PhaFIG 6A-C: Muscle cells of the pharynx.

A. There are eight muscle segments (pm1-pm8) in the pharynx. All but pm6, pm7 and pm8 form syncytia. The most anterior segment, pm1, is a single cell with six nuclei. Its processes extend anteriorly adjacent to the anterior edges of the marginal cells and terminate in a ring structure. Each pm2 soma has two nuclei and projects into a nerve ring to extend anteriorly. pm3 cells are located in the procorpus, pm4 in the anterior bulb, and pm5 in the isthmus. pm4 and pm5 are single syncytia forming bridges (asterisk) between each trilateral sector Harry et al (2022) (see PhaFIG 7A). The terminal bulb contains pm6-pm8. The last muscle segment contains a single cell, pm8, that has a single nucleus located on the left side.
(Top insets) Epifluorescence images of pm1 (left), pm6 (middle), and pm8 (right) in animals expressing GFP-tagged transgenes. (Strain source: Z-W. Wang and B. Chen.) Each magnification, 400x. 
B. Pharyngeal muscle cells contain radially oriented filaments. Here, myofilaments in pm3-pm7 can be seen in an epifluorescence image taken from a transgenic animal expressing the reporter gene, C32F10.8::GFP. (Asterisk) Position of g1 gland cells. (Image source: R. Newbury.) 
C. Muscles of the terminal bulb. Epifluorescence image from a transgenic animal expressing the reporter gene, K02A4.1::GFP. (Image source: R. Newbury.)
Pharynx 3D is an interactive viewer that allows the user to explore the anatomy of the pharynx in detail by manipulating the pharyngeal structures in three dimensions. Menu options allow for toggling between different views.age from a transgenic animal expressing the reporter gene, K02A4.1::GFP. (Image source: R. Newbury.)

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