stomodeum


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stomodeum

 [sto″mo-de´um]
the ectodermal depression at the head end of the embryo, which becomes the front part of the mouth.

sto·mo·de·um

(stō'mō-dē'ŭm),
1. A midline ectodermal depression ventral to the embryonic brain and surrounded by the mandibular arch; when the buccopharyngeal membrane disappears, it becomes continuous with the foregut and forms the mouth. Synonym(s): stomatodeum
2. The anterior portion of the insect alimentary canal, consisting of mouth, buccal cavity, pharynx, esophagus, crop (frequently a diverticulum), and the proventriculus.
[Mod. L. fr. G. stoma, mouth, + hodaios, on the way, fr. hodos, a way]

stomodeum

/sto·mo·de·um/ (sto″mo-de´um) an invagination of the surface ectoderm of the embryo, at the point where later the mouth is formed.stomode´al

stomodeum

also

stomodaeum

(stō′mə-dē′əm)
n. pl. stomo·dea also stomo·daea (-dē′ə)
The anterior or oral portion of the digestive tract of an embryo.

sto′mo·de′al (-dē′əl) adj.

stomodeum

[stom′ədē′əm] pl. stomodeums, stomodea
Etymology: Gk, stoma + odaios, a way
a depression in the ectoderm located in the foregut of the developing embryo that forms the mouth. Also spelled stomadaeum, stomadeum, stomodaeum. Compare proctodeum. stomadeal, stomodaeal, stomodeal, adj.

sto·mo·de·um

, stomatodeum (stō'mō-dē'ŭm, -mă-tō-dēŭm)
1. A midline ectodermal depression ventral to the embryonic brain and surrounded by the mandibular arch; when the buccopharyngeal membrane disappears, the stomodeum becomes continuous with the foregut and forms the mouth.
2. The anterior portion of the insect alimentary canal.
[Mod. L. fr. G. stoma, mouth, + hodaios, on the way, fr. hodos, a way]

sto·mo·de·um

, stomatodeum (stō'mō-dē'ŭm, -mă-tō-dēŭm)
A midline ectodermal depression ventral to the embryonic brain and surrounded by the mandibular arch; when the buccopharyngeal membrane disappears, the stomodeum becomes continuous with the foregut and forms the mouth.
[Mod. L. fr. G. stoma, mouth, + hodaios, on the way, fr. hodos, a way]

stomodeum (sto″mode´əm),

n a superficial depression on the ectoderm of the developing embryo that later becomes the oral cavity; primitive mouth.

stomodeum, stomodaeum, stomatodaeum, stomatodeum

the ectodermal depression at the head end of the embryo, which becomes the front part of the mouth.
References in periodicals archive ?
The juvenile buccal organ also forms ventral to the larval stomodeum (Fig.
The stomodeum does not appear to be derived from either the blastopore or the area in which the blastopore forms.
Fully grown bipinnariae had ciliary bands divided into two loops; five conspicuous pairs of bipinnarian arms, which are hollow extensions of the body wall with ciliary bands arranged along the edge; and a complete gut formed by the fusion of the stomodeum to the anterior tip of the archenteron.
In this type, the stomodeum fused to the anterior tip of the archenteron and then the archenteron differentiated into intestine, stomach, and esophagus.
On the other hand, in types 1 and 2 larvae, the stomodeum formed at the anterior ventral region within a day of insemination.
One band forms in the lateral stomodeal region, while a second passes immediately posterior to the stomodeum.
hexactis have a digestive tract consisting of a stomodeum, esophagus, and stomach.
squamulosa would be expected next as it has a stomodeum and vestiges of the ciliated band.
The stomodeum itself has three dorsal diverticulae and opens to the stomach through a pharyngeal valve in the midposterior floor of the stomodeal cavity (Fig.
Mesoderm-lined coelomic compartments are visible anterior to the stomodeum and along the ventral midgut and hindgut (Fig.
The transient appearance of a larval stomodeum and anus, described for Asterina gibbosa (MacBride, 1896; Marthy, 1980), was not observed in P.