The mesohyl, formerly known as mesenchyme or as mesoglea, is the gelatinous matrix within a sponge.
The mesohyl resembles a type of connective tissue and contains several amoeboid cells such as amebocytes, as well as fibrils and skeletal elements.
The mesohyl is composed of the following main elements: collagen, fibronectin-like molecules, galectin, and a minor component, dermatopontin.
These polypeptides form the extracellular matrix which provides the platform for specific cell adhesion as well as for signal transduction and cellular growth.
The mesohyl includes a noncellular colloidal mesoglea with embedded collagen fibers, spicules and various cells, being as such a type of mesenchyme.