Anatomy and Physiology
The Basics of Aging
Are you feeling older these days? There is some good news and some bad news about aging.
First, the good news:
Life spans in the United States had been increasing steadily since 1900. An American male born at the turn of the last century could expect to live only about 46 years. Life expectancies for both American men and women are now in the 70s.
Life expectancies are increasing not just for new generations, but also for “old folks.” A 70-year-old man alive in 2007 can reasonably expect to see his early eighties; and today’s 70-year-old woman can expect to live until age 85.
Now, the bad news:
Life expectancies are not limitless. Most scientists and doctors believe that 125----give or take a few years---is the upper limit for humans.
What affects longevity?
Longevity can be affected by a number of factors, including heredity and lifestyle. Your life span can also be influenced by the presence of toxic substances in the environment, and the development of new medical care techniques.
How does aging affect the body?
Just about every part of your body feels the years as you get older. After the age of 35, the following changes begin to occur:
Hearing becomes less acute. The ears lose ranges in the higher and lower pitches. A few decades past your 35th birthday, it may become more difficult for you to distinguish certain consonants (s, p, k, and ch). (This is why elderly people frequently complain that others are mumbling.)
Body fat increases---but in all the wrong places. Fat deposits around the waist and buttocks expand. Meanwhile, there is less fat directly under the skin. (This is one factor that leads to wrinkling.)
Foods don’t taste as good as they once did. As you age, you lose taste buds and the ability to detect subtle odors. (Both taste buds and the sense of smell affect the taste of food.)
The eyes also change. The lenses become stiffer. The retina looses some of its sensitivity to light; the pupils become slower to react to changes in light levels.
Internal organs also begin their decline during the 30s. (But don’t worry too much: your organs have much more capacity than you need; and the changes are incremental.) These include:
Lungs: Decrease in capacity and their ability to transfer oxygen
Heart: The heart muscles stiffen; and the organ’s maximum pumping output falls.
Kidneys: Begin to shrink. This means a smaller blood flow passing through these organs. As a result, the urine is diluted. Medicines and toxins may linger longer in the body.
What else? Here are a few more effects of aging:
Excretion becomes more difficult as bladder walls weaken.
The immune system slows down, allowing more diseases and infections to invade the body.
Oh well, none of us is going to live forever…
