86 



ing of the weight of the food, as one of the causes which enable it to pass 

 along the oesophagus*. Although, in man as in quadrupeds, that weight 

 is no object to deglutition, it favours that function in so slight a degree, 

 that the diminution of muscular contractility at the approach of death, 

 is sufficient altogether to prevent it. The act of drinking is then attend- 

 ed with a noise of 'unfavourable omen. This noise consists in a gurgling 

 of the fluid which has a tendency to get into the larynx, whose opening 

 is not covered ever by the epiglottis; and if it be insisted upon, that the 

 patient shall swallow some pitsan, tfce deglutition of which is impractic- 

 able, it flows into the trachea, and the patient dies of suffocation. 



XIII. Of the Jlbdoimn\. Before inquiring any farther into the pheno- 

 mena of digestion, let us shortly attend to the cavity which contains its 

 principal organs. The abdomen is almost entirely filled by the digestive 

 apparatus, of which the urinary passages form a part: its size, the struc- 

 ture of its parietes, are evidently adapted to the functions of that appara- 

 tus. The capacity of the abdomen, exceeds that of the other two great 

 cavities; its dimensions are not invariably fixed, as those of the skull, 

 whose size is determined by the extent of its osseous and inelastic pari- 

 etes. They are likewise more varying than those of the chest, because 

 the degree of dilatation, of which the latter is susceptible, is limited by 

 the extent of motion, of which the ribs and sternum are capable. The 

 abdomen, on the contrary, enlarges in a sort of indefinite mariner, by the 

 yielding of its soft and extensible parietes. In some cases of ascites, the 

 abdomen has been known to contain as much as eighty pints of liquid, 

 and yet death has not followed as a consequence of so enormous an accu- 

 mulation; while in consequence of the delicate texture of the brain, of 

 the exact fulness of the skull, and especially of the inflexibility of its pa- 

 rietes, the slightest effusions within that cavity are attended with so much 

 danger; while the collection of a few pints of fluid, within the chest, oc- 

 casions suffocation. This vast capacity of the abdomen, capable of being 

 easily increased, was required in a cavity whose viscera, for the most part 

 hollow, and admitting of dilatation, contain substances varying in quanti- 

 ty, and from which are disengaged gases occupying a considerable 

 space. What a difference is there not, in the capacity of the abdomen 

 of animals, according to the quality of the food on which they feed] 



* A very curious instance of deglutition may be seen in the Java bat ; vespertilio vam- 

 pi/rns, ofLinnsus. The specimen of this animal, lately living- in the Philadelphia Mu- 

 seum, was continually pendent, by the hooks of one or both leg's. In this situation it 

 took food, which, when masticated, was forced, by a peculiar muscular movement, to 

 ascend perpendicularly to the stomach. Godman. 



}- It is requisite, in physiology, as well as in medical practice, to have an artificial di- 

 vision of the abdominal cavity, in order to point out the exact and relative situations of 

 the viscera which it contains. With this view, it has been usually divided into three 

 regions, called the upper, middle, and under region : each of these is subdivided into three 

 others. The UPPKH region begins at the ensiform cartilage, and extends downwards to 

 about four inches from the umbilicus ; the middle of it is termed the epigastrium^ and 

 the t\vo lateral portions hypochondria, from their situation under the cartilages, of the. 

 false ribs. 



The MIDDLE region occupies about four inches above and below the umbilicus. Its 

 middle portion is called the umbilieul, uncl its lateral parts the loins or lumbar regions. 

 The TI.VDER division of the abdominal cavity commences where the former one termi- 

 nates, or at a line drawn between the superior and anterior spinous process of the ossa 

 ilii, and forms, in the middle, the hupogaatrium, or bottom of the belly ; and at the sides, 

 the iliac regions. Copland. 



