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Digestive gland. ---small digestive glands: gastric gland, intestinal gland … ---large digestive glands: salivary glands, pancreas, liver. General structure of Salivary glands. acinus. serous acinus: ---- structure: Serous secretory cells ----secretion: Watery fluid containing
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---small digestive glands: gastric gland, intestinal gland… ---large digestive glands: salivary glands, pancreas, liver
acinus • serous acinus: ---- structure: Serous secretory cells ----secretion: Watery fluid containing salivary amylase
b. mucous acinus: ----structure: mucous secretory cells ----secretion: viscous fluid containing mucus(glycoprotein)
c. Mixed acini and demilune the above two types of secretory cells serous demilune
Myoepithelial cells function:
intercalated duct • simple squamous epi. • simple cuboidal epi.
striated duct (secretory duct) • simple columnar epi. tall cell, acidophilic, round N, located at apical part • longitudinal striation:
General structure of Pancreas /exocrine portion /endocrine portion (pancreas islets ,secret hormones)
exocrine portion function: ----Consists of serous cells ----Without myoepithelial cells ----With several centroacinar cells in acinus cavity ----Long I.D. ,no S.D.
endocrine portion( pancreas islets) ---small spherical clusters composed of endocrine cells of pancreas
---EM: A cells • 20% • peripheral-distributed • function: secret glucogon B cell • 70% • centrally-distributed • function: secret insulin
D cells • 5% • distributed between A, B cells,have gap junction with A,B cells • function: PP cells
liver /hepatic lobule /portal area
Structure of classic hepatic lobule Central vein Hepatic plates a single layer of hepatocytes arranged radially around the CV. Hepatic cords
hepatocyte LM: • large ,20-30 um • polygonal, • eosinophilic (stains poorly because stored glycogen and fat are dissolved during preparation) • N: large, pale, round, centrally- located with obvious nuceulus,about 25% are binucleate
EM: Well-developed organells • Mitochondria: • RER: • SER: • Lysosome: • Golgi apparatus • Microbodies
hepatic sinusoid ----space between the hepatic plates
hepatic macrophage (Kupffer cell) macrophage in hepatic sinusoid Large granular lymphocyte
Perisinusoidal space (space of Disse) *fat-storing cell (Ito cell) ----irregular, with processes ----function: store the vitamin A, synthesis the collagen
bile canaliculus ----cell membrane of adjacent hepatocytes depress to form a tubular system between hepatocytes
* The three kinds of functional surfaces of hepatocytes ---contacting with adjacent hepatocyte ---facing the sinusoids through the Disse space ---forming a bile canaliculus
portal area interlobular artery: interlobular vein: interlobular bile duct: