. Text-book of normal histology: including an account of the development of the tissues and of the organs. nnective-tissue framework ofthe organ divides the glandular tissue intolobes, which are subdivided by septa intothe lobules, these, in turn, being com-posed of groups of acini. The laminatedfibrous connective tissue constituting thewalls of the pancreatic duct is clothed bya single layer of columnar branches of the main duct divide atonce into the long intermediate tubules,the intralobular ducts, or salivary tubes,being wanting ; it follows that the vertical striatioh of th
. Text-book of normal histology: including an account of the development of the tissues and of the organs. nnective-tissue framework ofthe organ divides the glandular tissue intolobes, which are subdivided by septa intothe lobules, these, in turn, being com-posed of groups of acini. The laminatedfibrous connective tissue constituting thewalls of the pancreatic duct is clothed bya single layer of columnar branches of the main duct divide atonce into the long intermediate tubules,the intralobular ducts, or salivary tubes,being wanting ; it follows that the vertical striatioh of the epithelium lining these tubes, so conspicuous in sectionsof the parotid gland, is absent in the pancreas. The cylindrical cells of the larger ducts gradually pass into thelower cuboidal and flattened plates lining the intermediate acini of the pancreas are more tubular than those of the parotidgland, while the secreting cells suggest more strongly the cylin-drical or pyramidal type than those of the salivary gland ; thesecells are further characterized by the presence of a zone, next the. Section of human pancreas, in-cluding several acini and two ducts :the cells present a central granularand a peripheral clear zone. 186 NORMAL HISTOLOGY. Fig lumen of the acinus, containing numbers of highly refracting par-ticles, while the peripheral outer half of the cells contains the nucleusand is comparatively free from the granules. The relations, how-ever, between the clear and granular zone of the pancreatic cells arenot constant, but vary with the condition of functional the earliest stages of digestion, when the cells are filledwith secretion, the clear zone occupies almost the entire cell, thegranules being confined to a narrow belt immediately around thelumen; towards the close of a period of functional activity, on thecontrary, the granules occupy the greater part of the cell, whilethe clear zone is reduced to a narrow peripheral area ; during fasting
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