A solution that produces ions (an ion is an atom or group of atoms that conduct electricty.  In medical usage electrolyte usually means the ion itself; thus the term serum electrolyte level means the concentration of separate ions (sodium, potassium, choride, bicarbonate, etc) in the circulating blood.

A variety of white blood cell distinguished by the presence in its cytoplasm of coarse granules that stain orange-red with Romanowsky stains.  The function of the eosinophil is poorly understood, but it is capable of ingesting foreign particles, is present in large numbers in lining or covering surfaces within the body, and is involved in allergic responses.

The extremely thin membrane, composed of cells of the glia (ependymal cells), that lines the ventricles of the brain and the choroid plexuses.  It is responsible for helping to form cerebrospinal fluid.

A cerebral tumour derived from the glial (non-nervous) cells lining the cavities of the ventricles of the brain.

A malignant tumour of bone occurring in children and young adults.  Distinguished from osteosarcoma by J.Ewing in 1921, it commonly arises in the femur but is liable to spread to other bones and to the lung.  It usually presents with pain, often associated with fever and leucocytosis.