Liver lobules form hundreds of irregular plates arranged radially around a central vein (see illustration). There are two types of lobules: (1) the classic hepatic lobule which drains blood from the protein vein and the hepatic artery to the central vein; and (2) the portal lobule which drains bile from hepatocytes to the bile duct.

Tooth enamel covers the crown (topmost portion) of every tooth. Enamel is the human body’s hardest component, consisting of 96% calcium hydroxyapatite and 2-3% organic material. It consists of uniform, interlocking columns called enamel rods (prisms) surrounded by a thinner layer of other enamel. The ameloblasts form the matrix for these enamel rods.

Reference:
Mescher, A. (2018). Junqueira’s basic histology: text and atlas (15th ed.). Mcgraw Hill Education.