4/13/20 Nasopharynx Hard palate Mouth (oral cavity) Parotid gland Tongue Sublingual gland Salivary Soft palate Submandibular Oral glands gland cavity Uvula Lips (labia) Palatine tonsil Esophagus Pharynx Vestibule Lingual tonsil Stomach Pancreas (Spleen) Oropharynx Liver Lingual Gallbladder frenulum Transverse colon Epiglottis Duodenum Descending colon Tongue Small Jejunum Ascending colon intestine Ileum Laryngopharynx Large Cecum Hyoid bone intestine Sigmoid colon Esophagus Rectum Trachea Appendix Anus Anal canal (a) © 2018 Pearson Education, Inc. 1 © 2018 Pearson Education, Inc. 2 Nasopharynx Hard palate Upper lip Soft palate Oral Gingivae cavity Hard palate (gums) Uvula Lips (labia) Soft palate Palatine tonsil Vestibule Uvula Lingual tonsil Palatine tonsil Oropharynx Lingual frenulum Oropharynx Epiglottis Tongue Tongue Laryngopharynx (b) Hyoid bone Esophagus Trachea (a) © 2018 Pearson Education, Inc. 3 © 2018 Pearson Education, Inc. 4 Visceral peritoneum Intrinsic nerve plexuses • Myenteric nerve plexus Diaphragm • Submucosal nerve plexus Falciform ligament Lesser Liver omentum Submucosal glands Spleen Pancreas Gallbladder Stomach Duodenum Mucosa Visceral peritoneum Transverse • Surface epithelium colon • Lamina propria Greater omentum Mesenteries • Muscle layer Parietal peritoneum Submucosa Small intestine Peritoneal Muscularis externa cavity • Longitudinal Uterus muscle layer Large intestine • Circular muscle layer Cecum Rectum Serosa Anus (visceral peritoneum) Urinary bladder Nerve Gland in Lumen (a) (b) Artery mucosa Mesentery Vein Duct oF gland Lymphoid tissue outside alimentary canal © 2018 Pearson Education, Inc. 5 © 2018 Pearson Education, Inc. 6 4/13/20 Cardia Fundus Fundus Esophagus Muscularis externa Serosa • Longitudinal layer • Circular layer Body • Oblique layer Body Lesser Rugae of Rugae mucosa curvature of Pylorus mucosa Greater curvature Duodenum Pyloric Pyloric sphincter antrum Pyloric Pyloric (a) (valve) (b) sphincter antrum © 2018 Pearson Education, Inc. 7 © 2018 Pearson Education, Inc. 8 Gastric pits Pepsinogen Pepsin HCl Surface epithelium Pyloric sphincter pit Gastric Mucous Parietal cells neck cells Parietal cells Gastric Chief cells Gastric gland Gastric glands Chief cells Enteroendocrine (d) cell (c) © 2018 Pearson Education, Inc. 9 © 2018 Pearson Education, Inc. 10 Blood vessels serving the small intestine Right and leFt hepatic ducts from liver Cystic duct Lumen Common hepatic duct Muscle Bile duct and sphincter layers Circular folds Accessory pancreatic duct (plicae circulares) Villi Pancreas Gallbladder Jejunum Duodenal papilla Main pancreatic duct and sphincter Hepatopancreatic (a) Small intestine ampulla and sphincter Duodenum © 2018 Pearson Education, Inc. 11 © 2018 Pearson Education, Inc. 12 4/13/20 Absorptive Microvilli cells (brush border) Lacteal Villus Blood capillaries Lymphoid tissue Intestinal crypt (c) Absorptive Muscularis Venule cells mucosae Lymphatic vessel (b) Villi Submucosa © 2018 Pearson Education, Inc. 13 © 2018 Pearson Education, Inc. 14 LeFt colic Enamel (splenic) flexure Transverse Dentin Right colic mesocolon Crown (hepatic) flexure Pulp cavity Transverse colon (contains blood vessels and nerves) Haustrum Neck Descending colon Gum (gingiva) Ascending colon Cement IIeum (cut) Cut edge oF mesentery Root canal IIeocecal valve Root Teniae coli Periodontal membrane Sigmoid colon (ligament) Cecum Appendix Rectum Anal canal External anal sphincter Bone © 2018 Pearson Education, Inc. 15 © 2018 Pearson Education, Inc. 16 Foodstuff Enzyme(s) and source Site of action Foodstuff Enzyme(s) and source Site of action Starch and disaccharides Protein Digestion of Salivary amylase Mouth Digestion carbohydrates of proteins Pepsin (stomach glands) Stomach Pancreatic amylase Small intestine in the presence oF HCl Oligosaccharides* Large polypeptides and disaccharides Pancreatic enzymes Small intestine (trypsin, chymotrypsin, Brush border enzymes Small intestine Small polypeptides carboxypeptidase) Lactose Maltose Sucrose in small intestine (dextrinase, Small intestine glucoamylase, Brush border enzymes lactase, maltase, (aminopeptidase, Amino acids Galactose Glucose Fructose and sucrase) carboxypeptidase, (some dipeptides and dipeptidase) and tripeptides) The monosaccharides glucose, galactose, and Fructose Absorption of carbohydrates enter the capillary blood in the villi and are transported to the liver via the hepatic portal vein. Absorption Amino acids enter the capillary blood in the villi and are of proteins transported to the liver via the hepatic portal vein. *Oligosaccharides consist of a few linked monosaccharides. © 2018 Pearson Education, Inc. 17 © 2018 Pearson