This Article  • Full text  • PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Contact me when this article is cited  Related Content  • Similar articles in this journal

	Since this article does not have an abstract, we have provided the first 150 words of the full text and any section headings.

As you know, embryology is a speculative science. This is the reason why the words "probably," "perhaps," and "most likely" appear often in texts. In the "Surgical Anatomy" section in a recent issue of the ARCHIVES (2000;135:314), the sentence "The distal third of the transverse colon to the anus arises from the hindgut" is not embryologically and anatomically correct.

The anal canal, with an approximate length of 4 cm, is perhaps a product of the cloaca.¹ Anatomically, it is subdivided by the pectinate line (or close to the pectinate line) into 2 parts: the upper (proximal) 2 cm from the pelvic diaphragm to the pectinate line, and the lower (distal) 2 cm from the pectinate line to the anal verge. The hindgut is most likely responsible for the genesis of the upper 2 cm. Embryologically, the lower 2 cm is of ectodermal origin.

Table 1² summarizes the differences above and . . . [Full Text of this Article]