Archive image from page 1283 of Cunningham's Text-book of anatomy (1914). Cunningham's Text-book of anatomy cunninghamstextb00cunn Year: 1914 ( 1250 THE DIGESTIVE SYSTEM. the abdomen. Already, at the fifth or sixth week, the adult form of the stomach is clearly indicated. This rotation of the stomach around its long axis, which is accompanied by a rotation of the lower end of the oesophagus, explains the asymmetrical position of the two vagi. In the adult the left nerve is found on the front of the stomach, which was originally the left side of the organ; similarly, the right nerve lies on th
Archive image from page 1283 of Cunningham's Text-book of anatomy (1914). Cunningham's Text-book of anatomy cunninghamstextb00cunn Year: 1914 ( 1250 THE DIGESTIVE SYSTEM. the abdomen. Already, at the fifth or sixth week, the adult form of the stomach is clearly indicated. This rotation of the stomach around its long axis, which is accompanied by a rotation of the lower end of the oesophagus, explains the asymmetrical position of the two vagi. In the adult the left nerve is found on the front of the stomach, which was originally the left side of the organ; similarly, the right nerve lies on the back, which was originally the right side. Intestines.—At first there is no separation into large and small intestines; the primitive canal simply forms a slender tube, with a convexity towards the umbilical orifice, through which the vitelline duct passes to the yolk sac. Later, the tube increases in length, and in embryos of 11 or 12 mm. an outgrowth of the canal appears, which represents the future caecum, and indicates the separation into large and small intestines. Growing longer, the intestine forms a large loop with the vitelline duct springing from its apex (Fig. 973), and the superior mesenteric artery running down between the layers of its mesentery. At the same time the two extremities of the coil approach one another, and form a narrow neck to the loop, as shown in Fig. 973. There now takes place a change which entirely modifies the position of the parts—this is a rotation of the whole loop, with its mesentery, around the superior mesenteric artery as an axis (Fig. 973). The result of this rotation is that the original right side of the loop of gut and mesentery becomes the left side; and the beginning of the large intestine is carried across the duodenum (Fig. 973), thus explaining the passage of the transverse colon in front of the second part of the duodenum in the adult. At the same time the caecum comes to lie near the middle of the abdomen below the live
Size: 1535px × 1303px
Photo credit: © Bookive / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: 1910, 1914, anatomy, archive, book, bookauthor, bookdecade, bookpublisher, booksubject, bookyear, cunningham_d_j_daniel_john_1850_1909, drawing, historical, history, illustration, image, new_york_w_wood, page, picture, print, reference, robinson_arthur_b_1862_ed, vintage
