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As we grow older we experience physical changes. Some of those changes are "normal" and other are considered "pathological". To be considered normal four conditions must be met. Changes must be (1) universal--that is it occurs in all members of the species to a certain degree; (2) progressive---changes occur gradually over time; (3) irreversible--one can slow down the processes of aging, but it continues no matter what the intervention, and (4) deleterious--which means it gets progressively worse.
Growing old is inevitable but the rate of aging is very individual. It is important for caregivers to understand what conditions to expect as one ages as opposed to pathological conditions which require treatment and management.
Several books have discussed age changes that occur normally as we age. The information below is adapted from Carol Miller, Nursing Care of Older Adults. Glenview Illinois: Scott, Foresman/Little, Brown Higher Education, 1990. and Ellen Cervantes, et. al. The Paraprofessionals in Home Health and Long-Term Care. Training Module for Working with Older Adults. Health Professions Press, Inc: Baltimore Md.: 1995.
All of the body's systems experience changes in aging. These systems include:
- Integumentary System
- Muscoskeletal System
- Cardiovascular System
- Respiratory System
- Digestive System
- Urinary System
- Lymphatic/Immune System
- Nervous System
- Sensory System
- Endocrine System
- Reproductive System
The integumentary system includes the skin and its accessory organs which comprise the largest and most visible body systems. The skin protects individuals from infections, harmful environmental influences and minimizes water loss. The large surface of the skin regulates body temperatures and the elimination of salts and waste products through sweating. Sensory receptors in the skin allow response to environmental changes that occur. There are two layers to the skin; the epidermis and dermis. The epidermis is covered by a layer of dead cells and the dermis consists of nerve endings, capillaries, hair follicles; sweat and sebaceous oil glands, and connective tissues. All these structures experience age-related changes.
The most common age changes that occur within the Integumentary System include a loss of elastin fiber, thinning of the dermis and epidermis; fewer sebaceous glands to lubricate the skin, a diminished amount of sweat glands; a decrease in subcutaneous fat and an increase in "age spots" due to changes in the pigment "melanin." Additionally, the capillaries in the skin become more fragile and susceptible to ruptures.
The impact of these changes include: (1) possible negative self esteem due to an increase in wrinkles and changes in appearance; (2) an inability to regulate body temperature which is one reason why elderly individuals tend to be chilly or cold; even on hot days; (3) dry skin requiring the use of emollients or moisturizers (4) greater susceptibility to sunburns, and (5) an increase in bruising.
The Muscoskeletal System includes the bones, muscles, and joints. The skeleton consists of over 200 bones cartilage and ligaments that bind the bones together. Bones are responsible for forming red and white blood cells in the bone marrow, and muscles support the skeleton. Age-associated change that occur are a decrease in muscle strength and mass, and as a result, an increase in body fat. Joints become stiffer with age due to calcification, fraying or cracking of cartilage and ligaments. Additionally, the bone strength and mass are also reduced with advancing age. Perhaps the most obvious changes that occur is the padding between the bones that becomes compressed, resulting in a gradual decrease in height.
The good news is that physical activity can help to compensate for these changes. Physical activity is important well into the advanced years. Physical strengthening can reduce the rate progressive deterioration that occurs. As individuals age they become more susceptible to falls and compression fractures due changes in mineral absorption. The caregiver therefore, needs to take extra care when helping a person transfer from a standing to sitting position or from a sitting to lying position to avoid dropping the body weight and thereby creating compression fractures.
The cardiovascular system includes the heart, blood, and vessels; including arteries, capillaries and veins. The heart pumps the blood through the body which carries nutrients from the digestive system; hormones, antibodies and waste products.
The age-associated changes that occur in the cardiovascular system have little impact on the activities of daily living. These changes include: an increase in heart size or hypertrophy of the heart; hardening of the arteries, less elasticity of the veins resulting in an increase in blood pressure as we age, and a less responsive baroflex mechanism, the mechanism responsible for regulating blood pressure changes.
