The following terms are related to the study of aging.  You should be come comfortable with meaning of each of these terms as they will be used throughout the text and class discussions.

• Aging is the process of growing old, regardless of chronological age.
• Senescence is a term used to describe the group of deleterious effects that lead to a decrease in the efficient functioning of an organism with increasing age and to an increased probability of death.
• Senility refers to the physical and mental deterioration often associated with old age.
• Elderly describes a person who is 60 to 75 years of age, as defined by the World Health Organization.
• Old describes a person who is 76 to 90 years of age, as defined by the World Health Organization.
• Very old describes a person who is over 90 years of age, as defined by the World Health Organization.
• Gerontology is the scientific study of the process of aging.
• Geriatrics refers to health care delivery for the elderly.  It is the branch of medicine that treats the conditions and diseases associated with aging and old age.
• Longevity refers to the duration of life of an individual.
  • Mean longevity is the average longevity of a population.  This often referred to as life expectancy.
  • Maximum longevity is the age at death of the longest-lived member of the population.
• Demography is the statistical study of human populations collectively, including geographic changes and trends in births, marriages, diseases, and deaths.