tailieunhanh - Lecture Discovering nutrition - Chapter 3: The human body: From food to fuel

Chapter 3 presents the following content: Taste and smell: the beginnings of our food experience, the gastrointestinal tract, overview of digestion: physical and chemical processes, overview of absorption, assisting organs, putting it all together: digestion and absorption, circulation of nutrients, signaling systems. | Chapter 3 The Human Body: From Food to Fuel Taste and Smell: The Beginnings of Our Food Experience Sight, smell, thought, taste, and sound Trigger a set of responses that prepare the digestive tract to receive food The Gastrointestinal Tract Variety of functions, including: Ingestion of food Transport of ingested food Secretion of digestive enzymes, acid, mucus, and bile Absorption of end products of digestion Movement of undigested material Elimination of digestive waste products The Gastrointestinal Tract Several layers to the GI tract, including Mucosa Circular muscle Longitudinal muscle Sphincters Overview of Digestion Physical movement Peristalsis Wavelike, muscular contractions Transport food and nutrients along the GI tract Segmentation Series of muscular contractions in the small intestines Divides and mixes the chyme Chemical breakdown Enzymes Proteins that catalyze chemical reactions Other secretions Acid Base Bile Mucus Overview of Digestion Overview of Absorption The road to nutrition absorption Passive diffusion Facilitated diffusion Active transport Assisting Organs Salivary glands Moisten food Supply enzymes Assisting Organs Liver Produces bile “Chemical factory” “Dynamic warehouse” Assisting Organs Gallbladder Stores and secretes bile Pancreas Secretes bicarbonate Secretes digestive enzymes Putting it All Together: Digestion and Absorption Mouth Enzymes Salivary amylase acts on starch Lingual lipase acts on fat Saliva Moistens food for swallowing Putting it All Together: Digestion and Absorption Esophagus Transports food to stomach Esophageal sphincter Putting it All Together: Digestion and Absorption Stomach Hydrochloric acid prepares protein for digestion and activates enzymes Pepsin begins protein digestion Gastric lipase has some fat digestion Gastrin (hormone) stimulates gastric secretion and movement Intrinsic factor is needed for absorption of vitamin B12 Putting it All Together: Digestion and Absorption Small intestine Sections of . | Chapter 3 The Human Body: From Food to Fuel Taste and Smell: The Beginnings of Our Food Experience Sight, smell, thought, taste, and sound Trigger a set of responses that prepare the digestive tract to receive food The Gastrointestinal Tract Variety of functions, including: Ingestion of food Transport of ingested food Secretion of digestive enzymes, acid, mucus, and bile Absorption of end products of digestion Movement of undigested material Elimination of digestive waste products The Gastrointestinal Tract Several layers to the GI tract, including Mucosa Circular muscle Longitudinal muscle Sphincters Overview of Digestion Physical movement Peristalsis Wavelike, muscular contractions Transport food and nutrients along the GI tract Segmentation Series of muscular contractions in the small intestines Divides and mixes the chyme Chemical breakdown Enzymes Proteins that catalyze chemical reactions Other secretions Acid Base Bile Mucus Overview of Digestion Overview of Absorption The .