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.
phosÂ·phoÂ·diÂ·esÂ·ter bond. n. The covalent chemical bond that holds together the polynucleotide chains of RNA and DNA by joining a carbon in the pentose sugar of one nucleotide to a carbon in the pentose sugar of the adjacent nucleotide.hosÂ·phoÂ·diÂ·esÂ·ter bond. n. The covalent chemical bond that holds together the polynucleotide chains of RNA and DNA by joining a carbon in the pentose sugar of one nucleotide to a carbon in the pentose sugar of the adjacent nucleotide.