The Digestive System

Functions of the Digestive System  Ingest food  Break down food Digestion  Physical  Chemical  Absorb nutrients  Eliminate non-digestible waste

Anatomy of the Digestive System  Alimentary canal  Accessory organs

Anatomy of the Digestive System  Oral Cavity Tongue  Skeletal muscle  Papillae  Frenulum Hard palate Soft palate  Uvula

Anatomy of the Digestive System  Oral Cavity Salivary glands  Saliva Amylase Moistens Lysozyme and antibodies

Anatomy of the Digestive System  The Pharynx  Swallowing Voluntary phase Reflex action – once food or drink is pushed back to the oropharynx

Anatomy of the Digestive System  The Esophagus Muscular tube Peristalsis Esophageal sphincter

Anatomy of the Digestive System  The Wall of the Alimentary Canal Mucosa  Epithelium  Glandular cells  Goblet cells Submucosa  Loose connective tissue

Anatomy of the Digestive System  The Wall of the Digestive Tract Muscularis Serosa  squamous epithelium Or Adventitia  Connective tissue

Anatomy of the Digestive System  The Stomach J-shaped organ Regions Rugae Storage  proteins

Anatomy of the Digestive System  Peritoneum Parietal Visceral

Anatomy of the Digestive System  The Small Intestine Regions  Duodenum Glands secrete mucus Receives pancreatic secretions and bile  Jejunum  Ileum

Fig

Anatomy of the Digestive System  Wall of the Small Intestine Circular folds Villi Microvilli

Anatomy of the Digestive System  The Large Intestine Cecum  appendix Colon Rectum Anal canal

Anatomy of the Digestive System  Feces Three-quarters water One-quarter solids  Bacteria  Fiber and other indigestible remains

Accessory Organs of Digestion  Pancreas Endocrine  pancreatic islets insulin Glucagon Exocrine  Pancreatic juice

Accessory Organs of Digestion  The Liver Structure  Two main lobes  Bile ducts form common hepatic duct

Accessory Organs of Digestion  The Gallbladder Store bile Bile small intestine