Ch 17. Physical Development in Late Adulthood Flashcards
Life Span
The maximum number of years an individual can live. The life span of human beings is about 120 to 125 years of age.
Life Expectancy
The number of years that will probably be lived by the average person born in a particular year.
Evolutionary Theory of Aging
This theory states that natural selection has not eliminated many harmful conditions and nonadaptive characteristics in older adults; thus, the benefits conferred by evolution decline with age because natural selection is linked to reproductive fitness.
Cellular Clock Theory
Leonard Hayflick’s theory that the maximum number of times that human cells can divide is about 75 to 80. As we age, our cells have less capacity to divide.
Free-Radical Theory
A microbiological theory of aging that states that people age because normal metabolic processes within their cells produce unstable oxygen molecules known as free radicals. These molecules ricochet around inside cells, damaging DNA and other cellular structures.
Mitochondrial Theory
The theory that aging is caused by the decay of mitochondria, tiny cellular bodies that supply energy for function, growth, and repair.
Hormonal Stress Theory
The theory that aging in the body’s hormonal system can decrease resistance to stress and increase the likelihood of disease.
Neurogenesis
The generation of new neurons.
Cataracs
A thickening of the lens of the eye that causes vision to become cloudy, opaque, and distorted.
Glaucoma
Damage to the optic nerve because of the pressure created by a buildup of fluid in the eye.
Macular Degeneration
A disease that involves deterioration of the macula of the retina, which corresponds to the focal center of the visual field.
Arthritis
Inflammation of the joints that is accompanied by pain, stiffness, and movement problems; this disease is especially common in older adults.
Osteoporosis
A chronic condition that involves an extensive loss of bone tissue and is the main reason many older adults walk with a marked stoop.
