Small Intestine

• How long is the small intestine?

  5 meters long
• What do you call the site where the digestive processes are COMPLETE and NUTRIENTS are ABSORBED?

  Small Intestine
• What are the 3 segments of small intestine in order?

  Duodenum, jejunum, and ileum
• Plicae circulares: series of permanent CIRCULAR or SEMILUNAR folds
• Plicae circularis is best developed where?

  jejunum
• Villi: a short (0.5-1 mm) mucosal outgrowths which is finger-like or leaf-like
• Villi is covered with what type of epithelium?

  Simple columnar epithelium
• Crypts of Lieberkuhn: opening of the tubular glands found between the VILLI
• What is this?

  Small intestine

  
• Label:

  A) Villi

  B) Plicae circulares

  C) Submucosa

  D) Mucosa

  E) Serosa

  
• What are the different INTESTINAL CELLS?

  Absorptive cells, Goblet cells, Enteroendocrine cells or APUD cells, Duodenal (Brunner) Glands, Undifferentiated cells, and Paneth cells
• APUD means?

  Amine Precursor Uptake and Decarboxylation
• What is the MOST COMMON intestinal cells?

  Absorptive cells
• Absorptive cells: tall and columnar with a prominent striated (brush) border of microvilli
• Absorptive cells: has a THICK GLYCOCALYX COAT
• Thick glycocalyx coat: cover and protect microvilli from corrosive digestive chemicals
• Goblet cells are located in what epithelium?

  columnar
• What intestinal cells are MORE NUMEROUS in ILEUM?

  Goblet cells
• Enteroendocrine cells: scattered in epithelium of the Villi and intestinal glands
• What intestinal cells secrete numerous regulatory hormones for digestive systems?

  enteroendocrine or APUD (amine precursor uptake and decarboxylation) cells
• Duodenal or brunner glands are found where?

  submucosa of duodenum
• Duodenal (brunner) glands: branched, tubuloacinar glands with light-staining mucous cells
• DUCTS OF DUODENAL GLAND: penetrate the muscularis mucosae and discharfe secretory products of the base of intestinal glands between the villi
• What cells are the base of intestinal glands?

  Undifferentiated cells
• What intestinal cells functions as STEM CELLS and increase MITOTIC ACTIVITY?

  Undifferentiated cells
• What intestinal cells are PYRAMID-SHAPED with large, acidophilic/eosinophilic granules in their cytoplasm?

  paneth cells
• What layer of small intestine has LARGER BLOOD VESSELS and LYMPH VESSELS?

  Submucosa
• Submucosal or Meissner nerve plexus: controls mainly gastrointestinal secretion and local blood flow
• What nerve plexus is found in muscularis?

  Myenteric or Auerbach nerve plexus
• Myenteric or Auerbach nerve plexus: responsible for gastrointestinal movements
• Peyer Patches: numerous aggregations of closely packed PERMANENT lymphatic nodules
• What occupies a LARGE PORTION of the LAMINA PROPRIA and SUBMUCOSA?

  Wall of ileum
• What do you call the HIGHLY SPECIALIZED epithelial cells that cover the Peyer patches?

  M cells
• M cells have what instead of microvilli?

  microfolds
• M cells: phagocytes luminal antigens and transports them into lymphocytes and macrophages which is then stimulated to produce specific antibodies against antigens.