ERECTION is orchestrated by the central nervous system. Erections are continuously inhibited by the sympathetic nervous system (blue). During REM sleep, however, when the sympathetic neurons in the locus coeruleus are turned off, erections occur spontaneously. The other brain structure that inhibits erections is the para-gigantocellular nucleus (PGN). Conversely, the parasympathet-ic nervous system (red) is excitatory. Tactile stimuli or stimuli processed in the cortex may be integrated in the paraven-tricular nucleus and the medial preoptic area (MPOA), triggering an erection. Some erections (called reflexive) occur entirely in the erection-generating center of the spinal cord, which runs from vertebra S3 to vertebra T12.
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Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.