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.
DEFINITION of 'Perpetual Bond'. A bond with no maturity date. Perpetual bonds are not redeemable but pay a steady stream of interest forever. Some of the only notable perpetual bonds in existence are those that were issued by the British Treasury to pay off smaller issues used to finance the Napoleonic Wars (1814).