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 principle function of the lung is to provide oxygen to the blood and in exchange rid the blood from carbon dioxide. The main cell types of the bronchioles are similar to that seen in the bronchus namely, basal cells, neuroendocrine cells,ciliatedcells, serous cells, Clara cells and goblet cells. Goblet and ciliated cells decrease in number as one approaches the terminal bronchioles, whereas the number of Clara cells increases proportionally. The Clara cells have a secretory function and represent the main progenitor cell after bronchiolar injury. They are columnar to cuboidal in shape and project above the ciliated cells into the airway lumen.
The pulmonary alveoli are demarcated by septa composed of a continuous layer of epithelial cells overlying a thin interstitium. Two morphologically distinct cells - typeIandtypeII (granular) pneumocytes (alveolar cells) line the alveoli. Alveolar macrophages are also present on the epithelial surface. The interstitium contains capillaries involved in gas exchange, as well as connective tissue and a variety of cells involved in alveolar shape and defense.
Type 1 pneumocytes cover approximately 95% of the alveolar septal surface. The nucleus is small and is covered by a thin rim of cytoplasm. The rest of the cytoplasm extends as a broad sheet over the alveolar surface. Adjacent type 1 pneumocytes are joined to one another by tight junctions that provide a barrier to the diffusion of water soluble substances into the alveolar airspace. Type 2 pneumocytes tend to be located near the alveolar intersections and exhibit a granular cytoplasm. Type 2 pneumocytes have several important functions, including the production of surfactant responsible for modifying alveolar surface tension. These cells also have the ability to be mitotically active and differentiate into type 1 cells, and synthesize substances such as fibronectin and α-1-antitrypsin that are involved in alveolar structure and defense, and enhancement of macrophage function.
