The subarachanoid space lies between the arachnoid and pia mater. It is filled with cerebrospinal fluid. All blood vessels entering the brain, as well as cranial nerves pass through this space. The term arachnoid refers to the spider web like appearance of the blood vessels within the space.
Why do biologists organize living things into groups? What do the levels of classification indicate about the relationship between organisms? What characteristics are used to classify organisms into domains and kingdoms? What is the scientific study of how living things are classified called? Taxonomy
Joints permit varying degrees of movements. Joints are classified into three groups: immovable, slightly movable and freely movable. Arthroscopy is the science concerned with the study of joints or articulations.The articulations of the body are classified into three areas:one forming slightly movable joints. The bones forming slightly movable joints are separated by a layer of cartilage or fibrous connective tissues. Eg. The joints formed by adjacent vertebrae contain intervertebral disc formed of cartilage.