In this article we will discuss about the anatomy of sycon.
L.S. of Sycon:
Fig. 93. L.S SYCON
1. Body wall is diploblastic with an outer ectodermal or dermal epithelial layer and inner gastric epithelial layer or endoderm.
2. Non-cellular mesenchyme layer with interspersed monaxon and triaxon spicules is present in between the two layers.
3. The dermal epithelium is made by flat pinacocytes and is perforated by ostia.
4. The ostia lead into incurrent canals which through prosopyles lead into radial canals which are lined with choanocytes.
5. The radial canals lead into small ex-current canals which are lined by pinacocytes.
6. The ex-current canals open into spongocoele.
7. The canal system is of syconoid type.
T.S of Sycon:
1. Body wall is diploblastic with an outer dermal layer and inner gastric layer.
2. The gastric layer is made up of mesenchym with interspersed monaxcr and triaxon spicules and is lined internally with flat pinacocyte cells.
3. The dermal layer is also made by flat pinacocytes and is perforated by ostia.
4. The ostia leads into incurrent canals which, through prosopyles, lead into radial canals which are lined with choanocytes.
5. The radial canals lead into small ex-current canals and are lined by pinacocytes.
6. The ex-current canals open into spongocoel.
7. The canal system is of syconoid type.