PhaFIG 4E-I: The anterior digestive track is formed by the alignment of a series of cells.

E&F. The thin ring of the syncytial hyp 1 cell surrounds the anterior buccal cavity in an adult (see Epithelial System - Hypodermis).
E. Epifluorescent image of hyp 1 in an animal expressing a GFP-tagged transgene. Inset shows hyp1 in a larval animal from the same strain. (Strain source: Z-W. Wang and B. Chen.) Original magnification, 400x.
F. Same animal in merged DIC and epifluorescent images.
G. Two consecutive rings of arcade cells, anterior and posterior, lie just behind hyp1 and anterior to pharyngeal epithelium along the buccal cavity. Epifluorescent images taken from an animal expressing a GFP-tagged transgene. (Strain source: Z-W. Wang and B. Chen.) Magnification, 600x.
H. Same image as in G, magnified.
I. Graphic rendition of the structure of the anterior alimentary canal. The processes of hyp1 and arcade cells extend along the pharynx to reach the buccal region. Pharyngeal tissues (pharyngeal epithelium and pharyngeal muscles) begin posterior to the arcade rings.

See also PhaFIG 4A-D

Click on picture for full resolution image.