Gastrointestinal: Adjective referring collectively to the stomach and small and large intestines. The commonly used abbreviation for gastrointestinal is GI. (Outside of medicine, GI can also stand for galvanized iron, general issue or government issue-as in GI Joe).
Before the extracellular matrix is calcified, the tissue is called osteoid (bone-like) tissue. When the concentrations of calcium and phosphate ions rise high enough, they are deposited into the extracellular matrix, and the bone calcifies.
Osteology is one of the most delightful branches of comparative anatomy, and one not very hard to master. comparative anatomy, physiology, and ontogeny are of the first importance. His object was a comparative anatomy of the two masquerades, and the parallelism was melancholy. You must have comparative theology as you have comparative anatomy.