Fig. 11. Odontophore-centric model of a seaweed noodle swallow, magnetic resonance imaging (MRI) sequence 7725-S2, frames 44-66. (A-C) Mid-sagittal MR images; (D-F) schematic tracings of the anatomical structures in A-C; (G-L) corresponding odontophore-centric model representations (orthographic projection). (G-I) Latero-medial views; (J-L) dorso-ventral views. The left-hand column is rest (MRI frame 44), the centre column is peak protraction (MRI frame 52) and the right-hand column is peak retraction (MRI frame 63). Note the more tortuous outline of the dorsal I1/I3 muscle (A, solid lines) and the more pronounced shape of peak retraction (C) compared with the 7732-S3/15-38 sequence (see Fig. 9A,C, respectively). The greatly different cross-sectional radii of the six I1/I3 rings are an attempt to capture these anatomical details in the model. As in Fig. 9B, there is also a large apparent stretch of the ventral I1/I3 muscle at peak protraction (B, dotted line) as well as an anterior rotation of the lateral groove plane in vivo that is not duplicated by the model (arrowheads, B and H). The right or left halves of the I1/I3 rings have been cut away in G-L to reveal internal details. e, esophagus; rs, radular stalk. Each frame is 310 ms (real time).