Organs of the Alimentary Canal

• Digestive System - specifically functions to ingest food, digests it into nutrient molecules, absorbs the nutrients into the blood-stream, and defecates it as wastes
• What are the two main organ groups of the digestive system?

  Alimentary Canal, Accessory Organs
• Alimentary Canal - performs the whole menu of digestive functions as it propels the foodstuffs along its length
• Accessory Organs - assist digestion in various ways
• What is the other term for Alimentary Canal?

  Gastrointestinal Tract
• What is the common or layman's term for Alimentary Canal?

  Gut
• Alimentary Canal - a continuous, coiled, hollow muscular tube that winds through the ventral body cavity from mouth to anus
• Mouth - where the food enters to the digestive tract
• Mouth - a mucous membrane-lined cavity
• What is the other term for the mouth?

  oral cavity
• Lips - protect the mouth's anterior opening from foreign objects and provide a surface for speech
• What is the other term for the lips?

  Labia
• Cheeks - forms the lateral walls of the mouth
• Hard Palate - forms the mouth's anterior roof
• Soft Palate - forms the mouth's posterior roof
• Uvula - a fleshy fingerlike projection of the soft palate, which dangles from the posterior edge of the soft palate
• Vestibule - it is the space between the lips and cheeks externally and the teeth and gums internally
• Lingual Frenulum - a fold of mucous membrane, which secures the tongue to the floor of the mouth and limits its posterior movements
• Pharynx - from the mouth, food passes posteriorly into here, which is also the common passageways for food, fluids, and air
• Esophagus - runs from the pharynx through the diaphragm to the stomach, which is essentially a passageway that conducts food to the stomach
• What are the four tissue layers that the alimentary canal organs are made up of?

  Mucosa, Submucosa, Muscularis Externa, Serosa
• Mucosa - the innermost layer, a moist mucous membrane that lines the hollow cavity of the organs
• Submucosa - found just beneath the mucosa
• Submucosa - a soft connective tissue containing blood vessels, nerve endings, mucosa-associated lymphoid tissue (MALT), and lymphatic vessels
• Muscularis Externa - a muscle layer typically made up of an inner circular layer and an outer longitudinal layer
• Serosa - the outermost layer of the alimentary canal walls
• What are the layers that the serosa is made up of?

  Visceral Peritoneum, Parietal Peritoneum
• Intrinsic Nerve Plexuses - are networks of nerve fibers that help regulate the motility and secretory activity of GI tract organs
• What are the two intrinsic nerve plexuses in the alimentary canal walls?

  Submucosal Nerve Plexuses, Myenteric Nerve Plexuses
• Stomach - is on the left side of the abdominal cavity, nearly hidden by the liver and diaphragm
• What are the different regions of the stomach?

  Cardia, Fundus, Body, Pyloric Antrum, Pylorus
• Cardioesophageal Sphincter - where the food enters the stomach from the esophagus
• Cardia - named for its position near the heart
• Fundus - the expanded part of the stomach lateral to the cardial region
• Body - is the midpoint of the stomach
• Greater Curvature - is the convex lateral surface of the stomach body
• Lesser Curvature - it is the concave medial surface of the stomach body
• Pylorus - the funnel-shaped and the terminal part of the stomach
• Pyloric Sphincter - part of the stomach that is continuous with the small intestine
• Chyme - after food has been processed in the stomach, it is thick like heavy cream, where it enters the small intestine through the pyloric sphincter