A treatise on special and general anatomy: in two volumes (Volume 2).

  • Horner, William E. (William Edmonds), 1793-1853.
Date:
1830
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on special and general anatomy: in two volumes (Volume 2). Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    The abdominal cavity varies only, inconsiderably, in its vertical diameter, owing to the resistance of the diaphragm above, and of the pelvis below; neither does it change be- hind, owing to the resistance of the spine, the ribs, and the muscles there. But as the introduction of food, the develop- ment of gazeous substances during digestion, the evolution of the foetus, and many other conditions, require some pro- vision for its undergoing an easy augmentation of volume; the latter occurs principally forwards and laterally, by the yielding of the muscles and by the extension of their apo- neuroses. The diaphragm and the abdominal muscles, for the most part, act alternately; as the former descends in inspiration, the latter relax and give way to the contents of the abdomen: but in expiration, the abdominal muscles contract, and the diaphragm is pushed upwards by the vis- cera. In attempts at the expulsion of faeces, and in par- turition, these muscles contracting and the diaphragm being fixed all at the same moment, the cavity of the abdomen is actually much diminished. The viscera contained in the cavity of the abdomen are of three kinds. One kind is engaged in digestion and as- similation; another in the secretion and excretion of urine; and the third in generation. As these viscera are numerous, and it is of great importance to determine with precision their position and relative situation, anatomists are agreed to divide the cavity of the abdomen into several arbitrary regions. This is the more advantageous, as the bony pro- minences bounding the abdomen are not sufficiently nume- rous and distinct, to afford those points of departure and of relation which they furnish in other sections of the body. To obtain these regions, consider a line or plane as ex- tended across the abdomen, about two inches below the umbilicus, from the superior part of the crista of one ilium as it appears through the skin, to the corresponding point of the other side. Strike on each side a line perpendicu- lar to the preceding by commencing at the lower end of the anterior inferior spinous process of the ilium, and carrying