7. How may the weight of the bedclothes be removed from any particular part of the body? 8. How should a bedpan be cared for? 9. Describe in detail a day's routine either of yourself the last time you were ill in bed, or of another patient personally known to you. Could the plan of the day have been improved, and if so, in what ways? CHAPTER IX FEEDING THE SICK Substances used for food are generally grouped into three classes, called the three nutrients. The nutrients are: first, the proteids or nitrogenous substances, which are found in meat, fish, eggs, milk, cheese, peas, beans, etc.; second, the carbohydrates, which include sugars and starch; and third, the fats, which are found in butter, oil, the fat of meat, etc. In addition to the nutrients, water and certain mineral salts are essential to life, while some indigestible material like the fibre of vegetables is needed to give bulk and to stimulate the action of the intestines. The nutrients furnish the body with materials for growth, and for repair of tissues worn out by use; they also furnish fuel substances from which the body obtains its heat and its energy. All three nutrients can serve as fuel, but the proteids alone can furnish materials for growth and repair of tissues. In order to be used by the body for any purpose, nutrients must first go through a series of complicated changes known as digestion, which renders them soluble so that they can soak through the walls of the intestine. THE DIGESTIVE PROCESS Digestion begins in the mouth. There the food is crushed and its fibres separated by the teeth, it is moistened by the saliva, and substances in the saliva begin a chemical action upon the starch. Chewing should be sufficient to reduce the food to a soft mass well moistened with saliva. Slow eating is desirable, but the emphasis should be placed on thorough chewing. For instance, long intervals between bites are of no special benefit if mouthfuls of food are washed down by swallows of water. After it has been swallowed, the food passes into the stomach and remains there for a variable length of time, while it undergoes further preparation for absorption. It is moved about by the contraction of the muscular walls of the stomach, so that it becomes mixed with the stomach juices and more thoroughly softened. Some digestion of proteids goes on in the stomach, and a little absorption through the walls. Little by little the food is discharged from the stomach into the small intestine, and the most important part of digestion then begins. It is acted upon chemically by a fluid flowing into the intestine from an organ called the pancreas; this pancreatic juice acts upon all three nutrients and is of great importance in the digestive process. The bile and other juices that flow into the intestine perform important functions also.