The anatomy of the human lung / by A.T. Houghton Waters.

  • Waters, A. T. H. (Alderman Thomas Houghton), 1826-1912.
Date:
1860
Catalogue details

Licence: Public Domain Mark

Credit: The anatomy of the human lung / by A.T. Houghton Waters. Source: Wellcome Collection.

    86/270 (page 70)
    Arrangement of the Cartilages. — There is no con- stant, uniform manner in which the cartilages are arranged. They are not of equal depth nor thick- ness, nor are they all placed parallel to each other. They occasionally bifurcate behind, and sometimes two or even three are partially united. Again, at times a cartilage extends only half round the tube, and may remain independent of those between which it is placed, or may unite with one of them. There are some peculiarities in the arrangement of the first and last cartilages. The first is broader than the others, especially in the median line, and is often connected with the cricoid cartilage. The last carti- lage, placed at the bifurcation of the trachea, has its lower border prolonged downwards in the median line, and at the same time backwards, so as to form a spur-shaped projection between the two bronchi; from this process two semicircular cartilages are derived, each of which goes to form the commence- ment of a bronchus. The last cartilage but one presents in the median line a projection downwards, and sometimes back- wards, similar to that of the last, but to a much less extent; and occasionally the last cartilage but two has a slight projection downwards. The posterior border of the cartilages usually pro- jects farther back on the right side than on the left; this results from the position of the esophagus. Each cartilage is inclosed in a fibrous sheath, previously described. The first cartilage is attached to the cricoid cartilage by means of the fibrous tube wh.ich descends from the lower border of the latter,