L10 Structure of the esophagus and stomach
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Flashcard 1 (Remember):
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Front: List the four layers of the alimentary canal wall.
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Back: Mucosa, Submucosa, Muscularis Externa, Serosa (or Adventitia)1.
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Flashcard 2 (Understand):
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Front: Describe the epithelium found in the esophagus.
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Back: Non-keratinized stratified squamous epithelium2.
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Flashcard 3 (Apply):
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Front: What type of muscle is found in the upper, middle, and lower third of the esophagus?
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Back: Upper third: exclusively skeletal. Middle third: a combination of skeletal and smooth muscles. Lower third: exclusively smooth3.
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Flashcard 4 (Analyze):
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Front: How does the type of muscle in the muscularis externa of the esophagus relate to its function in swallowing?
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Back: The transition from skeletal to smooth muscle reflects the shift from voluntary initiation to involuntary completion of swallowing3.
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Flashcard 5 (Remember):
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Front: What type of glands can be found in the lamina propria of the esophagus near the stomach? What do they secrete?
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Back: Esophageal cardiac glands; mucus2.
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Flashcard 6 (Understand):
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Front: What is the difference between adventitia and serosa, and where are they found in relation to the esophagus?
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Back: Adventitia is loose connective tissue, while serosa is loose connective tissue covered with visceral peritoneum. The esophagus has adventitia, but the intra-abdominal part has serosa2....
II. Stomach
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Flashcard 7 (Remember):
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Front: Name the four regions of the stomach.
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Back: Cardia, Fundus, Body, Pylorus3.
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Flashcard 8 (Understand):
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Front: What is the significance of rugae in the stomach?
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Back: Rugae are large longitudinal folds formed by the mucosa and submucosa when the stomach is empty, and they disappear when the stomach is filled5.
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Flashcard 9 (Apply):
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Front: In which layers of the stomach wall would you find blood and lymph vessels?
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Back: Lamina propria, submucosa, and the connective tissue between muscle layers of the muscularis externa1....
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Flashcard 10 (Analyze):
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Front: How does the muscularis externa in the pylorus differ from that in the fundus and body, and what is the functional significance of this difference?
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Back: In the pylorus, the circular layer is greatly thickened to form the pyloric sphincter, which controls the emptying of the stomach contents into the duodenum5.
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Flashcard 11 (Remember):
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Front: What type of epithelium lines the stomach?
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Back: Simple columnar secretory epithelium5.
III. Gastric Glands
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Flashcard 12 (Remember):
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Front: List the parts of a gastric gland.
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Back: Short ducts, Isthmus, Neck, Body and base6.
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Flashcard 13 (Understand):
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Front: Describe the general structure of gastric glands.
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Back: Long, simple branched tubular glands located in the lamina propria6.
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Flashcard 14 (Apply):
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Front: If a patient has a condition that impairs the function of parietal cells, what specific substances would they have difficulty producing?
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Back: Gastric acid (HCl) and intrinsic factor7....
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Flashcard 15 (Analyze):
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Front: Explain the role of surface epithelial cells in protecting the stomach lining.
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Back: They secrete a thick mucus rich in bicarbonate ions, which neutralizes gastric acid (HCl)9.
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Flashcard 16 (Evaluate):
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Front: A patient's gastric biopsy shows an absence of parietal cells. What are the potential consequences and how would this be diagnosed?
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Back: Consequences: Achlorhydria and impaired vitamin B12 absorption. Diagnosis: Gastric acid secretion test and vitamin B12 level measurement8....
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Flashcard 17 (Create):
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Front: Design a schematic diagram illustrating HCl secretion by parietal cells, indicating the key molecules and transport mechanisms involved.
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Back: Diagram should include: CO2 and Cl- diffusion from blood, H2O combining with CO2 to form H2CO3, dissociation into bicarbonate (HCO3) and H+, active secretion of H+ to the lumen, and passive transport of Cl- to the lumen11.
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Flashcard 18 (Remember):
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Front: Name the cells found in the gastric glands.
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Back: Surface epithelial cells, Mucus neck cells, Parietal (oxyntic) cells, Peptic (chief) cells, Enteroendocrine cells, Stem cells9.
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Flashcard 19 (Understand):
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Front: What is the function of enteroendocrine cells in the gastric glands?
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Back: Secretion of hormones (mainly of paracrine action) such as serotonin, gastrin, and somatostatin12.
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Flashcard 20 (Apply):
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Front: How do peptic cells contribute to protein digestion in the stomach?
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Back: Secrete inactive pepsinogen, which is converted to pepsin in the acidic environment of the stomach10.
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Flashcard 21 (Analyze):
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Front: Compare and contrast the mucus secreted by surface epithelial cells and mucus neck cells.
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Back: Surface epithelial cells secrete a thick, highly alkaline mucus, while mucus neck cells secrete a soluble, less alkaline mucus7....
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Flashcard 22 (Remember):
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Front: Where are stem cells located in the gastric gland, and what is their function?
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Back: In the neck of the gastric gland; they proliferate to renew cells of the gastric glands12.
IV. Pylorus
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Flashcard 23 (Remember):
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Front: Describe the general characters of the pylorus of the stomach
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Back: Deep gastric pits occupying half the thickness of the gland, simple branched tubular but highly coiled pyloric glands, well-developed muscularis mucosa13.
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Flashcard 24 (Understand):
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Front: What is the function of the inner circular layer of the muscularis externa in the pylorus?
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Back: It is greatly thickened to form the pyloric sphincter, which controls the passage of chyme into the duodenum5....
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Flashcard 25 (Apply):
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Front: What cells are found in the pyloric glands?
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Back: Columnar mucus secreting cells, enteroendocrine cells (G-cells), few parietal cells, and stem cells13.
V. Gastroesophageal Junction
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Flashcard 26 (Understand):
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Front: Describe the changes that occur at the gastroesophageal junction.
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Back: Epithelium changes from stratified squamous to simple columnar, lamina propria becomes thicker, submucosa: esophageal glands stop gradually, muscularis externa becomes 3 layers (gets an inner oblique layer), and adventitia is replaced by serosa