from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Alternative spelling of proctodeum.
from the GNU version of the Collaborative International Dictionary of English
- n. See mesenteron.
from The Century Dictionary and Cyclopedia
- n. A posterior section of the alimentary canal or digestive tract, being so much of the whole intestine or enteric tube as is formed at the aboral end by an in growth of the ectoderm: correlated with stomodæum. which is derived from the ectoderm at the oral end—both being distinguished from enteron proper, which is of endodermal origin. Also proctodeum.
- n. The posterior division of the cloaca in such animals as birds, opening externally by the anus: correlated with coprodæum and urodæum.
Sorry, no etymologies found.
An epiblastic tucking-in at st., the stomodaeum pre-figures the mouth; pr., the proctodaeum, is a similar posterior invagination which will become the anus.
The anus is formed by a tucking in, the proctodaeum, similar to the stomodaeum.
The part of the cloaca from the upper wall of which it forms belongs to the proctodaeum, the ectodermic invagination of the rectum (Chapter 2.27); hence its epithelial covering can develop the same horny growths as the corneous layer of the epidermis.