noun, plural: cytopharynxes or cytopharynges
The tube-like passageway in certain protozoans through which the ingested food material passes through
The cytopharynx is a tube-like passageway in certain protozoans, such as ciliates and flagellates. It serves as a gullet by which food passes through. It is non-ciliated and of differing lengths depending on the species. It leads from the cytostome, which serves as the mouth. The cytostome is the opening on the cell surface that further leads to an invagination. This invagination is formed by the cytopharynx, which is the tube-like passageway, often directed towards the posterior of the cell. Together with the cytostome, they are referred to as the cytostome-cytopharynx complex (or cytopharyngeal apparatus).
The cytostome-cytopharynx complex functions as follows: the food material (e.g. macromolecule) is taken up and initially has to get through the cytostome. The food is next directed from the cytostome into the cell through the lumen of the cytopharynx. Inside the cell, the food is sealed into the food vacuole where it will be digested through the action of digestive enzymes.
The cytopharynx does not have cilia but they have microtubules that surround it. The part not associated with microtubules is the point at which the food vacuole forms.