ASGE Recognized Industry Associate (ARIA) Training Program OPEN | October 2024-2_GI Tract in Health_Esophagus

2_GI Tract in Health_Esophagus_Stomach

Pdf Summary

The gastrointestinal (GI) tract is a complex system responsible for the digestion and absorption of nutrients essential for growth, metabolism, body maintenance, and reproduction. It includes various organs such as the esophagus, stomach, small and large intestines, pancreas, liver, and gallbladder.<br /><br />Digestion involves breaking down food mechanically and chemically, starting from the mouth and progressing through other structures of the digestive system. Mechanical digestion includes processes like mastication (chewing), peristalsis (wave-like movements that propel food), and segmentation (mixing food with simultaneous contractions). Chemical digestion involves enzymes and acids such as saliva, gastric acid, pancreatic enzymes, and bile.<br /><br />The journey through the digestive tract begins in the mouth, where teeth and tongue help in the mechanical breakdown of food and saliva, produced by different salivary glands, initiates the digestion of carbohydrates and has antibacterial properties. The esophagus, a muscular tube approximately 18-26 cm in length, conveys these food boluses from the mouth to the stomach.<br /><br />The stomach is a J-shaped organ that acts as a reservoir, where food is mixed with acid and enzymes for further breakdown before moving to the small intestine. The stomach has distinct sections, including the fundus, body, pylorus, and cardia. Its lining, known as the mucosa, features rugae or gastric folds which allow expansion.<br /><br />The esophagus and stomach are lined with various muscular and epithelial cells, contributing to their structure and function. The gastroesophageal junction, including the lower esophageal sphincter, prevents the backflow of stomach contents into the esophagus.<br /><br />This summary captures fundamental aspects of the anatomy and physiology of the GI tract, from the mechanism of digestion to the structure and function of the esophagus and stomach.

Keywords

gastrointestinal tract

digestion

nutrient absorption

esophagus

stomach

mechanical digestion

chemical digestion

enzymes

peristalsis

gastroesophageal junction