Tooth. Coloured light micrograph (LM) of an axial section through an unerupted tooth. At the centre of the tooth is the dental pulp, which contains the nerves and blood vessels of the tooth. The elongated cells on the periphery of the pulp are odontoblasts (pink) that lay down the dentine (thin blue layer), which makes up the bulk of the tooth. The thicker blue layer is enamel, which protects the dentine. Enamel is formed by ameloblasts, a layer of elongated cells around the outside of the enamel.