Physiological changes during older adulthood 2nd

4. Changes in gastrointestinal system: The gastrointestinal system consists of the esophagus, the stomach, the small intestine, the large intestine or colon, the liver, gallbladder and the pancreas. Generally the physiological changes of an aging digestive system are minor.

Major gastrointestinal changes with aging 
  a. Increased prevalence of atrophic gastritis and achlorhydria.
  b. The liver is less efficient in metabolizing drugs and repairing damaged liver cells.
  c. Diverticulitis in the colon may cause pain.
  d. Reduced peristalsis of the colon can increase risk for constipation.

5. Changes in Urinary System: The urinary system includes the kidneys, ureters, urethra and bladder. It undergoes substantial changes in function as we grow older. In both men and women, urinary changes are often associated with changes in the reproductive system.



Urinary system changes with aging 
  a. Kidney mass decrease by 25-30 percent and the number of glomeruli decrease by 30 to 40 percent. These changes reduce the ability to filter and concentrate urine and to clear drugs.
  b. With aging, there is a reduced hormonal response and an impaired ability to conserve salt which may increase risk for dehydration.
  c. Bladder capacity decreases and there is an increase in residual urine and frequency. These changes increase the changes of urinary infections, incontinence and urinary obstruction.

6. Changes in Endocrine System: The endocrine system is a complex network of glandular tissues that secrete hormones directly into the blood which are used by target organs. The endocrine system controls a variety of important functions such as energy metabolism, reproduction and stress response.

Age-related changes in the endocrine system
  
  a. Insulin resistance may prevent efficient conversion of glucose into energy.
  b. A decrease in aldosterone and cortisol may affect immune and cardiovascular function.

7. Changes in Nervous System

  a. Older nerve cells may have fewer dendrites and some may become demyelinated which can slow the speed of message transmission. Most of these changes do not appear to affect ordinary activities of living.
  b. Decreased blood supply to the brain and loss of cells cause memory loss and confusion which may alter the personality of an older.
  c. The sense organs are functioning less than younger e.g. Hearing slowly declines, visual acuity also declines.
  d. The sense of taste and smell diminishes resulting in decreased appetite.
  e. Ability to respond to stimuli decreases which causes loss of sensation and perception.
  f. As people grow older, the rate at which they process information declines. Information processing has three phases

• Encoding: Getting information into the system. Encoding is particularly vulnerable to age. As we age it takes more time to encode information than when they were younger. This slower rate of encoding may be due to changes in our vision, hearing and other senses that reduce the efficiency of memory. The slower rate of encoding is most likely the reason for age-related declines in short-term memory.
• Storage: retaining information
• Retrieval: recalling information 

Two types of memory tasks are recall and recognition. Regardless of age, recognition is better than recall. recognition does not declines as we age, but recall does. Long-term memory may decline as we age depending on the extent to difficulty with encoding information. Very long-term memory which spans months or years is relatively stable until well after age 70.