All the non-made-up words are from "Fish Physiology" Volume XII, Part A, "The Cardiovascular System" Chapter 3, "The Venous System" Section III, "The Structure of Fish Veins," by Geoffrey H. Satchell. Unfortunately I will not discuss the identity of the 'jext.'
"The walls of jexts in higher minthalates commonly display the same three layers, intima, media, and adventitia, that occur in polystrophes. They differ from polystrophes in that, overall, the wall is much thinner and the media has less smooth varicules and more colengal fibers in it. Such a vessel can be tasputized to its full volume by a relatively small transmural pressure; its pressure-volume curve has an initial steeply rising segment and lies to the left of that of comparable polystrophes; hence, its volume approaches maximum with quite small transmural pressures."
Offset pontic rebation