Anatomical Discrimination of the Differences Between Torn Mesentery Tissue and Internal Organ-surface Primo-vessels

(A) Sample of a primo-vessel on the surface of the small intestine after incision and exposure of the abdominal cavity. (B) Magnified view of the rectangular area highlighted in Figure 1A (the primo-vessel is visibly held by forceps). (C) A primo-node inside the folds of the colon, found by following the primo-vessel on the surface of the small intestine. (D) A primo-vessel on the surface of the small intestine and branches to the large intestine.

(A) Mesentery under tension from forceps (arrows). The mesentery appears similar to a primovessel, but is connected tightly to the internal organ. The transparent membrane is connected within the dashed triangle. (B) Tearing of mesenteric tissue causes it to appear similar to a primo-vessel, but it is strong enough to withstand tension. (C) The membrane structure (outlined in the dashed triangle) remains at the end of the torn mesentery (arrows). Unlike a primo-vessel, torn mesentery does not branch or reach a primo-node, but connects to the mesentery.

(A) Primo-vessel observed by optical microscopy. Bundle patterns are clearly observable (arrows, 100×). (B) Higher magnification of Figure 3A (400×; scale bar, 50 μm).

(A) Torn mesentery by optical microscopy. At low (100×) magnification, the elongated structure of torn mesentery resembles a primo-vessel. (B) A higher magnification of Figure 4A. Irregular patterns are seen in place of the bundle structure of the primo-vessel tissue (400×; scale bar, 50 μm).