The development of the human body; a manual of human embryology . Fig. 170.—Reconstruction of the Intestine of an Embryo of 19 Figures on the Intestine Indicate the Primary Coils.—(Mall.) secondary coils of the small intestine become more numer-ous and the lower portion of the large intestine is throwninto a loop which extends transversely across the lowerpart of the abdominal cavity and represents the sigmoidflexure of the colon. At the time of birth this portion ofthe large intestine is relatively much longer than in theadult, amounting to nearly half the entire length of thecolon (Tr
The development of the human body; a manual of human embryology . Fig. 170.—Reconstruction of the Intestine of an Embryo of 19 Figures on the Intestine Indicate the Primary Coils.—(Mall.) secondary coils of the small intestine become more numer-ous and the lower portion of the large intestine is throwninto a loop which extends transversely across the lowerpart of the abdominal cavity and represents the sigmoidflexure of the colon. At the time of birth this portion ofthe large intestine is relatively much longer than in theadult, amounting to nearly half the entire length of thecolon (Treves), but after the fourth month after birth areadjustment of the relative lengths of the parts of the27 322 THE DEVELOPMENT OF THE HUMAN BODY. colon occurs, the sigmoid flexure becoming shorter andthe rest of the colon proportionally longer, whereby thecaecum is pushed downward until it lies in the right iliacfossa, the ascending colon being thus Fig. 171.—Representation of the Coilings op the Intestine inthe Adult Condition. The Numbers indicate the PrimaryCoils.—(Mall.) When this condition has been reached, the duodenum,after passing downward for a short distance so as to passdorsally to the transverse colon, bends toward the left andthe secondary coils derived from the second and third THE INTESTINE. 323 primary coils come to occupy the left upper portion of theabdominal cavity. Those from the fourth primary coilpass across the middle line and occupy the right upperpart of the abdomen, those from the fifth cross back againto the left lumbar and iliac regions, and those of the sixthtake possession of the false pelvis and the right iliac region(Fig. 171). Slight variations from this arrangement are not infrequent,but it occurs with sufficient frequency to be regarded as thenormal. A failure in the readjustment of the relative lengths ofthe different parts of the colon may also occasionally occur, inwhich case the caecum w
Size: 1228px × 2035px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectembryol, bookyear1902