The respiratory system is very complex and undergoes several age-related changes. The respiratory system consists of the nose, mouth, pharynx, larynx trachea, lung, bronchi, alveoli, and diaphragm. The major function of the system is to transfer oxygen from the air into the bloodstream and to remove carbon dioxide from the bloodstream and the environment.
Age-associated changes includes the reduced amount of oxygen intake; a decreased gag reflex, decreased efficiency in oxygen and carbon monoxide exchange, and an increase in the amount of residual lung capacity as one ages. This all leads to decreased lung functioning and can cause the older person to feel easily fatigued after minor physical exertion. Aerobic exercise will help to compensate for these changes.
The digestive system includes the mouth, pharynx, salivary glands, esophagus, pancreas, gallbladder, small and large intestine, liver, appendix, rectum and anus. It involves the breakdown and absorption into usable nutrients and elimination of wastes. The changes in the digestive functioning have very little impact on the activities of daily living. The changes that occur include: a delay in emptying time of the stomach; which results in a feeling of being full with small portions of food; a decrease in the production of salvia which makes elderly individuals more susceptible to infections; a decrease in mucous within the intestines and a decrease in gastric juices. There is some evidence to indicate that these normal age changes have a slight effect upon absorption of important nutrients such as calcium and the absorption of vitamins. The decrease in gastric juices may cause individuals to complain of heart burn or cause them to be sensitive to spicy food. Additionally, the decrease in mucous can also make it difficult to eliminate bowel movements. It is often stated that "constipation" is a normal part of aging. Studies indicate however, that constipation commonly occurs in older adults because of diminished activity and mobility, lack of dietary fiber and fluid, adverse medication effects and the use of long-term laxatives. (Miller, 2000)
The urinary system consists of a kidney, bladder, and urethra which carries the urine outside the body. The kidneys are composed of tubules called nephrons which are the filtering system of the body. The bladder stores urine and eliminates waste when it is half-full and receives sensors from the brain.
The age changes that occur do effect senior's self-esteem and their desire to go outside their homes. First, the kidney decreases in size and efficiency. This effects the elimination and filtration of medications. Additionally, the bladder can hold less fluid due to changes in size and elasticity, and more urine remains in the bladder when voiding. As a result, older people may need to urinate more often, and the residual urine may predispose older adults towards bladder infections. Also, due to neurological changes the time between the urge to void and the need to void has decreased--which means when older individuals feel the need to urinate they must do so quickly. These changes, in addition to a change in thirst sensation, often cause older adults to reduce their liquid intake. This of course, results in dehydration and can create problems with constipation as well.
The lymphatic system has two major functions: (1) to collect excess fluid from around the cells and return it to the bloodstream, and (2) to protect the body through immune cells from bacterial and viruses. When someone has an infection the lymph nodes located throughout the body enlarge. The lymph system includes the thymus, spleen and lymph nodes located in the neck, underarms, inside the chest and abdomen, in the groin and around the joints such as the elbow.
The age-associated changes that occur as one ages is highly variable. There is some research to show that the number of T-helper cells used to fight infection decreases with age. Generally, there is some evidence to suggest that older people's antibody production does not respond as vigorously as younger adults.
The central nervous system consists of two central components; the central and peripheral. The central nervous organs are the brain and spinal cord responsible for sending nerve impulses to the peripheral system; or the organs, glands and muscles. Both components consist of nerve cells or neurons which store and conduct information.
Years ago, it was believed that neurons stopped producing early in life. However, new research conducted by University of California Irvine Neurobiology Center, indicates that the brain is much more plastic than it was once thought, which means that individuals should continue to learn new things as they age. The age changes that do occur include: a decrease in brain weight, a decrease in blood supply to the brain, accumulation of lipofuscion,an age-associated pigment in the neurons and gilial cells; and a graduate but moderate decline in short-term memory loss. Generally, an older person's perception of memory loss is often far worse than reality. Additionally, there is a reduction in the speed of processing information, and a reduction in reaction time.
