Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 24, part 3 The Digestive System
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Gastric glands Parietal cells Intrinsic factor, and HCl Chief cells Pepsinogen Pyloric glands Mucous secretion containing several hormones Enteroendocrine cells G cells secrete gastrin D cells secrete somatostatin Histology of the stomach
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Stomach Lining Figure 24.13a, b
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Stomach Lining Figure 24.13c, d
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure Figure The Secretions of Hydrochloric Acid
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cephalic phase prepares stomach to receive ingested material Gastric phase begins with the arrival of food in the stomach Neural, hormonal, and local responses Intestinal phase controls the rate of gastric emptying Regulation of gastric activity
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.15a Figure The Phases of Gastric Secretion
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.15b Figure The Phases of Gastric Secretion
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.15c Figure The Phases of Gastric Secretion
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Preliminary digestion of proteins Pepsin Permits digestion of carbohydrates Very little absorption of nutrients Some drugs, however, are absorbed Digestion and absorption in the stomach
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-6 The Small Intestine and Associated Glandular Organs
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Important digestive and absorptive functions Secretions and buffers provided by pancreas, liver, gall bladder Three subdivisions: Duodenum Jejunum Ileum Ileocecal sphincter Transition between small and large intestine Small intestine
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.16a Figure Regions of the Small Intestine
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Plicae Transverse folds of the intestinal lining Villi Fingerlike projections of the mucosa Lacteals Terminal lymphatic in villus Intestinal glands Lined by enteroendocrine, goblet and stem cells Histology of the small intestine
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.17a Figure The Intestinal Wall
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.17b, c Figure The Intestinal Wall
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.17d, e Figure The Intestinal Wall
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Moisten chyme Help buffer acids Maintain digestive material in solution Intestinal juices
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Duodenal glands (Brunner’s glands) produce mucus, buffers, urogastrone Ileum aggregated lymphoid nodules (Peyer’s patches) Small Intestine
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Peristalsis Segmentation Gastroenteric reflexes Initiated by stretch receptors in stomach Gastroileal reflex Triggers relaxation of ileocecal valve Intestinal movements
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pancreatic duct penetrates duodenal wall Endocrine functions Insulin and glucagons Exocrine functions Majority of pancreatic secretions Pancreatic juice secreted into small intestine Carbohydrases Lipases Nucleases Proteolytic enzymes The pancreas
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.18a-c Figure The Pancreas