Volume 2

The anatomy and physiology of the human body.

  • Bell, John, 1763-1820.
Date:
1826
Catalogue details

Licence: Public Domain Mark

Credit: The anatomy and physiology of the human body. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    58/664 (page 38)
    (ad). When the diaphragm contracts and descends, it can not uniformly descend as represented in the lateral plan ; for we have understood that it is tied up by the mediastinum. The perpendicular dark line represents the mediastinum. Thus the arch (aa) instead of descending in a single arch, acts on its lateral parts principally, and assumes the form (bb). As it was formerly explained, it acts on the lungs more than on the heart and vessels. The student who has attended to the anatomy and relations of the lungs, must perceive that the rising and falling of the chest, and the propulsion upwards of the diaphragm (by the abdominal muscles,) and its descent, must influence the lungs, alternately draw- ing the atmospheric air into them and expelling it; and thus the act of respiration is performed, the lungs being passive. He must perceive that by this mechanism, in which the whole muscles of the neck, chest, and abdomen, and back are concerned, there