The derivation of the Malpighian bodies from the proctodaeum is common to most Tracheata.
If the embryonic mouth and anus do become the adult mouth and anus, there would appear to be an entire absence of stomodaeum and proctodaeum in Peripatus, unless the buccal cavity represents the stomodaeum.
In Crustacea the proctodaeum and stomodaeum, especially the former, are very long, and usually give rise to the greater part of the alimentary tract, while the mesenteron is usually short.
The proctodaeum is surrounded by a great mass of splanchnic mesoblast.
There is, however, a short tube close to the proctodaeum (fig.
The proctodaeum is usually formed in Crustacea before or, at any rate, not later than the stomodaeum[474].
My own impression is that the stomodaeum and proctodaeum have reached their full extension at the present stage, and that both the stomach in the thorax and the intestine in the abdomen are products of the mesenteron.
The stomodaeum has considerably increased in length, and the proctodaeum has become formed as a short, posteriorly directed involution of the epiblast.
In the Tracheata the mesenteron is always considerable, and the proctodaeum is always short.
The mouth and the anus are formed as independent in-pushings, the mouth with stomodaeum first, and the short anal proctodaeum much later.
The yolk-sack of Cymothoa no doubt represents part of the mesenteron, but there is no evidence in favour of any part of the apparent proctodaeum representing it also, though it is quite possible that it may do so.
The proctodaeum is usually formed in Crustacea before and rarely later[216] than the stomodaeum.
The mesoblastic wall of the proctodaeum is probably formed independently of the mesoblastic somites.
The proctodaeumis formed as a shallow pit close to the first formed part of the mesenteron.
A proctodaeum is formed at the hind end of the body slightly later than the stomodaeum.
The proctodaeum continually grows forwards till it approaches close to the stomodaeum, and the two liver sacks, now united into one at their base, become directly continuous with the proctodaeum.
Of the internal changes which take place during the shedding of the cuticle, the first is the formation of a proctodaeum (gh) by an invagination, which ends blindly in contact with the mesenteron.
The proctodaeumgives rise to the abdominal part of the intestine, and the stomodaeum to the oesophagus and stomach.
The proctodaeum is a moderately deep pit near the hinder end of the body.
Before this period the proctodaeum is established as a shallow pit immediately behind the insertion of the foot.
The proctodaeum would appear to be formed later than the stomodaeum, and the earliest stage figured is too far advanced to throw light on the position of the blastopore.
The proctodaeum appears to be formed later than the stomodaeum.
The stomodaeum soon reaches its full length, but the proctodaeum grows forwards above the yolk till it meets the stomodaeum.
The differentiation both of the liver and alimentary tract proper first takes place on the ventral side, and commences close to the point where the proctodaeum ends, and extends forward from this point.
The proctodaeum first appears when the folding off of the tail end of the embryo commences (fig.
The stomodaeum and proctodaeum are formed by epiblastic invaginations.
The proctodaeum gives rise to the bursa Fabricii, as well as to the anus.
Although the opening of the anus is so late in being formed, the proctodaeum itself is very early apparent.
In most forms the original boundary between the epiblast of the proctodaeum and the hypoblast of the primitive cloaca becomes obliterated after the two have become placed in free communication.
The communication between the stomodaeum and the mesenteron is effected comparatively early (on the 4th day in the chick), while that between the proctodaeum and mesenteron does not take place till very late (15th day in the chick).
In some of the Isopods, for example, the stomodaeum and proctodaeum give rise to almost the whole of the alimentary canal with its appendages, except the liver.
Those from the hypoblast are the alimentary tract and its derivates; with which the stomodaeum and proctodaeum and their respective derivates are also dealt with.
Rudiments of the proctodaeumand stomodaeum have appeared, but neither of them as yet communicates with the mesenteron.
In Birds the formation of the proctodaeum is somewhat more complicated than in other types, owing to the outgrowth from it of the bursa Fabricii.
No chitinous lining of the stomodaeum or proctodaeum was found, but it is not certain that any of the sections cut either of those regions.
The proctodaeum can not yet be differentiated from the mesenteron, and only in Cryptolithus has the posterior portion of the alimentary canal been seen.
The proctodaeum or portion of gut leading to anus and formed embryologically by an inversion of the epiblast at that orifice.
Hexapod insects the similar caecal tubes are developed from the proctodaeum or in-pushed portion of the gut which is formed from epiblast.
Later, ulceration takes place in the undermined skin, and the stinking contents of the abscess escape, greatly to the relief of the patient.
The most satisfactory course which it can take is through the wall of the abdomen and out above the right groin.
It occasionally happens that after operation the scar of the wound in the abdominal wall yields under the pressure from within, and a bulging of the intestines beneath the skin occurs.
Such renal caecal tubes seem to be readily evolved from either metenteron or proctodaeum when the conditions of the out-wash of nitrogenous waste-products are changed by the transference from aquatic to terrestrial life.
Renal excretory caeca (Malpighian tubes) are developed from the proctodaeum (not from mesenteron as in scorpion and Amphipoda).
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "proctodaeum" in a variety of sentences. We hope that you will now be able to make sentences using this word.
