Pharynx Atlas Home

The pictures that comprise the Pharynx Atlas are a focal series through the terminal bulb of the pharynx. The worm is lying on its right side, with anterior towards the upper left and posterior towards the lower right. Dorsal is the upper right and ventral is the lower left.
This is the second image in the series. Subsequent images go consecutively deeper, until the last goes through the very rightmost edge. The focal planes are not equally spaced. They were chosen so that all the nuclei in the terminal bulb would be clearly visible in at least one image.

Click on individual pharyngeal cells to identify them.

Pharyngeal Gland Cell g1AL

Description: The three g1 nuclei belong to two gland cells that fill the most anterior and most posterior regions of the terminal bulb. g1P and g1AR belong to the same cell. These cells extend three processes anteriorly in dorsal and subventral locations. The two subventral processes end just posterior to the metacorpus. The dorsal process extends almost to the buccal cavity. All three processes are exposed to the pharyngeal lumen at their tips.

The gland cells are active at molting. Refractile granules are formed and transported anteriorly through the processes to the tips, where they appear to be secreted into the pharyngeal lumen. However, in one rather sloppy experiment killing them had no obvious effect on molting or anything else (L. Avery, unpublished). Perhaps they secrete a coating that covers the cuticle; such coatings are known in some parasitic species. (See Pharynx section; Albertson and Thomson, 1975.)

Pharynx Focal Plane 2

Identification: All three g1 nuclei are large fried eggs. Together with the lateral and dorsal pm5 nuclei they form a triangular cluster in the subdorsal anterior terminal bulb, dorsal to the pm5V nuclei. Each g1A is anterior ventral of a neuron (M1 on the right, I6 on the left). g1P is in right posterior subdorsal terminal bulb, just dorsal to mc2DR. pm5R, M1, g1P, and mc2DR form an easily recognized trapezoid.