Echinodermata, Hemichordata and Xenoturbellida form the clade Ambulacraria. The present phylum Priapulida also has a deuterostomic development, despite being otherwise placed within the protostomes. In both deuterostomes and protostomes, a zygote first develops into a hollow ball of cells, called a blastula.In deuterostomes, the early divisions occur parallel or perpendicular to the polar axis. This is called radial cleavage, and also occurs in certain protostomes, such as the lophophorates.chinodermata, Hemichordata and Xenoturbellida form the clade Ambulacraria. The present phylum Priapulida also has a deuterostomic development, despite being otherwise placed within the protostomes. In both deuterostomes and protostomes, a zygote first develops into a hollow ball of cells, called a blastula.
In this test you drink some barium liquid. The barium liquid is often fruit-flavoured so it is pleasant to drink. You stand in front of an X-ray machine whilst X-ray pictures are taken as you swallow. This test aims to look for problems in the gullet (oesophagus).
In the X-ray room you will be told when and how fast to drink the barium solution, usually about one cup in total. If X-rays are to be taken of your stomach (a barium meal test), you may also be asked to drink a small amount of one or 2 other liquids.These liquids combine to produce a gas that expands your stomach, making it easier to detect any abnormalities in its lining.f X-rays are to be taken of your stomach (a barium meal test), you may also be asked to drink a small amount of one or 2 other liquids. These liquids combine to produce a gas that expands your stomach, making it easier to detect any abnormalities in its lining.