Physiologic changes that occur with aging do not necessarily cause disability. Aging does not inevitably lead to declining levels of cardiac functioning, bone density, muscular strength, cognitive ability and memory, sexual desire and activity, physical and social functioning, nor does aging insure rising levels of blood pressure, cholesterol and anemia. However, there are some inevitable changes that do occur with aging. Listed here are some of the expected changes in various body systems that occur as we age. How much change there is in any specific body system depends upon numerous factors, including our basic heredity, our lifestyle maintained over the years, our emotional makeup, and how we have learned to cope with the disappointments, losses, problems, setbacks and normal ups and downs of life.
o Heart and Blood Circulation
The heart becomes less efficient and has to work harder as we age. There is a decrease in maximum pumping rate and decreased oxygen extracted from the blood. The heart muscle gradually thickens and increases in size while arteries tend to stiffen as fatty deposits and plaque accumulate in blood vessel walls. As a result, most of us experience a gradual decline in energy and endurance over the years and many develop atherosclerosis and othe heart problems.
o Metabolism, Body Composition and Body Fat
Gradually declining metabolism along with hormonal changes often leads to diminished muscle tone. Body fat tends to increase until middle age, stabilize for several years, and then gradually decrease in the elderly. However, as we age, layers of fat tend to redistribute from beneath the skin to surround the deeper organs. Women often store fat in the hips and thighs while men tend to develop larger abdomens. Medicine and alcohol are processed more slowly and reflexes become slower while driving or participating in sports and other activities.
o Brain and Nervous System
Starting in our thirties, there is a gradual loss and damage of some neurons, blood flow diminishes, brain weight decreases, and there is gradual loss of brain cell functioning, including memory changes, inability to recall recent events or remember names and details. However, the brain adapts to these changes by increasing the number of connections between cells (synapses) and dendrites and axons (branch-like extensions) that carry messages in the brain. A study in the Journal of Neuropsychology, suggests that higher education can actually prevent age-related cognitive decline by enabling older people to call up reserves from the brain’s frontal lobes. Potential life-span of man is about 115-125 years. In mammals, there seems to be a strong correlation between length of life and brain weight.
Starting in our mid-thirties, our bones gradually become less dense and strong, losing minerals faster than they can be replaced. Bone loss tends to increase in many women after menopause, leading to increased risk of osteoporosis. By age 65, one in three people report falls; one out of 20 ends in a fracture.
o Lungs and Breathing
Beginning in our twenties, lung tissue loses elasticity, rib cage muscles shrink and our maximum breathing capacity diminishes. As we age, especially for inactive people, the lungs become increasingly less efficient and the body cells receives less oxygen.
o Kidneys and Bladder
Kidneys decline in size and function as we age, becoming less efficient at handling dehydration or extracting wastes and some medications from the blood. As bladder capacity declines, urination may be more frequent and if the tissues atrophy, urinary incontinence may result.
Without exercise, muscle mass declines as much as 22 percent for women and 23 percent for men between the ages of 30 and 70. Strong muscles, however, pluck oxygen and nutrients from blood more efficiently, create less work for the heart, and help the body to stay sensitive to insulin and sop up sugar from the blood.
As we age, our body decreases its production of collagen and our oil glands produce less oil, making our skin gradually less elastic, drier, and more wrinkled. We may develop age spots or liver spots (brown, yellow, white or red) caused by decreases in melatonin, buildup of waste products, and developing carcinomas.
o Hair, and Nails
Our hair and fingernails grow more slowly as we age and we also heal more slowly from wounds. The hair on our scalp, pubic area, and armpits gradually thins and the loss of hair pigment cells leads to gray and eventually white hair. Nail appearances can be warning signs for serious medical conditions, but nail changes are rarely the first clue. For example, red nail beds may indicate heart disease while pitting and rippling of the nail surface suggests inflammation such as arthritis. White nails may indicate liver disease or anemia, while yellowish, thick and slow-growing nails could suggest lung disease.