Elements of histology / by E. Klein.

  • Edward Emanuel Klein
Date:
1884
Catalogue details

Licence: Public Domain Mark

Credit: Elements of histology / by E. Klein. Source: Wellcome Collection.

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    portant function of columnar epithelial cells—viz., I the formation of mucus. In mucus-secreting I glands all the epithelial cells have this function permanently, but in ordinary columnar epithelium only a comparatively small number of the cells, as a rule, undergo this change, and then only { temporarily; for a cell subject to it at one time may shortly afterwards resume the original shape and aspect of an ordinary protoplasmic, cylindrical, or conical epithelial cell, and vice versa. If ciliated cells undergo this change, the cilia are generally first detached. It can be shown that in this change of an ordinary columnar epithelial cell into a goblet cell, the inter- I stitial substance of the cell reticulum increases in I amount, the meshes enlarging and distending the body of the cell. The interstitial substance probably under- goes the change into mucin, 26. PricRle Cells (Fig.U).—Amongst the middle and deeper layers of the stratified pavement epithelium, such as is present in the epidermis and on the surface i of the oral cavity and pharynx, we meet with a close, j more or less distinct and regular striation, extending ! from the margin of one cell to that of each of its I neighbours, by means of fine transverse short fibrils I which, passing from protoplasm to protoplasm, connect the surfaces of the cells, 27. Pigmented epithelial cells—-i.e., epithelial cells filled with black pigment particles (crystals)—are found j on the internal surface of the choroid and iris of I the eyeball. In coloured skins, and in coloured patches of skin I and mucous membrane, such as occur in man and animals, pigment in the shape of dark granules is found in the protoplasm of the deeper epithelial cells, as well as in branched cells situated between the epithelial cells of the deeper layers. Minute
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