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.
Human bonding. Human bonding is the process of development of a close, interpersonal relationship. It most commonly takes place between family members or friends, but can also develop among groups, such as sporting teams and whenever people spend time together. Bonding is a mutual, interactive process, and is different from simple liking.