Education, Inc. 18 4/13/20 Ingestion Food Mechanical Foodstuff Enzyme(s) and source Site of action breakdown Pharynx • Chewing (mouth) Esophagus UnemulsiFied Fats • Churning (stomach) Propulsion Digestion • Segmentation EmulsiFied by the Small intestine • Swallowing of fats (small intestine) (oropharynx) detergent action • Peristalsis of bile salts From the liver Digestion (esophagus, stomach, Pancreatic lipase Small intestine small intestine, large intestine) Stomach Monoglycerides Glycerol and Absorption and Fatty acids fatty acids Lymph vessel Fatty acids and monoglycerides enter the lacteals oF the villi Absorption and are transported to the systemic circulation via the lymph Small of fats intestine in the thoracic duct. (Glycerol and short-chain Fatty acids are Blood Large vessel absorbed into the capillary blood in the villi and transported intestine to the liver via the hepatic portal vein.) Mainly H2O Feces Anus Defecation © 2018 Pearson Education, Inc. 19 © 2018 Pearson Education, Inc. 20 Bolus oF Food Tongue Uvula Pharynx Bolus Epiglottis Epiglottis up Upper down esophageal Glottis (lumen) sphincter of larynx Larynx up Esophagus Trachea Esophagus 2 Upper esophageal 1 Upper esophageal sphincter relaxed sphincter contracted © 2018 Pearson Education, Inc. 21 © 2018 Pearson Education, Inc. 22 Relaxed muscles Cardioesophageal sphincter open Bolus 3 Upper esophageal sphincter contracted 4 Cardioesophageal sphincter relaxed © 2018 Pearson Education, Inc. 23 © 2018 Pearson Education, Inc. 24 4/13/20 4 Secretin causes the liver to secrete more bile; Pyloric Pyloric Pyloric CCK stimulates valve valve valve the gallbladder closed slightly closed 1 Chyme entering to release stored opened duodenum causes bile and the duodenal entero- hepatopancreatic endocrine cells to sphincter to relax release cholecystokinin (allows bile from (CCK) and secretin. both sources to enter the duodenum). 2 CCK (red dots) and Peristaltic The most The secretin (blue dots) 1 Propulsion: 2 Grinding: 3 Retropulsion: 5 Stimulation waves move From the Fundus vigorous peristalsis and peristaltic wave closes the enter the bloodstream. by vagal nerve toward the pylorus. mixing action occur close pyloric valve, Forcing most of fibers causes to the pylorus. The pyloric the contents of the pylorus 3 Upon reaching the release oF end oF the stomach acts as backward into the stomach. pancreas, CCK induces pancreatic juice a pump that delivers small secretion oF enzyme- and weak amounts oF chyme into the rich pancreatic juice; contractions oF duodenum. secretin causes the gallbladder. secretion oF bicarbonate- rich pancreatic juice. © 2018 Pearson Education, Inc. 25 © 2018 Pearson Education, Inc. 26 Tryptophan Beans and other Methionine legumes Valine (a) Threonine Phenylalanine Leucine Corn and Isoleucine other grains Lysine (b) © 2018 Pearson Education, Inc. 27 © 2018 Pearson Education, Inc. 28 composed of 1 glycerol (a) Carbohydrates: polysaccharides, disaccharides; (b) Fats: composed of simple sugars (monosaccharides) molecule and 3 fatty acids; ATP triglycerides Cellular ATP Fats are the Glycogen and fat Metabolized uses Polysaccharides Lipid (fat) primary fuels Cellular uses broken down for by liver to Fatty in many cells ATP formation acetic acid, etc. GI digestion to acids GI digestion simple sugars To Excess stored as to fatty acids capillary glycogen or fat and glycerol Insulation and fat Fats build myelin cushions to protect sheaths and cell Broken down to glucose body organs membranes Monosaccharides and released to blood Glycerol © 2018 Pearson Education, Inc. 29 © 2018 Pearson Education, Inc. 30 4/13/20 polymers of amino acids (c) Proteins: (d) ATP formation (fueling the metabolic ATP formation if inadequate furnace): all categories of food can be ATP Carbon glucose and fats or if essential oxidized to provide energy molecules (ATP) dioxide Protein Normally amino acids are lacking Cellular infrequent Monosaccharides metabolic “furnace”: Water Functional proteins Citric acid cycle GI digestion to (enzymes, antibodies, Fatty acids and amino acids Cellular hemoglobin, etc.) uses electron transport Amino acids chain Structural proteins (amine first removed ATP (connective tissue fibers, Amino and combined with acids muscle proteins, etc.) CO2 by the liver to form urea) © 2018 Pearson Education, Inc. 31 © 2018 Pearson Education, Inc. 32 Glycogenesis: Glucose converted to glycogen and stored IMBALANCE Stimulus: Rising blood glucose level HOMEOSTATIC BLOOD SUGAR Stimulus: IMBALANCE Falling blood glucose level Glycogenolysis: Stored glycogen converted to glucose Gluconeogenesis: Amino acids and Fats converted to glucose © 2018 Pearson Education, Inc. 33.