16 Digestive Glands

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16 Digestive Glands

• I. Salivary Glands
• II. Pancreas
• III. Liver

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I. Salivary Glands

• Serous glands
• Mucous glands
• Seromucous glands
• Ducts
• 16-1

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I. Salivary Glands

• A. Serous cells (16.1)
• 1. pyramidal shape
• 2. spherical nucleus
• 3. tight junctions, intermediate junctions,
  desmosomes, gap junctions

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I. Salivary Glands

• A. Serous cells (16.2,16.4)
• 4. protein synthesis (basophilic)
• 5. acinus

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I. Salivary Glands

• B. Mucous cells (16.1)
• 1. cuboidal to columnar
• 2. nucleus flattened at base
• 3. pale staining cytoplasm

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I. Salivary Glands

• B. Mucous cells
• 3. lightly stained cytoplasm (16.4,16.5)
• 4. tubular gland

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I. Salivary Glands

• TEM of mixed seromucous acinus 16-3

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I. Salivary Glands

• C. Ducts
• 1. intercalated ducts (16.1)

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I. Salivary Glands

• C. Ducts
• 2. striated (intralobular) ducts (16.1,4.24)
• a. basal infoldings
• b. mitochondria
• c. ion-transporting cells
• d. diagnostic feature of salivary glands

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I. Salivary Glands

• C. Ducts
• 3. interlobular (excretory) ducts (16.5)
• a. stratified cuboidal/columnar
• b. leads to oral cavity

http//www.kumc.edu/instruction/medicine/anatomy/h
istoweb/gitract/gitract.htm
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I. Salivary Glands

• D. Parotid gland
• 1. branched acinar gland
• 2. all serous cells
• E. Submandibular gland
• 1. branched tubuloacinar gland
• 2. serous gt mucous cells
• F. Sublingual gland
• 1. branched tubuloacinar gland
• 2. mucous gt serous cells
• 3. serous demilunes 16-4
• G. Unnamed Salivary Glands

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II. Pancreas

• A. Structure
• 1. thin capsule
• 2. septa separate lobules
• B. Endocrine portion
• 1. islets of Langerhans

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II. Pancreas

• C. Exocrine portion
• 1. compound acinar gland (16.6,16.7)
• 2. similar to parotid lacks striated ducts
• 3. intercalated interlobular ducts
• a. columnar epithelium

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II. Pancreas

• TEM of pancreatic acinar cell 16-9

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II. Pancreas

• D. Histophysiology
• 1. protein synthesis (basophilic)
• 2. secretes digestive enzymes (acidophilic)
• 3. secretion controlled by enteroendocrine
  cells of duodenum

http//www.lab.anhb.uwa.edu.au/mb140/CorePages/Liv
er/Images/pan20he.jpg
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III. Liver

• A. Structure overview
• 1. blood supply
• a. hepatic portal vein
• b. hepatic artery
• 2. stroma
• a. thin capsule
• b. reticular fibers
• 3. parenchyma
• a. hepatocytes
• b. liver lobules

http//www.transplantlife.com/img/liver.jpg
http//arbl.cvmbs.colostate.edu/hbooks/pathphys/di
gestion/liver/histo_loblow.jpg
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III. Liver

• Reticular fiber stroma shown with silver stain
  16-13.

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III. Liver

• B. Liver lobule
• 1. polygonal shape (16.11)
• 2. central vein
• a. leads to hepatic vein

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III. Liver

• B. Liver lobule
• 3. hepatic cords (16.12,16.13)
• a. radially arranged around central vein

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III. Liver

• B. Liver lobule
• 4. liver sinusoids (16.12,16.14)
• a. between hepatic cords
• b. Kupffer cells (macrophages)
• 1) old rbcs

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III. Liver

• B. Liver lobule
• 5. space of Disse (16.18.16.21)
• a. between endothelial cells and hepatocytes

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III. Liver

• LM of space of Disse 16-15

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III. Liver

• B. Liver lobule
• C. Portal triads (16.11)
• 1. location peripheral to lobule
• 2. 3-6 per lobule

http//www.udel.edu/Biology/Wags/histopage/colorpa
ge/clg/clgllp.GIF
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III. Liver

• C. Portal triad (16.13)
• 3. br. of portal vein
• a. blood from sup. inf. mesenteric,
  splenic veins
• b. empties into sinusoids
• 4. br. of hepatic artery
• a. oxygenated blood from celiac trunk of
  aorta
• b. empties into sinusoids
• 5. br. of bile duct system
• a. simple cuboidal epithelium

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III. Liver

• D. Hepatocytes (16.18)
• 1. geometric shape
• 2. 20-30 mm diameter
• 3. spherical nucleus
• 4. eosinophilic cytoplasm
• a. mitochondria
• b. sER ( rER)

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III. Liver

• TEM of hepatocyte 16-22
• Note the organelles

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III. Liver

• D. Hepatocytes
• 5. bile canaliculi
• a. between adjacent hepatocytes
  (16.20,16.21)
• b. 1-2 mm diameter
• c. flow into bile ductule/duct at triad

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III. Liver

• D. Hepatocytes
• 5. bile canaliculi (16.19)
• d. tight junctions at boundaries