NR228 Nutrition

Let’s follow the path of a delicious ham and cheese sandwich with lettuce and pickles as it is eaten and digested! Start at the beginning and discuss the anatomical parts as well as the biochemical roles that contribute to this sand- wich being turned into chemical energy. Be sure to include mechanical and chemical mechanisms, along with how they are metabolized in the body!
What happens if one part does not function? For example, what happens to digestion if the person is missing many teeth but can’t afford dentures or perhaps has a digestive dis ?
1. 1  What stress factors may cause issues in the digestive tract for some people?
2. 2  How can a regular exercise program aid in the development of a healthy digestive tract?
3. 3  How might digestion and metabolism be different over the life span?
Digestion is the chemical breakdown of food molecules into smaller molecules that can be used by various cells within the body. The breakdown is initiated when food is ingested in the mouth and specific enzymes are exposed to components within the food molecules. Digestion begins in the mouth with mastication, or chewing, performed by the teeth. The purpose of chewing is to grant the food more exposure to enzymes, therefore allowing chemical diges- tion to occur faster. The presence of the food in the mouth stimulates exocrine glands. This causes the mouth to se- crete digestive enzymes, namely salivary amylase. These secreted enzymes aid in the breakdown of foods, officially starting the digestion process.
What happens if that part does not function? For example, what happens to digestion if the person is missing many teeth but can’t afford dentures, or perhaps has a digestive dis ?
There are several dilemmas involving digestion that the human body may encounter with progressed age, disease, or improper mechanics, such as lack of teeth. A major threat involving a decrease in digestion ability is malnutrition. Malnutrition does not simply refer to not eating, but also encompasses insufficient absorbance of nutrients once food has been eaten. There is a wide array of factors that may lead to malnutrition in an individual. Mechanically, the lack of teeth is a simple but yet common reason of decreased nutrition intake. Though salivary glands are stimulated upon the introduction of food to the mouth, a person with no teeth tends to avoid the more strenuous foods to chew, such as meats, carrots, lettuce, and nuts, and become partial to a lot of soft foods like potatoes and eggs, which may not necessarily be the most nutritious or balanced. Individuals with gum disease may have all their teeth, but it can become sore for them to chew their meals and, as a result, the eating dwindles. Jaw injuries or surgeries can cause discomfort and may temporarily hinder proper ingestion. This makes the digestion process more strenuous and time consuming on other organs.
What stress factors may cause issues in the digestive tract for some people?
The enteric nervous system, composed of millions of nerves, controls digestion. It communicated with the central nervous system. Stress has the ability to activate our ‘fight or flight’ response. In this mode, digestion can be slowed or shut down completely as blood flow is cut off by the central nervous system to focus energy on the perceived threat. In more nervous situations that are not threats, the body slows down digestion, which may cause abdominal cramps, grumbling, and gas. Stress factors include substance abuse, such as drugs and alcohol, work, school, and simply puberty. Also, the constant intake of pesticides and growth hormones from processed foods take a big toll on the digestive tract; the body does not receive the proper balanced nutrition. Constant stress can cause inflammation in the GI tract, and vice versa, constant GI tract problems cause increased levels of hormonal stress.
How can a regular exercise program aid in the development of a healthy digestive tract?
Exercise improves blood circulation throughout the entire body, including in our digestive systems. This motion aids in peristalsis and keeps food moving easily moving through the entire tract. This repels constipation, which also de- ters the possible chance of hemorrhoids, gas, bloating and cramps, even those sometimes associated with the men- strual cycle.
How might digestion and metabolism be different over the lifespan?
Aging is a factor in many digestive dis s; older adults are more prone to get digestive tract dis s because of medicines, antibiotics, and sometimes simply genetics. In the esophagus, the elderly tend to have impaired esophageal contractions. The movement of food is not impaired by this though, and the bolus can still easily reach the stomach. In the stomach, damage to the lining increases from the constant acidic environment, especially in adults who take aspirin. The risk for peptic ulcers increases. Also the stomach loses its elasticity over time and is not able to accommodate as much food. This is one of the reasons elderly people do not eat nearly as much, but still feel satisfied after meals. Not many changes occur regarding absorption in the small intestine. The commonly noted change is that lactase levels decrease, leading to lactose intolerance. Lastly, the rectum does somewhat enlarge in circumference, but the large intestine does not change much. Constipation can occur more frequently, mainly be- cause prescription drugs and antibiotics are used more frequently in older adults and elders.

References:
Grodner, Michele, Escott-Stump, S., Dorner, S. (2016). Nutritional Foundations and Clinical Applications: A Nurs- ing Approach, 6th Edition.
http://physrev.physiology.org/content/86/2/651