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).
Barium sulfate (or sulphate) is the inorganic compound with the chemical formula BaSO 4. It is a white crystalline solid that is odorless and insoluble in water. It occurs as the mineral barite, which is the main commercial source of barium and materials prepared from it.lthough barium is a heavy metal, and its water-soluble compounds are often highly toxic, the low solubility of barium sulfate protects the patient from absorbing harmful amounts of the metal. Barium sulfate is also readily removed from the body, unlike Thorotrast, which it replaced.