A cavity, within the spinal cord, which is filled with cerebrospinal fluid. Syringomyelia cavities come in various “shapes and sizes”, from short, spindle-shaped cavities through to long, tense cavities extending throughout the greater part of the spinal cord. Read more cavities that form as a result of spinal injury. The underlying mechanism is partial or complete obstruction of the spinal This clear, water-like fluid forms, for the most part, within the brain, more specifically inside the ventricles of the brain. Blood flows through structures inside the ventricles, called the choroid plexuses, and clear fluid is produced as a result, passing into the ventricle. This process is akin to blood flowing through the kidneys and urine being produced as a result. An important difference is that, unlike urine, the cerebrospinal fluid is not passed out of the body periodically. Instead, the fluid is re-absorbed back into the blood stream, mostly via the arachnoid granulations, into the cerebral venous sinuses. In the course of a 24-hour period, most healthy adults will produce about 500mls (or a pint) of cerebrospinal fluid, although at... channels by scar In everyday speech a piece of tissue is a thin sheet of paper, used to wrap a present or, in a slightly different form, to blow the nose, or to be used in the toilet. In biology the word tissue refers to living material made up of cells or groups of cells of similar type or types. We may speak, for example, of nerve tissue or of fatty tissue, of glandular tissue or of connective tissue. Individual organs of the body, such as the brain, the heart, the liver or the kidneys, are made up of several tissue types, almost always including connective tissue..