Based on what you have encountered throughout this module, share your answer to the following question:

Which normal physiological change do you feel has the most profound impact on older adult function? Select only one change to discuss in your initial post. Using medical terminology from the assigned reading is encouraged. Sharing of personal observations is encouraged.

Response Post:

Make at least one reply to another post, describing how the named physiological change would interact with your initially chosen physiological change to compound into increasing functional limitations.

Reading assigned below

Physiology and Aging

While the phrase “age is just a number” encourages people to stay active and challenge self-limiting beliefs, there are also normal age-related changes that make adults more susceptible to injuries and illnesses that impact quality of life with each decade. The aging population is growing; by 2050, the world population of people over 60 is projected to reach 2 billion (Sazlina 2015). This elevates the need for health providers and educators to engage the community in ways to age healthfully. Is it normal for older adults to have trouble going up stairs? Is it normal for older adults to forget things? Differentiating the “normal” from deviations that may benefit from medical consultation requires understanding physiology. Physiology describes how the body works. Studies of physiology are often broken down into body systems: cardiovascular, respiratory, gastrointestinal, genitourinary, musculoskeletal, nervous, endocrine, immune, integumentary, and special senses. Each system exhibits a normal functional decline with age, with most of the declines beginning in the late 20s or early 30s, then continuing throughout the lifespan (Katch, 2011). Fig 1. Normal age-related physiological declines. (Graphic created by Meredith Butulis, the course SME, based on info in Katch 2011).While we study systems in isolation for learning purposes, a change in one system impacts other systems, as all systems share one body. For example, many older adults have impaired insulin responses, making it harder for the body to absorb and use carbohydrates. This impacts not only our endocrine (insulin-glucagon) system but also our digestive efficiency and blood sugar, which can lead to weight gain. Weight gain can lead to obesity, which impacts activity levels, muscles, bones, and blood pressure (a cardiovascular condition). Blood sugar instability can also lead to changes in neurological function, such a mood instability and clouded thinking. Over time, this endocrine efficiency can often be managed with lifestyle modifications such as nutrition, sleep hygiene, exercise, and stress management. Without lifestyle adjustment to match changing physiology; however, many older adults are genetically predisposed to develop type II diabetes. Type II diabetes is a medical condition that can impair functional ability and increase morbidity and mortality by leading to additional conditions like heart disease. Considering the population impact on this globally rising health concern, as adults enter into Medicare or other government programs, the economic burden on society rises. As health educators in some capacity, what can you do to help people with preventative and management efforts? The answers to that question not only depend on your exact role and health care certifications and licenses, but also on being able to think critically; critical thinking to help people maximize quality of life draws from a rich base in understanding physiological changes, evidence-based preventative screening measures, and lifestyle modifications to detect and prevent disease progression.

