Neurons

The neuron serves as the basic anatomical and physiological unit of the nervous system. It consists of the perikaryon or cell body and contains such structures as the nucleus, Nissl bodies, neurofibrils, lysosomes, mitochondria, and Golgi apparatus. A mature neuron does not contain a mitotic apparatus. The Nissl bodies are masses of rough endoplasmic reticula and are involved in protein synthesis. The neurofibrils are hollow microtubules that are involved in nerve impulse conduction, support for the cell, and transportation of nutrients.

The perikaryon has two types of cytoplasmic extensions: dendrites and axons. The dendrite transmits a nerve impulse toward the perikaryon. It may have its distal end modified as a receptor and may be highly branched. The axon transmits an impulse away from the perikaryon. The axon may have side branches that are called axon collaterals.

The neuron may have associated with it specialized cells called Schwann cells. Within the peripheral nervous system, the Schwann cell is responsible for the formation of the myelin sheath and neurolemma. Within the central nervous system, the myelin sheath is formed by oligodendrocytes. The presence of a myelin sheath imparts a whitish color, hence the term white matter, insulates the neuron, and increases the speed of nerve impulse conduction. The neurolemma is necessary for the regeneration of a nerve fiber. Since the Schwann cell is an actual living cell, it has a nucleus. Breaks or gaps at regular intervals in the myelin sheath are called nodes of Ranvier.

The space or gap between two neurons is called the synapse. The space or gap between a neuron and a muscle fiber is called the neuromuscular junction (Figure 134).

Peripheral Neuropathy Natural Treatment Options

Peripheral Neuropathy Natural Treatment Options

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