Stages of Human Development-Biological Aging
"The gradual changes in the structure and function of humans and animals that occur with the passage of time, that do not result from disease or other gross accidents, and that eventually lead to the increased probability of death as the person or animal grows older (Biology-Online, 2006)." The following paper will describe the aging process in humans from a biological systems perspective. In addition, changes that occur within the various systems of the body will be discussed in detail.
Integument comes from the word integumentum, meaning, "cover," or "enclosure." The human integumentary system is essential to life. Composed primarily of the skin, it protects, nourishes, insulates, and cushions. Accessory structures within this system include hair, nails, and certain exocrine glands. Accounting for approximately 7 percent of the body, the skin is the largest and heaviest organ of the body (Cohen & Taylor, 2005).
Without it, bacteria would attack an individual immediately, or death from heat and dehydration would occur.
Chronological aging affects biochemical changes to skin. The supportive fibers of collagen and elastin break down. Skin does not retain as much moisture as it once did. The skin's ability to fight infection, feel sensations, and regulate body temperature also diminishes. Fine lines around the eyes, deepened expression lines at the corners of the mouth and across the forehead, and sagging skin are some visible signs of aging skin. In addition, hair may become coarser, gradually lose color, or begin to thin, and nails become more brittle with age.
Photoaging of the skin is far more damaging than age alone. Over the years, sun exposure causes fine and coarse wrinkles; baggy skin with a yellow, leathery appearance; and dry, scaly skin. Because sun exposure diminishes collagen, which supports a network of blood...