Clear, Detailed, And Exam-Ready Nursing Notes On Digestive System

DIGESTIVE SYSTEM Major functions of digestive system Ingestion- Process by which food enters our body through the oral cavity. Secretion- Release of enzymes, acids, water, buffers and salts in the digestive tract which aids indigestion and absorption. Mechanical processing - Physical breakdown of food to make the food easy to pass through the digestive tract. Digestion- Chemical breakdown of food into smaller pieces which is easier for absorption. Absorption- The process by which the end products of digestion are taken up from the gastrointestinal tract (GI) into the blood or lymph for use by the body. Defecation- Elimination of waste products or indigestible substances from the body. Structure of the GI tract Has four layers 1. Mucosa Innermost layer Consist of an epithelium Secretes mucus and enzymes and absorbs nutrients 2. Submucosa Irregular connective tissue Mainly has the nerves, blood vessels and the lymphatics 3. Muscularis External Has smooth muscle cells. The inner circular layer is essential for formation of valves. The outer longitudinal layer is essential for moving materials along the digestive tract. 4. Serosa Outermost protective layer Helps to reduce the friction with other organsKey and accessory organs Food does not directly pass through the accessory organs but