Physiology Changes with the Normal Aging Process

Cardiovascular system: The heart and blood vessels work together to make up the cardiovascular system. With age, plaques build up in the blood vessels, narrowing their diameter and making them less elastic. This is called atherosclerosis, which predisposes aging adults to clots that can lead to heart attacks (myocardial infarctions), or strokes (cerebrovascular accidents). The heart is a muscle; it becomes less elastic and less efficient, losing strength with age; it has to work harder to keep circulation going, which decreases the capacity for high-intensity exercise. The equation 220-age = max predicted heart rate provides a rough estimate of the normal age-related decline.The cardiovascular changes in the heart and blood vessels together lead to difficulty with blood pressure regulation. Most often, this presents as high blood pressure (hypertension). However, many adults are on medications for chronic conditions that result in co-morbid low blood pressure when sitting up or changing positions (orthostatic hypotension). Orthostatic hypotension can present as dizziness and increases the risk of falls with getting out of bed or getting up from a chair. Respiratory system: The diaphragm muscle, lungs, and air passages (bronchi, trachea, larynx, pharynx, mouth, and nose) make up the respiratory system. With age, areas of cartilage ossify into bone, and spinal discs lose water content; this makes it harder for the thoracic spine and ribs to move. Coupled with decreased strength and elasticity of the diaphragm muscles, these musculoskeletal changes can lead to poor posture (kyphosis), decreasing breathing efficiency. This presents as shortness of breath (dyspnea), which often limits activity tolerance. Gastrointestinal system: This system includes the mouth, pharynx, stomach, intestines, rectum, and anus. Its function is heavily influenced by the exocrine glands: salivary glands, pancreas, and liver. The integrity of teeth declines and saliva production decreases; this impacts both the mechanical and chemical digestion of food. Weakness of the tongue or decreased coordination of swallowing muscles can lead to difficulty swallowing (dysphagia), which can impact both nutritional status and choking risk. Gastric acid secretion declines in the stomach, which increases the risk of ulcers and stomach inflammation (gastritis). Within the intestine, the normal folds (diverticula) can become impacted with feces, leading to inflammation (diverticulitis). The weakening of the anal sphincter may also lead to fecal incontinence. Within the liver, bile storage may increase, leading to a predisposition to gallstones with aging. The liver’s detoxifying abilities also slow, which is why increased monitoring via blood tests is used to adjust medication dosages. Genitourinary system: The genitourinary system includes the kidneys and urinary tract. Kidneys play a major role in detoxification and filtering medications and other digestive by-products. In older adulthood, they are not as efficient. This makes monitoring blood tests for kidney function particularly important in adjusting medication dosages. Kidneys also regulate electrolytes and water balance within the body. While kidneys function well into older adulthood unless disease is present, many older adults do not take in enough water, which can lead to dehydration. Musculoskeletal: The musculoskeletal system is made up of muscles, ligaments, tendons, bones, joints, and cartilage. With age, muscle mass declines (sarcopenia), which can lead to weakness and loss of function. Strength can be gained through specific exercises. Strengthening hand grip and extensors (triceps, glutes, and quadriceps) can be particularly important to preserving function, such as the ability to open jars, go up stairs, or get out of a chair independently. There is a faster decline in fast-twitch fibers, making quick or powerful movements difficult. Bone also loses density (osteopenia), and this loss is faster in postmenopausal women than in men due to hormonal differences. Cartilage in joints also wears down, leading to osteoarthritis, for which obesity is one of the greatest risk factors. Nervous system: The nervous system is made up of the central nervous system (brain and spinal cord) and peripheral nervous system (spinal nerves and autonomic nervous system). With age, the brain mass decreases, but this, in itself, does not appear to account for decreased nervous system function. Instead, nerve cells (neurons) begin to lose some of their structure and efficiency, leading to longer signal times. These longer signaling times can lead to decreased agility and responsiveness of muscles and organs. The nervous system function relies on signaling chemicals called neurotransmitters. Each has specific roles within the body. The neurotransmitters work in delicate balance with each other, and normal age-related changes in function appear to relate more to their imbalances, as opposed to the decline of a specific neurotransmitter. Mild memory loss and recall for recent events is a normal age-related finding, whereas dementia and long-term memory loss are pathological. Intelligence, as assessed by IQ (intelligence quotient), remains stable, although cognitive performance is often slower and more deliberate with age.Reflexes and senses are part of the nervous systems also. Postural reflexes to remain upright, as well as proprioception (sense of body position), and kinesthetic sensation (correctly sensing movement) diminish. This can impact balance, posture, and overall fine motor and gross motor control for independent locomotion and movement for daily activities.Endocrine system: This is a system of glands that secrete chemicals known as hormones. Hormones send signals to organs and tissues in the body to act in specific ways. A primary controlling structure to regulate most hormone release is the hypothalamus, which is part of the brain. The endocrine system operates under a fine-tuned set of signals throughout the body to maintain homeostasis. If the body can no longer self-regulate within pre-set norms, pathology or disease states occur. The endocrine system regulates body temperature, metabolic rate, growth and repair, blood sugar regulation, water and electrolyte regulation, and reproductive function. Some notable normal age-related changes within the endocrine system include:

Thyroid function decreases with age, which may partially account for decreased body temperature regulation, decreased metabolic rate, decreased fight or flight regulation, and increased incidences of cholesterol-induced atherosclerosis within the blood vessels.

Testosterone and estrogen both decline with age as well, impacting reproductive function and bone density.

Aldosterone is responsible for acting on the kidneys to regulate sodium and water. It decreases with age, therefore contributing to elevations in blood pressure.

Insulin, in and of itself, does not decrease. However, the body’s responsiveness to its signal does. This leads to insulin resistance and difficulty with blood sugar control. This is a major factor that makes type II diabetes more common after age 40.

Immune system: The immune system is quite complex and includes skin and mucous membranes, the thymus, and white blood cells. With age, immunity declines. The thymus gland actually deteriorates completely throughout the aging process. The overall decline in the immune function makes the older adult not only more susceptible to infection but also cancer and auto-immune disease. Integumentary system: This system refers primarily to the skin and its layers. With age, elastic components decrease, making wrinkles and unusual skin growths more common. Skin is also susceptible to UV damage over time, increasing the risk of skin cancer development. Deeper layers, like the calcaneal fat pad (in the heel), deteriorate, decreasing the cushioning within the feet; this can make foot pain that limits weight-bearing activity more likely. Sensory organs often receive their own special attention, as there is a separate medical specialist for each one. They include our eyes, ears, nose, mouth, and sensory receptors in the skin. Each has a declining function with age. The eyes lose visual acuity, which decreases the ability to see near objects (presbyopia), for which corrective lenses are often prescribed. Hearing decreases with age, with 1/3 of adults 65-70 having some impairment and 50% of adults over 70 having hearing impairment to some level. The most common type of hearing loss in older adults is called presbycusis. Both taste and smell decline with age as well, with the most notable taste deficit being in detecting amounts of salt. These declines contribute to both safety issues in properly identifying spoiled foods and also decreased desire for food.

