Nerve fibres of the parasympathetic nervous system arise from the central nervous system. Specific nerves include several cranial nerves, specifically the oculomotor nerve, facial nerve, glossopharyngeal nerve, and vagus nerve. Three spinal nerves in the sacrum (S2-4) also act as parasympathetic nerves.
The word longevity is sometimes used as a synonym for life expectancy in demography - however, the term longevity is sometimes meant to refer only to especially long-lived members of a population, whereas life expectancy is always defined statistically as the average number of years remaining at a given age.
At the root of longevity is the word long. So when you see longevity, think âa long time. In fact, this word has some serious longevity, since it's been around since the 1600s. Longevity is most commonly used to describe the length of oneâs lifetime, but it can also mean a long duration, such as oneâs longevity working for a certain company for an extended period of time.