Elements of histology / by E. Klein.

  • Klein, E. (Edward) 1844-1925.
Date:
1889
Catalogue details

Licence: Public Domain Mark

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

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    alveoli of secreting and excreting glands, such as the kidney, liver, mammary giaud, testis and ovaiy, the salivary glands, mucous, peptic, and Lieberkiihn's glands, the sweat and sebaceous glands, the hair follicles, itc, consists of epithelial cells. Such is the case also with the sensory or terminal parts of tlie organs of the special senses. And, finally, epithelial cells occur in other organs, such as the thyroid, the pitui- tary body, &c. The hairs and nails, the cuticle of the skin, certain parts of the rods and cones of the retina, and the roJs of Corti in the organ of liearing, are modi- fied epithelial struc- tures. Epithelial cells are grouped together by exceedingly tliin layers of an albu- minous interstitial cement substance, which during life is of a semi-fluid nature, and belongs to the group of bodies known as globulins. IS. As regards sliape we distinguish two kinds of epithelial cells—columnar and squamous. The columnar cells are short or long, cylindrical or pris- matic, pyramidal, conical, club-shaped, pear-shaped, or spindle-shaped ; their nucleus is always more or less oval, their jjrotoplasm more or less longitudinally striated. On the free surface of the cells—i.e., the Fig. 15.—Various kinds of Epithelial Cells. A, Coluiunar cells of intestine; B, iioljhedrai cells ot tlie conjiiuctiva; c, ciliated conical cells of the trachea : D, ciliated cell of frog's nioiitli ; E, inverted conical cell of trachea; F, S(|ua]nous cell of Ihe cavity of mouth, seen from its broad surface ; G, squamous cell, seen eclgeways.