The suffix “itis” means inflamed (as in appendicitis). Arachnoiditis therefore means inflammation of the arachnoidA thin, transparent membrane, lying immediately over the brain and spinal cord, and in turn being surrounded by dura. The arachnoid forms thin membranes and strands likened by early anatomists to a spider’s web. Hence its name, referring to spiders, as in “arachnophobia”, which means the fear of spiders. tissueIn 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. surrounding the brain or the spinal cordThe main nerve trunk running down the spinal canal and connecting the individual’s mind and consciousness to the rest of his or her body. It is about the size of a person’s little finger, in diameter. It cannot repair itself if damaged.. Such inflammation can result from infection or from blood “spilt” inside the head or spine, following injury or surgery. The term arachnoiditis is often mis-used to refer to scar tissueIn 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. that forms, within the subarachnoid channelsCerebrospinal fluid forms, for the most part, within the ventricles of the brain. From there it flows out, at the base of the brain, and on over the surface of the brain, then to be re- absorbed back into the bloodstream, mainly into the superior sagittal sinus. Some also flows into the spinal canal. The ventricles and other courses along which the cerebrospinal fluid flows, inside the head and the spinal canal, make up the subarachnoid channels. The term subarachnoid space is commonly used, arguably in error as it implies that these channels are empty, whereas they are, in life, “flooded” with cerebrospinal fluid., as a result of previous arachnoidA thin, transparent membrane, lying immediately over the brain and spinal cord, and in turn being surrounded by dura. The arachnoid forms thin membranes and strands likened by early anatomists to a spider’s web. Hence its name, referring to spiders, as in “arachnophobia”, which means the fear of spiders. inflammation.