The nervous system depends on specialized sensory receptors to gather information about the internal and external environment. The receptors include those needed for vision, hearing, smell, touch, equilibrium, and pain sensation. Sensory decrements have a psychosocial impact upon the individual; however individuals adapt because these changes are gradual and most are able to adapt to the changes.
Vision changes that occur as one ages are significant. With age, the lens of the eye thickens, yellows, clouds and becomes less elastic. The thickening of the lens reduces the amount of light. As the lens becomes less elastic, it loses its ability to focus on close objects. This occurs in middle age and is called "presbyopia." The changes in elasticity also create a narrowing of the visual field, and diminished depth perception. The yellowing of the eye and changes in size and thickening of the cornea make it difficult to see at night. With age the fluids in the eye become cloudy reducing light sensitivity. The cornea becomes thickened and less transparent with age. The thickened cornea scatters light inside the retina making glare more of a problem. Lastly, the changes in the eye also effect color perception making it difficult to distinguish between blues, greens and violets.
The ear consists of the outer ear, middle ear, and inner ear. Presbycusis is the hearing loss associated with the aging process. With presbycusis elders complain of the inability to hear high frequencies and are unable to hear consonant sounds such as f, g, s, z, t, sh, and ch. Other age changes involve the collapse and narrowing of the auditory canal and thickening of the earwax. This increases the difficulty in hearing.
Generally, with age there is a decrease in the number of taste and smell receptors and slower nerve transmissions, although the losses are highly variable. The loss of taste and smell receptors means that food is not appetizing to the older adult. Older adults are less likely to detect the bad taste of spoiled food and a reduced ability to smell may make them unable to smell smoke, gas leaks or other toxic fumes.
Many elderly individuals experience changes in balance due to changes in the vestibular system; located in the ear. Changes in these system can cause postural hypotension due to the inability to quickly respond to changes in position. This often causes dizziness or lightheadedness when one moves quickly from a lying or sitting position to standing.
The somatic receptors respond to touch, pressure, cold, pain, or body position. It is generally believed that these receptors become less sensitive with age. Elderly individuals therefore experience decrease ability to feel pain, The decrease in receptors make it more difficult for the elderly person to cope with changes in temperature.
The endocrine system transits chemical messages or hormones throughout the body. They manufacture and release chemical messengers. Information regarding changes within the endocrine system are difficult to pinpoint, however, researchers have documented changes in estrogens, androgens, insulin, thyroid and growth hormones. The decrease in production of these hormones results in decreased metabolic rates and the inability of the body to respond as rapidly to stress, and cells that become more resistant to absorbing insulin.
The proper functioning of the reproductive system depends upon the relationship between the pituitary, hypothalamus, testes and ovaries. The change most familiar to individuals is menopause where women lose the capacity to bear children. After menopause, women experience a shrinking of ovaries, loss of subcutaneous fat around the external genitalia, thinning of pubic hair, dryness and loss of elasticity of the vaginal canal. The reduced vaginal acidity increases the risk for yeast, and the dryness and loss of elasticity can cause painful intercourse. The decrease in the production of estrogens is associated with an increased rate of bone loss, changes in cholesterol levels and an increased risks of cardiovascular disease.
Changes that occur in men within the reproductive system is highly variable. Generally there is a decrease in ejaculatory force, it takes more time to achieve and erection, there is a decline in the number of viable sperm, and there is an enlargement in the prostrate. The most notable impact of these changes are an increased frequency and urge to urinate, as well as a decreased force of steam and urinary retention.
pp. 65-102. Anita G. Beckerman, and Ruth M. Tappen (2000). It Takes More than Love: A Practical Guide to Taking Care of An Aging Adult. Baltimore Md: Health Professionals Press.
