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 eighth and final image in the series.
Earlier images start at the leftmost edge of the pharynx and 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 Motor Neuron M1
Description: M1 is a pharyngeal motor neuron of unknown function. Its cell body is in the right subdorsal anterior terminal bulb. It has a single long process that extends anteriorly through dorsal isthmus and corpus to the anterior tip of the procorpus, where it synapses on pm1, pm2, and pm3 muscles. It is the only neuron with morphologically obvious synapses on those muscles. (See Pharynx section; Albertson and Thomson, 1975; M1 neuron page.)
Pharynx Focal Plane 8
Identification: M1 is a medium-size neuronal nucleus in the right subdorsal anterior terminal bulb. It is just dorsal and posterior to pm5R, a big fried egg, and is straight anterior of g1P, another fried egg in posterior dorsal terminal bulb. pm5R, M1, g1P, and mc2DR (another fried egg just ventral of d1D, and straight posterior of pm5R) form an easily recognized trapezoid.