Normal histology : a manual for students and practitioners / by John R. Wathen.

  • Wathen, John Roach, 1872-
Date:
[1905]
Catalogue details

Licence: In copyright

Credit: Normal histology : a manual for students and practitioners / by John R. Wathen. Source: Wellcome Collection.

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    III. Modified Epithelium: a. Ciliated.—Tliis variety is limited to the most superficial layer of columnar cells, if stratified, and consists of delicate, hair-like processes on the outer end or free surface of the cell. These cilia are modifications of the eell-proto])lasm, and when carefully studied by special methods of staining are found to be made up of an outer layer of hair-like proc- esses, next a cuticular layer, with a row of basal e/ramdes immediately below this, and lastly a series of fine threads converging tow^ard the nucleus of the cell. These last make up the fibrillar structure of the protoplasm. It occurs prin- cipally in the respiratory tract, w here the cilia are supposed to Fig. 13. Ciliated columnar epithelium (stratified) from trachea, showing ciliary wave. (Nichols and Vale.) remove small particles of dust by keeping up a vibration or sweep centrifugally toward the nose. b. Goblet.—Between the columnar cells of the most super- ficial layer of columnar epithelium, if stratified, lining mucous surfaces, are found elliptical cells resembling goblets, and containing mucus, which is discharged upon the outer surface of the epithelium. These cells are sometimes called unicel- lular f/lands, or gland-cells. They are distinguished from the other cells by their larger size and clear protoplasm. This type occurs in all mucous membranes, especially in the intes- tinal tract. c. Pigmerded.—When epithelial cells eontain a coloring-