The human parotid gland (PG) is developed from an ectodermal proliferation of the
stomodeum during the sixth week of prenatal development (Moore & Persaud, 2002).
Other visible structures are the
stomodeum and the labrum, located in the central portion of the naupliar embryo.
During the larval stages, at the junction of the
stomodeum with mesodeum, two pairs of caeca are present--an anterior pair formed by a simple tubule and a lateral pair with three lobes (Fig.
Neuroendocrine tumors would not be expected to occur in tissue derived from the primitive
stomodeum.
Taxonomic value of the cuticular structures of the
stomodeum in Acridomorpha.
These beetles have a typical digestive system divided into three regions:
stomodeum, mesenteron and proctodeum.
The adenohypophysis, or anterior pituitary, is derived from an evagination of oral ectoderm of the dorsal median region of the
stomodeum. The neurohypophysis, or posterior pituitary, is derived from an evagination of the infundibular portion of the diencephalon of the brain.
Ctenophores display features of bilateral symmetry around the oral-aboral axis: the flattened
stomodeum defines the sagittal plane, and an orthogonal tentacular plane passes through the two tentacle pouches.
The
stomodeum appeared at stage 13 and the prototrochal girdle with its cilia were completely formed during stage 14 (Fig.