In neck extension, the dura mater of the cervical spine is slack and thrown into transverse fold
. In neck flexion, the dura becomes tighter because the length of the cervical canal increases as the neck moves from extension to flexion.
Distally the dorsal diverticula are confined by a transverse fold overlying the medial diverticula and running between the hooked branches of the two lateral apodemes (Figs.
However, in several other species where the specimens are prepared, a sort of transverse fold can be observed in the same area, as if a narrow part of the anterior of the carapace is wrapped over the posterior.
togoensis have a transverse fold on the carapace, which is lacking in C.
The inside surface of the packaging wrapper lies on the liquid-impermeable surface of the body and is folded along one transverse fold
line through the body to form a package.
In pirarucu, circular and transverse folds
are predominant throughout the mid-gut and pyloric caeca and most likely contribute to slow the passage of the chime through the intestine, thereby prolonging its intestinal permanence for the digestion and nutrient absorption processes.
Double-contrast barium studies may occasionally reveal fixed transverse folds in the distal esophagus, with trapping of barium between the folds, producing a characteristic stepladder appearance (Figure 19).
Fixed transverse folds in the esophagus: A sign of reflux esophagitis.
However, the undifferentiated budding zone of Mytilus is followed by a 'transition zone' characterized by a number of transverse folds that have not yet split medially into the lobules of the two demibranchs (as in Unio.
In Nucula, both the transverse folds and the separation of inner and outer demibranchs occur simultaneously.
In each example, the transverse folds form in a way similar to that of protobranchs and filibranchs: the folds split into inner and outer demibranchs.
(11) Fixed transverse folds
may develop in the region of a stricture as a result of longitudinal scarring from reflux esophagitis.