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1) a. Decorticate posturing means rubrospinal tract is the dominant output to the motor neurons of the body... maybe dominant is the wrong word, I am not all that knowledgable on this subject, but it is certainly altering the standard reticulospinal tract based extensor posturing. http://en.wikipedia.org/wiki/Rubrospinal_tract It is responsible for the ...


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From Uptodate on Clinical Manifestations of Hypocalcemia: Acute hypocalcemia directly increases peripheral neuromuscular irritability [ 1 ]. As measured electromyographically, tetany consists of repetitive high-frequency discharges after a single stimulus. Hyperexcitability of peripheral neurons is probably the most important pathophysiologic effect of ...


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It is a question of transmembrane potential. Ca++ being a cation, means that if you decrease the amount of ionized calcium in the extra cellular fluid, it conceptually is nearly equivalent to having a more positively charged intracellular fluid. This in turn means that the cell will be closer to its threshold potential for depolarization, therefore ...


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If we consider another case, there is blood flow, but no new oxygen is coming into the system, the brain cells may begin to die after about four minutes [1]. However, this depends on the person not the amount of time. Consider free divers and more specifically Tom Sietas. These men and women, in this sport, can go well beyond the 5 minute mark with no ...


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From Boron and Boulpaep textbook of Medical Physiology, second edition, p.289: Because of falling ATP levels in the brain, consciousness is lost within 10 seconds of a blockade in cerebral blood flow. Irreversible nerve cell injury can occur after only 5 minutes of interrupted blood flow. If conscious is lost within 10 seconds of blockade in cerebral ...


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The nature of time has been discussed for millenia. We don't know exactly why or where time perception exists, but we do have some information on how it is perceived. The circadian rhythm is basically in place to help us sleep, wake and perform tasks in a 24 hour cycle of light. Robbed of light, and the melatonin it's absence produces, the rhythm shifts ...


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Humans and many other organisms have a circadian clock, a biological system that oscillates every 24 hours (but is also sensitive to external stimuli). There are many components to the human circadian clock that are not known. On the molecular level, gene regulation, post-transcriptional and post-translational modification are all implicated. There is also ...



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