An interactive Flash diagram of the layers of tissue that protect the human brain, known as the meninges. These layers are divided into the Dura mater, the Arachnoid membrane (named for its spider web appearance), and the Pia mater. Cerebrospinal fluid flows through a ‘subarachnoid’ space between the arachnoid and pia layers. Zoom in, highlight, or label individual sections of the diagram.