All animals have a finite life span and humans have remained about the same through out history. Some see aging as a path to frailty and increased vulnerability to injury and disease. Some see aging as a path to wisdom, experience, patience and acceptance.
Aging is defined as the physical and mental changes in a person over time. Some see aging as a path to frailty and increased vulnerability to injury and disease. Some see aging as a path to wisdom, experience, patience and acceptance.
All animals have a finite life span and humans have remained about the same through out history. The average age of a healthy human is around 85 but some do reach 100.
Theories that are about aging are:
1. The worn template concept is that every time a cell division errors take place.
2. The accumulated toxins theory where it is believed that the body is gradually poisoned by
accumulation of chemicals.
3. The immune surveillance theory that there is a progressive decline in the immune system
ability to fight off disease , tumors, etc.
Aging is related to the degenerative changes in organs and tissues of the body. The skin, bones, joints, blood vessels and nervous tissue. Brain cells specialized kidney units and many other body structures are never replaced after they reach maturity.
Things that accelerate age are:
Excessive alcohol use
Excessive exposure to sunlight
There have been extraordinary reports of 90 year old who have smoked and drank alcohol all their lives. Life expectancy may be genetic and may depend on heredity.
The aging skin losses elastic tissue allowing skin to sag or wrinkle. Blood capillaries weaken and skin bruises easy. This process can be speeded up by exposure to the sun and smoking.
The brain and nervous system are effected when loss of nerve cells begin to reduce the ability to memorize or learn skills. Responses become slower because reaction time of nerves increase. Excessive use of alcohol, drugs or excessive head trauma cause extensive damage to the brain and the nerves.
The senses because of loss of nerve cells lose acuity in all senses. With hearing the over exposure to loud noise would effect how a person hears. Smoking also affects many of our senses.
The lungs become less efficient because of loss of elasticity. Many things in life cause this such as air pollution, smoking, and lack of exercise.
The effects of aging on the cardiovascular system is influenced by the heart. As fibrous tissue replace muscle fibers in the muscular organ (the heart) changes take place. The diminished contractibility and filling capacity begin to change as years go by. The heart becomes less tolerate to exercise. Heart valves thicken and abnormal closing of the valves may occur. Murmurs may also occur. The cardiac output decreases with age. External things such as use of alcohol , cigarettes, and fatty diets are factors that determine the speed in which these things happen.
The circulation is affected as arteries harden causing poor blood circulation and high blood pressure. The things that speed up this process are lack of exercise , smoking, and poor diet.
The joints where wear on hips and knee joints reduce mobility. Pressure on intervertebral disks causes height loss. These problems usually result from earlier athletic injuries and being over weight.
The muscles lose bulk and strength because of lack of exercise and starvation.
The liver becomes less efficient and toxic substances are not removed from the blood. This also happens as a result of alcohol consumption and virus infections.
Some factors that diminished output become apparent are:
Illness in elderly
Strenuous physical activity
As a human ages their physical performance declines. Some of these at around age 60 are:
Exercise history determines how physical strength declines
Lung function declines
Wound healing and resistance to infection declines
Sexual activity is variable depending on how sexually active a human is
Mental abilities deteriorate benign forgetfulness takes place
The decline in infant and childhood mortality has decreased over the years. Few adults under 50 these days die from natural causes. This has increased the proportion of people who live past the age of 65. Over a third of the people who live past 70 have a disability.