<p> 12 Bio 104 Digestive System</p><p>Hole’s HAP [Chapters 17 & 18] </p><p>General Characteristics of the Alimentary Canal A. Functions 1. Ingestion -</p><p>2. Mechanical digestion -</p><p>3. Chemical digestion -</p><p>4. Propulsion -</p><p>5. Absorption -</p><p>6. Defecation -</p><p>B. Components of Digestive system 1. Alimentary canal (GI tract) -</p><p>2. Accessory organs -</p><p>C. Alimentary canal wall 1. Mucosa a. -</p><p>-</p><p> b.</p><p> c.</p><p>2. Submucosa -</p><p>-</p><p>3. Muscular layer -</p><p>- 13 Bio 104 Digestive System 4. Serosa - serous membrane</p><p>- adventitia</p><p>D. Movements of the Tube</p><p></p><p></p><p>E. Innervation of the Tube  Submucosal plexus</p><p> Myenteric plexus</p><p> Parasympathetic</p><p> Sympathetic</p><p>Mouth A. Functions </p><p></p><p></p><p></p><p>B. Parts of the Mouth</p><p>1. Cheeks and lips - - 14 Bio 104 Digestive System 2. Tongue - - papillae:</p><p> o filliform –</p><p> o fungiform –</p><p> o circumvallate -</p><p>- lingual fenulum</p><p> ankyloglossia</p><p>3. Palate</p><p>Hard palate -</p><p>Soft palate -</p><p>Uvula</p><p>4. Tonsils</p><p>- palatine</p><p>- lingual</p><p>- pharyngeal</p><p>5. Teeth Enamel –</p><p>Dentin –</p><p>Pulp cavity</p><p>Dentition formula: 3 2 1 4 1 2 3 Molars Premolars Canines Incisors</p><p>Secondary teeth 15 Bio 104 Digestive System 6. Salivary glands - 3 pairs: a. Parotid</p><p> b. Submandibular</p><p> c. Sublingual</p><p>- secretions of the salivary glands: a. Parotid</p><p> b. Submandibular</p><p> c. Sublingual</p><p>- Saliva a. Components . . electrolytes, buffers, glucoproteins, enzymes, wastes</p><p>.</p><p> b. Functions . moistens</p><p>. stimulates</p><p>. initiates </p><p>Pharynx A. Characteristics .</p><p>.</p><p>. 3 divisions: Nasopharynx</p><p>Oropharynx</p><p>Laryngopharynx 16 Bio 104 Digestive System B. Swallowing Mechanism . Soft palate, uvula, hyoid, larynx ______</p><p>. Epiglottis ______and closes off top of trachea</p><p>. Muscles:</p><p>- longitudinal muscle</p><p>- inferior constrictor muscles</p><p>. Peristaltic waves</p><p>C. Deglutition bolus =</p><p>1. Buccal</p><p>2. Pharyngeal</p><p>3. Esophageal</p><p>Esophagus A. Function o o B. Anatomy</p><p>Esophageal hiatus</p><p>Upper esophageal sphincter</p><p>Lower esophageal sphincter</p><p>C. Histology Mucosa</p><p>Submucosa</p><p>Muscular layer</p><p>Adventitia 17 Bio 104 Digestive System Stomach</p><p>A. Functions 1.</p><p>2.</p><p>3.</p><p>4.</p><p>B. Anatomy Features</p><p>4 regions:</p><p> rugae:</p><p>C. Gastric secretions 1. pepsinogen</p><p>2. pepsin</p><p>3. hydrochloric acid</p><p>4. mucus</p><p>5. intrinsic factor</p><p>Gastric pits:</p><p>Gastric glands: a) mucous cells </p><p> b) chief cells  </p><p> c) parietal cells   18 Bio 104 Digestive System D. Phases and regulation of gastric secretions  Phases 1. Cephalic</p><p>2. Gastric</p><p>3. Intestinal</p><p> Regulation of gastric secretions 1.</p><p>2.</p><p>3.</p><p>4.