Bioelectromagnetism

From Wikipedia, the free encyclopedia

Bioelectromagnetism (sometimes equated with bioelectricity) refers to the electrical, magnetic or electromagnetic fields produced by living cells, tissues or organisms. Examples include the cell potential of cell membranes and the electric currents that flow in nerves and muscles, as a result of action potentials.

[edit] Description

Biological cells use bioelectricity to store metabolic energy, to do work or trigger internal changes, and to signal one another. Bioelectromagnetism is the electric current produced by action potentials along with the magnetic fields they generate through the phenomenon of electromagnetism.

Bioelectromagnetism is studied primarily through the techniques of electrophysiology. In the late eighteenth century, the Italian physician and physicist Luigi Galvani first recorded the phenomenon while dissecting a frog at a table where he had been conducting experiments with static electricity. Galvani coined the term animal electricity to describe the phenomenon, while contemporaries labeled it galvanism. Galvani and contemporaries regarded muscle activation as resulting from an electrical fluid or substance in the nerves.

Bioelectromagnetism is an aspect of all living things, including all plants and animals. Bioenergetics is the study of energy relationships of living organisms. Biodynamics deals with the energy utilization and the activities of organisms. Some animals have acute bioelectric sensors, and others, such as migratory birds, are believed to navigate in part by orienting with respect to the Earth's magnetic field. Also, sharks are more sensitive to local interaction in electromagnetic fields than most humans. Other animals, such as the electric eel, are able to generate large electric fields outside their bodies.

In the life sciences, biomedical engineering uses concepts of circuit theory, molecular biology, pharmacology, and bioelectricity. Bioelectromagnetism is associated with biorhythms and chronobiology. Biofeedback is used in physiology and psychology to monitor rhythmic cycles of physical, mental, and emotional characteristics and as a technique for teaching the control of bioelectric functions.

Bioelectromagnetism involves the interaction of ions. Bioelectromagnetism is sometimes difficult to understand because of the differing types of bioelectricity, such as brainwaves, myoelectricity (e.g., heart-muscle phenomena), and other related subdivisions of the same general bioelectromagnetic phenomena. One such phenomenon is a brainwave, which neurophysiology studies, where bioelectromagnetic fluctuations of voltage between parts of the cerebral cortex are detectable with an electroencephalograph. This is primarily studied in the brain by way of the electroencephalogram or "EEG."