Ch. 43 offers a comprehensive overview of the gastrointestinal system, covering its fundamental structures and functions, including associated organs like the liver and pancreas. It details the key processes of ingestion, digestion, absorption, and elimination, highlighting the roles of various organs and secretions. The text also discusses the impact of aging on the digestive system and provides a guide to subjective and objective assessment methods, including physical examination techniques and various diagnostic studies, such as imaging and endoscopic procedures. Finally, it touches upon common assessment abnormalities and the nursing responsibilities associated with different tests.