Final answer:
The enamel is the hardest substance in the body, covering the crown of teeth which are vital for mastication. The crown and root of a tooth have several layers, with enamel on the crown and cementum and dentin in the root, surrounding a pulp cavity with connective tissues, nerves, and blood vessels.
Step-by-step explanation:
The hardest substance in the body is the enamel which covers the crown of the teeth. Teeth are complex structures designed for mastication, and adults normally have a total of 32 teeth with various shapes to assist in chewing different types of food. A tooth consists of two main parts: the crown, which is visible above the gum line, and the root, which is embedded within the jaw bone.
The outermost layer of the crown is enamel, and it is recognized as the hardest material in the body, even harder than bone. Beneath the enamel is a layer of dentin, which is a bone-like tissue that extends into the root of the tooth around the innermost pulp cavity, containing nerves and blood vessels. The root canal is the region of the pulp cavity that runs through the root, and the dentin in the root of the tooth is covered by cementum, another hard bone-like layer. Together, these components of a tooth enable us to efficiently break down food for digestion.