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.
An osteoid osteoma is a benign bone tumor that arises from osteoblasts and was originally thought to be a smaller version of an osteoblastoma. Osteoid osteomas tend to be less than 1.5 cm in size. The tumor can be in any bone in the body but are most common in long bones, such as the femur and tibia.