On the welcome page of the dictionary, three major sections are shown: Normal tissues, Cancer and Cell structure. Below the image of each section are links to introductory texts for i) normal tissue histology, ii) hallmarks of cancer, and iii) cell structure overview. For the cancer-section there is also a link to current cancer statistics (incidence, survival, etc) for Sweden and the rest of the world. Within each section there are direct links to histology descriptions of different tissue types and tumor forms as well as descriptions of cell structures.
For the 'Tissue & cell types' and 'Tumor' sections, tissue-slides stained with hematoxylin and eosin (HE) are shown at three different levels of magnification. On the top level, an overview of the whole tissue-sample is shown with boxes in black indicating where zoomed-in representative parts of the tissue are available for viewing. Clicking on these boxes will zoom in on that part to show tissue structures, cells and features in greater detail. Throughout these sections, arrows indicate relevant tissue structures, cell-types and other features.
For the 'Cell structure' section, immunofluorescent images of formaldehyde-fixed cell lines are shown. The various cell structures that are demonstrated are always shown in the green channel using an antibody found in the Human Protein Atlas. The antibody name is linked to the subcellular location summary page of the target gene. The other channels: nucleus, microtubules and endoplasmic reticulum, are always shown in the blue, red and yellow channels, respectively. The channels can be toggled on and off by clicking on the respective coloured button above the image. When applicable, the immunofluorescent images are complemented by immunohistochemically stained cells where the location of the particular cell structure is shown in brown.
A common feature for all sections is that a general descriptive text about the tissue, tumor-type or cell structure is provided when browsing a particular topic.
The normal adult pancreas has a dual function and composition ? the exocrine component that produces enzymes necessary for digestion of food and the endocrine component, necessary for insulin production and regulation of blood glucose levels. The exocrine component is composed of lobular units of acini, that discharge their secretions into progressively larger ducts that finally merge into the mainpancreaticduct ? the duct of Wirsung and the accessory pancreatic duct of Santorini. The duct of Wirsung ends at the major duodenal papilla (papilla Vateri) and the duct of Santorini ends at a minor duodenal papilla.
The pyramidal-shaped acinarcells are large with their apical areas filled by markedly eosinophilic zymogen granules and the basilar cytoplasm is deeply basophilic. The acinar cells at the central portion of the acinus (centroacinar cells) fuse with the intercalated duct that fuses with the acinus. The intercalated ducts combine to form the intralobular ducts, which are lined by small cuboidal cells with pale cytoplasm. The intralobular ducts combine to form the interlobular ducts that are lined by mucin-secreting, tall columnar epithelium. The ducts of Wirsung and Santorini are lined by similar columnar epithelium with a greater proportion of goblet cells.
The Langherhans?islets, which constitute 1-2% of the cell mass in the adult pancreas, represent the endocrine component of the pancreas. These islets comprise a greater proportion of the pancreas at the time of birth. The islets are round, compact structures that are highly vascularised with sparse connective tissue. The diameter of islets is highly variable with an average of approximately 225?m. The main cell types in the islets are beta cells ? responsible for insulin production, alpha cells ? responsible for glucagon secretion, delta cells ? responsible for somatostatin secretion and PP cells ? the pancreatic polypeptide secreting cells.
