DIGESTIVE SYSTEM

Cards (13)

  • Mucosal wall architecture
    • Mouth
    • Tongue
    • Salivary Glands
    • Pharynx
    • Stomach
    • Small Intestine
    • Large Intestine
    • Pancreas
    • Liver
  • Tongue
    • Muscular organ that occupies the floor of the oral cavity
    • Facilitate speech, mastication (chewing), and assists in swallowing
    • Responsible for sense of taste
  • Salivary Glands
    • Lubricate the mouth
    • Allows you swallow
    • Aids in digestion
    • Protection
  • Major Types of Salivary Glands
    • Sublingual
    • Submandibular
    • Parotid
  • Pharynx
    • Bolus passes through from the mouth
    • Deglutition-swallowing
    • Epiglottis- reflexively covers the glottis (opening of the trachea; creates a ramp to direct the bolus into the esophagus)
  • Stomach
    • Mechanical and chemical digestion are increased
    • Gastric rugae, these folds accommodate the expansion of the organ
    • Cardia- attachment of the esophagus to the stomach
    • The tissue from epithelium that resist friction becomes epithelium that resists the harsh chemical environment
  • Categories of Cells in the Stomach
    • SLC- surface lining cells, line the luminal surface of the stomach; tight junction complexes from adjacent cells creating a watertight barrier
    • Parietal cells- HCL- producing cells
    • Zymogenic cells (gastric chief cells)- secrete an enzyme-rich mixture; pepsinogen
    • Enteroendocrine cells- hormones response to stomach activity
  • Divisions of the Stomach
    • Cardia- gastric glands rich in mucus producing cells protect against the harmful acid
    • Fundus- densely populated with parietal cells
    • Pylorus- mucus-produce cells that neutralize the stomach acid
    • Pyloric sphincter – regulates the passage of material
  • Small Intestine
    • 20 ft long
    • Digested materials are absorbed into the blood and lymphatic system
    • Plicae circularis- are circular folds found in duodenum and jejunum; they are covered with villi-microvilli where absorptive cells are located
    • Intestinal villi- vascular and have lymphatic vessels
    • Ileum, final segment which produces a variety of enzymes and agents such as lysozyme and several immune system cytokines that are essential for immune system
  • Cell Types in the Small Intestine
    • Surface absorptive cells- numerous microvilli to absorb material from intestinal lumen
    • Goblet cells- mucus secreting cells become more abundant in the mucosal lining
    • Enteroendocrine cells- produce hormones; produce gastric inhibitory peptide; produce cholecystokinin
  • Large Intestine
    • 5ft in length, 3 inches in diameter
    • Mostly absorb water (approx. 1400 ml per day)
    • Compacts the material into solid waste (feces; 100 ml/day)
    • Muscular sphincter (Ileocolic valve), allows food from small intestine to large intestine
    • Spasmodic contraction- helps move the fecal material father along the colon
    • Rectum- the final segment of the colon is the rectum which functions for the storage of feces and its elimination(defecation)
    • Two muscular sphincters: internal anal sphincter is under involuntary and is always in a state of contraction and external sphincter is voluntary and is made up of skeletal muscle
  • Pancreas
    • Accessory digestive gland
    • Exocrine secretion pass through the pancreatic duct into common bile duct and enter to duodenum
    • Pancreatic cells secretes a solution of digestive enzymes (pancreatic juice) to further degrade carbohydrates, proteins, and fats
  • Liver
    • Blood from digestive tract is brought to the liver via hepatic portal vein; this nutrient-rich blood is spread throughout the open spaces of the liver and forced to make contact with hepatocytes to metabolize the material
    • Blood-filtering
    • Bile-producing (breakdown fats into fatty acid)
    • Storage facility of carbohydrate and vitamins (A, D, B)
    • Fats are metabolized and regulated