CAVITY. 



507 



regions are proportionally much smaller than 

 in the adult; the epigastric, in consequence of 

 the contracted diameters of the thorax, but more 

 particularly in consequence of the small size of 

 the vault which is formed by the diaphragm ; 

 and the hypogastric by reason of the imper- 

 fectly developed state of the pelvis. Hence, 

 then, we find that most of the viscera extend 

 more or less into the middle or umbilical 

 region, which thus exhibits a very great en- 

 largement. The liver is the viscus which 

 exhibits the most remarkable degree of enlarge- 

 ment; its two lateral lobes present but little 

 difference in size, it extends laterally so as to 

 occupy nearly the whole epigastrium, leaving 

 but a small space at the left side for the 

 stomach and spleen; it passes considerably 

 beyond the inferior margin of the ribs, so that 

 a great portion of it is found in the umbilical 

 region, extending even to the hypogastrium. 

 This great extent of space occupied by the 

 liver necessarily causes corresponding altera- 

 tions in the positions of the neighbouring vis- 

 cera, and of none more than the stomach. The 

 direction of this organ is nearly perpendi- 

 cular, its pyloric extremity is found a little 

 to the right in the umbilical region, while 

 the aspect of its splenic end is upwards and 

 to the left; its great curvature looks to the 

 left side and downwards, and its lesser cur- 

 vature to the right and upwards. The spleen 

 is not altogether contained in the left hy- 

 pochondrium, but also extends into the left 

 lumbar region, and may be felt below the 

 false ribs. The duodenum does not change 

 its positive situation with reference to the 

 spine, but, in consequence of the position of 

 the stomach, its curves are more marked, the 

 superior portion passes more decidedly up- 

 wards, and the whole duodenum is to a greater 

 extent covered by the stomach. The rest of the 

 small intestine is crowded backwards against 

 the spine, and in consequence of the non-deve- 

 lopment of the pelvis is found entirely in the 

 umbilical region ; nor is it covered by the 

 omentum, which as yet has attained but a very 

 small size. At this early period, moreover, the 

 bladder is an abdominal viscus; in general, 

 very capacious and of a cylindrical form, it 

 extends out of the pelvis to within a very short 

 distance of the umbilicus, to which it is con- 

 nected by the urachus, so that it occupies a 

 considerable portion of the hypogastric and a 

 small part of the umbilical regions ; consequently. 

 as Portal remarks, the shortest route by which 

 the bladder can be reached at this early age is 

 according to the method of the suprapubic 

 operation, and it is only a small portion of the 

 neck of the bladder which is at all in relation 

 with the perinaeum. A considerable portion of 

 the rectum, also, is found in the hypogastrium, 

 and in the female the uterus and ovaries and 

 the Fallopian tubes. Prior to the seventh or 

 eighth month of intra-uterine life, when the tes- 

 ticles enter the scrotum, they are found suc- 

 cessively as they descend in different regions of 

 the abdominal cavity, at first in the lumbar 

 regions immediately beneath the kidneys, and 

 then at different heights along the inner side of 



the iliac fossae ; we also observe here that pro- 

 cess of peritoneum connected with the testicle, 

 and extending from it to the inguinal canal, 

 which is known by the name of the diver ticu- 

 lum of Nuck : a similar process exists in a 

 much less developed condition in the female 

 connected with the round ligament. The prin- 

 cipal difference observable, as regards the large 

 intestine in the fetus at its full period, consists 

 in the great curvature of that portion of it that 

 is found iii the left iliac region, occasioned by 

 the narrowness of the pelvis admitting but a 

 small part of the rectum.* In the progressive 

 development which takes place during intra- 

 uterine life, the position of this as well as of the 

 other portions of the intestinal canal presents dif- 

 ferences which it does not belong to the present 

 article to examine. (See INTESTINAL CANAL.) 



The capacity of the abdominal cavity and 

 the position of some of its contained organs, 

 as they thus exist in the fetus at its full period, 

 continue pretty nearly the same for some time 

 after birth. The enlargement, however, of the 

 vault of the diaphragm increases the capacity 

 of the epigastrium, while the gradual diminu- 

 tion of the liver affords room for the passage 

 of more organs from the umbilical region up- 

 wards, and the stomach is allowed to take a 

 more horizontal direction. These changes, 

 which are gradual in the periods of life prior 

 to puberty, become most manifest when the 

 arrival of that period gives rise to the enlarge- 

 ment of the pelvis ; then the umbilical region 

 is as it were relieved from its overloaded state ; 

 the belly is less prominent, for the bladder 

 now occupies its proper place in the pelvic 

 cavity; the rectum, too, sinks into it, and many 

 of the convolutions of the small intestine are 

 found in it: thus, by the enlargement of the 

 hypochondria in the first instance, and subse- 

 quently by the development of the pelvis, the 

 three subdivisions of the abdominal cavity 

 assume those proportions in their respective 

 magnitudes which are characteristic of the 

 adult period. 



In considering the probable amount of in- 

 jury inflicted by wounds which may have pene- 

 trated the abdominal cavity, we must take into 

 account the changes which the different atti- 

 tudes of the body occasion in the positions of 

 the viscera. These changes cannot be exten- 

 sive, and only regard the position of each 

 viscus with reference to the whole cavity, the 

 relations of that viscus to the neighbouring 

 ones being unaltered, or nearly so. They take 

 place in obedience to the law of gravitation, 

 and it is so easy, by a little reflection, to de- 

 duce what the changes must be, keeping in 

 mind the various means made use of to limit 

 and prevent displacement, that it seems unne- 

 cessary to do more here than allude to the fact 

 that the viscera are altered in position under 

 the influence of such a cause. 



ABNORMAL CONDITIONS OF THE ABDOMI- 

 NAL CAVITY. All the abnormal conditions of 



* See on this subject Portal, Anat. Med. torn. v. 

 Blandin, Anat. Topog. and Meckel, Anat. Gen. 

 Dcsc. et Path. torn. iii. 



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