Tooth root. Light micrograph of a horizontal section through a molar tooth. The slit-like root canal (centre) holds the living dental pulp (not seen), which forms the soft central core that carries blood vessels and nerves to and from the tooth. The canals are surrounded by a dumb-bell- shaped layer of hard, mineralised dentine (black and white). Tubules radiating through this layer produce dentine throughout life. Covering the dentine is a thin layer of bone-like material known as cementum. This is attached to the gums and jaw by the periodontal ligament (light yellow), which allows movement when food is chewed. Magnification: x5 at 6x7cm size x2.5 at 35mm size.