Electricity physiological effects

With TMS, a brief but powerful electric current is passed through a small coil held against the scalp of a conscious patient. This generates a powerful local magnetic field which passes unimpeded through the skull and induces a weaker, less focused electric current within the brain. Due to the non-invasive nature of this method, the important physiological effects of TMS are likely to be a consequence of the density of the electric current and the electric field which is induced in the cortex. It is believed that the induced electrical fields cause neuronal depolarization which changes the neurotransmitter release mechanisms. 

ADRENAL MEDULLA HORMONES. Adrenaline (epinephrine) and its immediate biological precursor noradrenaline (norepinephrine, levartei-nol) are the principal hormones of the adult adrenal medulla. See Fig.l. Some of the physiological effects produced by adrenaline arc contraction of the dilator muscle of the pupil of the eye (mydriasis), relaxation of the smooth muscle of the bronchi constriction of most small blood vessels dilation of some blood vessels, notably those in skeletal muscle increase in heart rate and force of ventricular conlraction relaxation of the smooth muscle of the intestinal tract and either contraction or relaxation, or both, of uterine smooth muscle. Electrical stimulation of appropriate sympathetic (adrenergic) nerves can produce all the aforementioned effects with exception of vasodilation in skeletal muscle. 

OFQ/N and the ORLl receptor are also involved in a number of other physiological effects (see Refs. 87,891. One of the most significant effects is the anxiolytic activity of OFQ/N (1013), which has been postulated to be one of OFQ/N s most fundamental actions, and may help explain the effects of OFQ/N on other phenomena [e.g., locomotion, reward, and feeding (87)]. A small molecule ORLl agonist has also demonstrated anxiolytic activity (1014), demonstrating an important potential therapeutic application of these compounds. Like opioids, OFQ/N inhibits electrically induced contractions in the GPI and MVD smooth muscle preparations these effects are... 

Studies of electrochemical reactions of redox proteins have attracted widespread interest and attention. Such studies can yield important information about not only intrinsic thermodynamic and kinetic properties of redox proteins, but also structural properties, such as binding characteristics of proteins at specific types of electrode surfaces and the orientational requirements for electron transfer between the protein and the electrode. The results are useful for the development of biosensors, biofuel cells, and biocatalysts. In addition, the information obtained from these studies can contribute to an understanding of the physiological implications of biological electron transfer reactions, because many electron transfer proteins are located at, or close to, charged membranes and are thus subject to large electric field effects that are similar to those near an electrode surface. 

This deals with the identity of electricities derived from different sources , common (frictional), voltaic (current), magneto-electric, thermo-electric, and animal (the torpedo and gymnotus), and attempts to show that the physiological effect, magnetic deflection, power of magnetisation, spark, heating power, true chemical action, attraction and repulsion, and discharge by hot air, are exhibited by all of them. 

Physiological effects of electricity were known by the time Italian scientist Alessandro Volta first invented the battery in 1800. The introduction of the battery meant that a sustained source of electricity was available for the first time. Prior to that, electrostatic sources of electricity and storage devices, like the Leyden jar, were used. Such devices provided only momentary electrical current. 

One also cannot overlook the fact that these substances may have other physiological effects which contribute to the overall electrical behavior of the membrane. Continuing studies in this area may give a more defined explanation for the differences noted. 

The severity of the consequences of electric shock depends on a variety of factors. The physiological effects of electrical shock are not produced by electric potential (voltage) per se, but rather by the electric current that is driven by the potential difference that is applied externally to the body surface. Consequently,... 

TABLE 22.1 Electric Shock Current Levels and Physiological Effects (AC 60 Hz)... 

Smoke is produced by burning hydrocarbons and solids in considerable quantities, (particularly under conditions of incomplete combustion). It is also produced in large quantities by burning electrical and electronic equipment. Smoke consists of finely divided particulate matter and suspended liquid droplets (aerosols) and can contain toxic byproducts of combustion. Smoke creates a serious hazard to personnel due to its physiological effects and the reduction of visibility (most of the deaths on the Piper Alpha platform were of men in their living quarters who were overcome by smoke). 

The physiological effects that lead to the perceived improvement in the quality of the meat will not be considered here. What is of relevance is the potential for serious electrical injury to anybody who enters the stimulator enclosure while the rubbing electrode is live. Given that suspended animals as large as cattle have to be moved into and out of the enclosure, it can be... 

Hooker SP, Figoni SF, Rodgers MM, et al. Physiologic effects of electrical stimulation leg cycle exercise training in spinal cord injured persons. Arch Phys Med Rehabil 1992 73 470-476. 

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