</p><p>E. Gastric Activities  Gastric Absorption</p><p> Mixing & emptying Chyme =</p><p>Rate of emptying:</p><p> Enterogastric reflex</p><p>F. Hormones</p><p>Gastrin –</p><p>CCK (cholecystokinin) –</p><p>Secretin – 19 Bio 104 Digestive System Accessory Organs: Pancreas, Liver, and Gallbladder</p><p>Pancreas A. Structure: head – body - tail – </p><p> pancreatic duct (Wirsung)</p><p> hepatopancreatic ampulla </p><p> hepatopancreatic sphincter </p><p>B. Histology 1. Pancreatic acini -</p><p>2. Pancreatic islets (Langerhans)</p><p> a) Alpha cells à ______BG levels</p><p> b) Beta cells à ______BG levels</p><p>C. Pancreatic Juice pancreatic amylase –</p><p> pancreatic lipase – </p><p> trypsin, chymotrypsin, and carboxypeptidase -</p><p> nucleases –</p><p> bicarbonate ions –</p><p>D. Regulation of secretions </p><p> 20 Bio 104 Digestive System Liver A. Anatomy Lobes – Ligaments –</p><p>Hepatic lobules –</p><p>Hepatic cells –</p><p>Hepatic sinusoids</p><p>Kupffer cells</p><p>Central veins</p><p>B. Bile ducts and bile Bile ducts:</p><p>______ ______ right & left ______</p><p> ______hepatic duct</p><p>Composition of Bile: water bile salts o o bile pigments cholesterol electrolytes</p><p>C. Liver Functions 1) CHO 2) Lipid 3) Protein 4) Storage 5) Removal 6) Detoxification 7) Synthesis 21 Bio 104 Digestive System</p><p>Gallbladder Regulation of bile release:</p><p>Stores and concentrates bile - releases bile --> cystic duct - stimulated by CCK between meals: hepatopancreatic sphincter around duodenal ampulla closes</p><p> after a meal: CCK is released  gall bladder to contract  relaxes hepatopancreatic sphincter</p><p>Small Intestine</p><p>A. Divisions: Duodenum, Jejunum, Ileum</p><p>Duodenum - -</p><p>Jejunum - -</p><p>Ileum - - -</p><p>B. Membranes</p><p>1. Peritoneum parietal visceral</p><p> retroperitoneal</p><p>2. Mesentery</p><p>3. Omenta Lesser Omentum Greater Omentum 22 Bio 104 Digestive System</p><p>C. Histology 1. Plicae circulares</p><p>2. Mucosa Intestinal villi –</p><p> mucosa à plicae à villi à epithelium à brush border ------> (increases surface area 600 times)</p><p>Each villus contains: a)</p><p> b)</p><p>3. Submucosa</p><p>4. Muscular layer</p><p>5. Serosa</p><p>D. Enzymes peptidase –</p><p> sucrase, maltase, lactase </p><p> lipase – breaks down ______à ______+ ______</p><p> enterokinase – converts ______to ______</p><p>E. Hormones CCK - - -</p><p>Secretin - - 23 Bio 104 Digestive System</p><p>F. Regulation of Intestinal Secretions   </p><p>G. Absorption in the Small Intestine  monosaccharides</p><p> electrolytes</p><p> fatty acids and glycerol</p><p>H. Movements in the S.I. • mixing movements • peristalsis – • segmentation – • overdistended wall triggers peristaltic rush resulting in ______</p><p>Large Intestine [cecum, ascending, transverse, descending, sigmoid colon; rectum, anus]</p><p>A. Cecum ileocecal valve – </p><p> vermiform appendix - vestigial part - -</p><p>B. Anatomical features haustra - diverticula - taenia coli - </p><p> epiploic appendages - </p><p> ascending, transverse, descending, sigmoid colon 24 Bio 104 Digestive System</p><p>C. Rectum - last 15 cm of GI tract - rectal columns - anus (anal orifice): terminal 2-3 cm - internal anal sphincter - external anal sphincter </p><p>D. Large Intestine Wall Mucosa - lack of villi - lots of goblet cells - intestinal glands Submucosa</p><p>Muscular Layer</p><p>Serosa</p><p>E. Functions of the Large Intestine -little or no digestive function -absorbs water and electrolytes -secretes mucus -houses intestinal flora -forms feces -carries out defecation G. Movements of L.I.</p><p>H. Feces - water, electrolytes, mucus</p><p>- bacteria</p><p>Color: bile pigments altered by bacteria </p><p>Odor - produced by bacterial compounds 25 Bio 104 Digestive System</p><p>Digestion and Absorption A. CHO digestion</p><p>B. Lipid Digestion</p><p>C. Protein Digestion</p><p>D. Water Absorption</p><p>Life Span Changes</p><p>Clinical Disorders</p>