Anaphy Lab - Digestive System

• The digestive system provides the body with the nutrients essential for the health
• Food within this tube, the alimentary canal, is technically outside the body because it has contact only with the cells lining the tract.
• Before ingested food is available to the body cells, it must be broken down physically (chewing, churning) and chemically (enzymatic hydrolysis) into smaller diffusible molecules - a process called digestion.
• The digested end products can then pass through the epithelial cells lining the tract into the blood to be distributed to the body cells - a process termed absorption.
• The organs of the digestive system separated into two major groups: the alimentary canal, or gastrointestinal tract, and the accessory digestive organs.
• The alimentary canal consists of the mouth, pharynx, esophagus, stomach, small and large intestines, and anus.
• The accessory structures include the teeth and tongue, which participate in the mechanical breakdown of food; and the salivary glands, gallbladder, liver and pancreas, which release their products into the alimentary canal.
• Essentially the alimentary canal walls have four basic tunics (layers) namely: mucosa, the submucosa, the muscularis externa, and the serosa.
• The sublayers of mucosa is surface epithelium, lamina propria and muscle layer
• Surface epithelium


  Stratified squamous epithelium in the mouth, esophagus, and anus; simple columnar epithelium in the remainder of the canal.
• Surface epithelium

  Stratified squamous epithelium in the mouth, esophagus, and anus
• Surface Epithelium

  simple columnar epithelium in the remainder of the canal.
• Lamina propria


  Areolar connective tissue with blood vessels; many lymphoid follicles, especially as tonsils and mucosa-associated lymphoid tissue (MALT)
• MALT

  mucosa-associated lymphoid tissue (MALT)
• Muscle layer


  A thin layer of smooth muscle
• Surface epithelium


  Major Function: Secretion of mucus, digestive enzymes, and hormones; absorption of end products into the blood; protection against infectious disease.
• Submusoca

  No layer
• Surface epithelium

  Major Function: Secretion of mucus, digestive enzymes, and hormones; absorption of end products into the blood; protection against infectious disease.
• Submucosa


  Areolar and dense irregular connective tissue containing blood vessels, lymphatic vessels, and nerve fibers (submucosal nerve plexus)
• Submucosa


  Major Function: Blood vessels absorb and transport nutrients. Elastic fibers help maintain the shape of the organ.
• Submucosa

  Major Function: Blood vessels absorb and transport nutrients. Elastic fibers help maintain the shape of the organ.
• Muscularis externa

  It has two layers: Circular layer and Longitudinal layer.
• Circular layer


  It is a layer in the muscularis externa that is the inner layer of the smooth muscle
• Longitudinal layer


  It is a layer in the muscularis externa which is the outer layer of smooth muscle
• Muscularis externa


  It has two layers: Circular layer and Longitudinal layer.
• Muscularis externa


  Segmentation and peristalsis of digested food along the tract are regulated by the myenteric nervus plexus
• Serosa


  Visceral peritoneum
• Serosa


  Visceral peritoneum
• Serosa has one sublayer which is the Visceral peritoneum
• Visceral peritoneum


  Single layer of flat, serous fluid producing ceels
• Serosa


  Main function: Reduces friction as the digestive organs slide across one another.
• Serosa

  Main function: Reduces friction as the digestive organs slide across one another.
• Food enters the digestive tract through the mouth, or oral cavity.
• Within the mucosa-lined cavity are the gums, teeth, and tongue.
• The lips (labia) protect its anterior opening, the cheeks form its lateral walls, and the palate, its roof.
• The anterior part of the palate is called the hard palate because bone underlies it.
• The posterior soft palate is unsupported by bone, and the uvula, a fingerlike projection of the soft palate, extends inferiorly from its posterior edge.
• The muscular tongue occupies the floor of the oral cavity.
• A membrane, the lingual frenulum, secures the tongue to the floor of the mouth
• The space between the lips and cheeks and the teeth is the vestibule;