Summary:
In summary, we have examined how each body system experiences normal age-related declines beginning in the third decade of life and persisting throughout the lifespan. These age-related changes add to the risk factors for chronic health conditions that develop later in life.

• Case Study
  You notice that your 90-year-old grandmother has been declining invitations to come to your home for dinner. She always deflects the invitation by inviting you to her home instead. While she does not have a driver’s license due to visual and cognitive agility challenges common with older age, there is a $2 ride-on-demand community transit system for older adults that she uses independently quite regularly. After a few months of noticing this pattern, you ask grandma why she always declines your invitations to dinner. At first, she says she doesn’t want to intrude and bother your routine. Then she notes that you are her grandkid, so it is her job to spoil you and cook for you; she loves to cook.Your intuition tells you there is something deeper, so you keep asking. She realizes you won’t stop asking, so she finally admits that she’s having trouble going up the five stairs to your home. Her home doesn’t have stairs. Her concern is quite common in the older population and may play into larger concerns such as voluntary self-isolation or avoiding activities that are located in places with stairs.Take a moment to outline the physiological reasons why it is often harder for older adults to go up stairs independently. Try to think of not just “bad knees,” but rather the age-related changes in each body system.Now that you have your outline, check your thoughts in comparison to sample answers:Cardiovascular: Going up stairs requires the heart rate to elevate to keep enough oxygen coming to the muscles through the blood flow. With age, it is harder for heart rate to elevate to meet demands. This is both due to decreased electrical conductivity, as well as decreased efficiency of the left ventricle to pump enough oxygenated blood with each contraction.Respiratory system: The body must process oxygen input and carbon dioxide output at a higher rate to go up stairs compared to walking on level surfaces. The main breathing muscle, the diaphragm, loses elasticity, becoming less efficient. Additionally, many older adults have some degree of kyphosis, which decreases useful lung capacity.Musculoskeletal system: Muscles undergo muscle wasting, sarcopenia with age. This weakens muscles. It takes more strength in the leg muscles to go up stairs as compared to level walking. Joint surfaces begin to wear down as well, contributing to age-related arthritis (osteoarthritis). When this involves the knees and hips, strength through increasing ranges of motion, such as going up stairs, can be painful and lead to avoidance.Nervous system: Reflexes, such as the postural righting reflex, to maintain upright positions and stay balanced are slower in older adults. This often leads to fear of falling, particularly on more challenging surfaces like stairs.Special senses: The vestibular sense for balance is part of the ear; these balance sensors show age-related functional decline. Vision also declines, and vision is 1/3 of the input for normal balance function. Stairs are a sequence of balancing on one foot, then the other. Adults with compromised senses are at greater fall risk when balancing on one foot, such as that needed to use stairs.If you are wondering why some older adults seem to go up stairs without limitations despite aging physiology, changes are partially genetic and partially environmental. Overall health status, as well as previous and current experience with exercise to slow physiological processes, both impact function. Many motivated older adults can regain a lost function with specific exercise or intervention to improve each contributing deficit. In this case, an orthopedic doctor consult to assess a possible need for a cane or other assistive device, physical therapy to improve balance and strength, and a vision consult may be part of the health care team utilized to help your grandmother improve her ability to use stairs.

References
Katch V, McArdle W, Kach F. (2011) Essentials of Exercise Physiology. 4th Ed. Wolters Kluwer: Philadelphia.Robnett RH, Brossoie N, Chop WC, Eds. Gerontology for the Health Care Professional. 4th Ed. Jones & Bartlett: Burlington, MA. 2020.Sazlina S. G. (2015). Health screening for older people-what are the current recommendations?. Malaysian family physician : the official journal of the Academy of Family Physicians of Malaysia, 10(1), 2–10.

Need to respond to the following:I feel that nervous system decline is the most profound impact on older adult function. Although this is a natural function that happens as you age, this is something that can be hard for most. Not everybody goes through it at the exact same time, but after a certain age, your brain function will decline. This will lead to short-term memory loss, losing verbal abilities, deterioration in intellectual performance, and even reacting on time and performing certain tasks would become affected by this (Maiese, 2022). All of these factors can lead to low self-esteem and depression. As well as feeling unworthy due to not being able to live life how you were used to. Also, feeling like a burden because you now need the help of others to be able to complete certain tasks. This is something that I see on a daily basis as a Paramedic in the Emergency Room. Sadly, I encounter many elderly patients that feel useless and embarrassed because they are a lot slower when trying to explain something, or because they need help to go to the bathroom. I have seen elderly patients become extremely frustrated because they feel as if they are being treated like a kid. Reference:Maiese, K. (2022, September). Effects of Aging on the Nervous System. Merck Manual. Retrieved from https://www.merckmanuals.com/home/brain,-spinal-cord,-and-nerve-disorders/biology-of-the-nervous-system/effects-of-aging-on-the-nervous-system