Gastrointestinal Physiology

Gastrointestinal physiology is the study of the functioning of the digestive system. It covers the motility and secretions of the stomach and intestines, the absorption and digestion of nutrients, and the regulation of fluid and electrolyte balance. Gastrointestinal motility is the coordinated contraction of the smooth muscles of the digestive tract. This allows food to move through the digestive tract. The process is regulated by hormones and the autonomic nervous system. Gastrointestinal secretions involve different hormones, enzymes and mucus that help to break down food and absorb nutrients. Gastric acid, bile, and pancreatic juices are secreted by the stomach, gallbladder and pancreas, respectively. These secretions help to break down food, allowing the body to absorb nutrients. Absorption is the process by which nutrients are taken up by the digestive tract and transported to other parts of the body. This is facilitated by the tiny fingerlike projections, called villi, that line the small intestine. Nutrients are absorbed through the villi into the bloodstream and transported to other parts of the body. Fluid and electrolyte balance is important for the maintenance of normal body functions.