Nerve Conduction: Definition, History and Characteristics
Nerve conduction is defined as the process of transmission of electrical signals along a nerve. It is an important part of the body’s nervous system, allowing for communication between the brain and the various organs and limbs. This process occurs when an electrical impulse, generated by the firing of an action potential, travels along the axon of a neuron. The impulse is then transmitted to the next neuron, and so on. This transmission of signals is responsible for many of the body’s functions, including muscle contraction and coordination.
History
The first scientific study of the process of nerve conduction is attributed to a German physician and anatomist, Hermann von Helmholtz, who published a paper in 1853. In his paper, he described the electrical properties of nerve cells and the way in which they conduct signals. Helmholtz’s work laid the foundation for future research and discoveries in the field.
In the early 20th century, scientists such as Otto Loewi and John Eccles made significant contributions to the study of nerve conduction. Loewi discovered the role of neurotransmitters in the transmission of signals within the nervous system, while Eccles studied the electrical properties of nerve cells. Both scientists made major advances in the understanding of nerve conduction, which enabled a better understanding of how the body communicates with itself.
Characteristics
Nerve conduction is a complex process, but some of its basic characteristics can be understood. The electrical signal generated by the action potential is composed of three components: an initiation phase, a propagation phase, and a refractory period.
The initiation phase is the first step in the process, where the action potential is generated and the electrical signal is transmitted. The propagation phase is the second stage, where the signal travels along the axon of the neuron. Finally, the refractory period is the time which the neuron needs to reset itself before it can generate another action potential.
In addition to these basic components, there are other characteristics of nerve conduction which are important to understand. For example, the speed of conduction can be affected by the size and length of the axon, as well as the degree of myelination. Myelination is a process which increases the speed of conduction by wrapping the axon with a fatty substance known as myelin.
References
Bennett, M.R., & Plum, F. (2018). Chapter 2: Nerve Conduction. In Kandel, E.R., Schwartz, J.H., & Jessell, T.M. (Eds.), Principles of neural science (5th ed., pp. 63–86). McGraw-Hill Education.
Helmholtz, H. von. (1853). On the sensations of tone as a physiological basis for the theory of music. In C.P. Stein (Trans.), Annals of the New York Academy of Sciences, 3, 371–418.
Loewi, O. (1921). Über humorale Übertragung der Herznervenwirkung. Pflüger’s Archiv für die gesamte Physiologie des Menschen und der Tiere, 154, 633–639.
Eccles, J.C. (1957). The Physiology of Nerve Cells. Baltimore, MD: Johns Hopkins University Press.