacked to the cord in two topographic points. The root of the nervus that leaves the cord toward the from to contend organic structure is called the ventral root or anterior root. The root that leaves toward the rear of the organic structure is called dorsal root or posterior root. Centripetal nervousnesss enter the spinal cord at the dorsal root. Motor nervousnesss leave the spinal cord at the ventral root. If the ventral root of a nervus is cut, the portion of the vody to which the nervus goes can non travel, but it still has esthesis. If the dorsal root of a nervus is cut, esthesis disappears, but the organic structure portion can still travel. Some nervus urges come ining the spinal cord are direc

ted to the encephalon.

The Peripheral Nervous system consists of 12 braces of cranial nervousnesss and the 31 brace of spinal nervousnesss. The Cranial Nervousnesss come from the lower portion of the encephalon. These neves control many esthesiss and actions including sight, odor, mastication, and get downing. The spinal nervousnesss leave the spinal cord at the little of the dorsum. Each of the 5 brace of sacral nervousnesss and the 1 brace of coccygeal nervousnesss leave the spinal cord between the lowest vertebrae in the spinal cord.

The autonomic Nervous system regulates the inernal variety meats of the organic structure. The fuctions it controls are nonvoluntary. For illustration, you can non intentionally command the rate of your pulse, though it may be influenced by your ideas or emotions.

The nervousnesss of the autonomic nervous system are connected to and regulated by the cardinal nervous system are connected to and regulated by the cardinal nervous sytem at a subconscious degree. The nervus fibres have lettle or no myelin sheath. Most nervousnesss in the autonomic system are effector velocity of more than 300 per second. In the smaller fibres of the autonomic nervous system, the lowerst portion of the encephalon. The membrane theory is the most normally accepted theory of how

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