Understanding the Function and Structure of the GI Tract and Nutrition - Prof. Douglas N. , Study notes of Biology

Download Understanding the Function and Structure of the GI Tract and Nutrition - Prof. Douglas N. and more Study notes Biology in PDF only on Docsity! 9 March Objectives Know the function of the GI tract Understand what is involved with digestion Know the general structure of the GI tract Be able to correlate structure of the GI tract with function Understand the relationship between the GI tract and blood vascular system Nutritional Content of a Well-Balanced Diet Carbohydrates (330 g daily) – Main source of energy; fiber confers to many health benefits Protein (100 g daily) – Major structural building blocks Fat (75 g daily) – Energy storage; synthesis and repair of cell parts Water (2000 g daily) – Solvent; lubricant; medium for transport and temperature regulation Vitamins (<300 mg daily) – Enable chemical reactions in the body Minerals (5 – 10 g daily) – Aid enzyme function; electrical balance; generate nerve impulses; bone structure Functions Digestive System Move food through GI tract Mechanical/physical breakdown food Chemical breakdown food Absorption food particles and water Eliminate waste Digestion involves Secretion Absorption Motility Cell Specializations – Absorption and Secretion Secretory granules Cilia and microvilli Overview – GI tract 9 m/30 ft long hollow tube Accessory glands secrete substances into GI Digestion and absorption Small intestine Duodenum Jejunum Ileum Increase in Peyer’s patches (lymphoid tissue) the farther along the small intestine Figure 15.3 Figure 15.4 GI is designed to optimize absorption Figure 15.5