The C. elegans grinder is a specialization of the C. elegans pharyngeal cuticle, located in the medial part of the terminal bulb.

(A i) A cartoon representative of a day-1 adult animal. (A ii) Magnified view of boxed region in (i). Pharynx muscle cells, denoted in crimson, synthesize and secrete the extracellular matrix components that form the pharyngeal cuticle, denoted in black, which lines the alimentary tract from the procorpus through the terminal bulb. The pharyngeal-intestinal valve (VPI) cells are shaded in green and are denoted with an arrow. (B) A 3D cartoon of a day 1 adult animal, with a blue rectangle depicting the approximate angle at which each specimen was cut longitudinally (the cutting plane). The animal is facing the viewer at a 45º angle and the pharynx is shown in the head/neck region in crimson. Scale bars = 10 μm.

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