. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. A section of a minutely injected piece of human lung. (After Rainey.) The section cuts longitudinally a branching bronchial tube. At a, the ciliated epithelium of this tube is seen to terminate by an abruptly de- nned border, illustrating the doctrine held by Mr. Rainey, which contends for the complete absence of all epithelium from all parts of the lung beyond this limit, b marks the sudden manner in which the intercellular passages arise from the extreme bronchi. 203 within the substance of the lungs bear glands like t
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. A section of a minutely injected piece of human lung. (After Rainey.) The section cuts longitudinally a branching bronchial tube. At a, the ciliated epithelium of this tube is seen to terminate by an abruptly de- nned border, illustrating the doctrine held by Mr. Rainey, which contends for the complete absence of all epithelium from all parts of the lung beyond this limit, b marks the sudden manner in which the intercellular passages arise from the extreme bronchi. 203 within the substance of the lungs bear glands like those of the trachea, and, like the latter, they are lined internally by a ciliated cylinder epithelium. This epithelium terminates, by abruptly-defined borders, at the commence- ment of the true pulmonary tissue, (ft) This fact was first shown by Mr. Rainey*: subsequent observers have, however, proved, contrary to the opinion of Mr. Rainey, that the epithelial layer docs not wholly cease at these points (b). It is prolonged over the respiratory segment under the character of •pavement-epithelium. The true bronchi, in every part of the lung, are distinguished by their tubular form and smooth walls (a, /;) — characters in which they contrast with the loculated aspect of the in- tercellular passages. The walls of the minutest bronchi are composed of three coats: a mucous, a mus- cular, and fibrous. Schroeder van der Kolk has proved that unstriped muscular fibres are contained in the parietes of the smallest of these tubes. The illustrations which accom- Fig. DO Sub-mucous tissue from a small bronchial tube in the human lung. (After Hurting.') a, a, a, elastic longitudinal fibres blended with muscular bands; b, b, muscular fascicles disposed circularly; c, c, extremities of the same, showing the absence of tendons. pany the theses of Adrius Adriani are drawn by S. van der Kolk himself, from his own microscopic dissections. In the whale, the structural elements of the wal
Size: 1894px × 1319px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, booksubjectanatomy, booksubjectphysiology, booksubjectzoology
