Prenatal development of the human parotid gland

ABSTRACT

The prenatal development of the human parotid gland has been investigated in 26 fetuses from the 10th week of gestation to full term. At 10-12 weeks, the gland was composed of primitive ducts and terminal buds of primitive acini surrounded by loose mesenchyme. The acini continued to increase in number and size till full term. At 16 weeks, the lobulation of the developing gland was recognizable together with differentiation of the primitive ducts into intra- and interlobular ducts. At 20 weeks, both intercalated and striated ducts were distinguished and their number increased gradually with age. At birth, the ducts and acini appeared fewer and less crowded than those of the adult and the gland appeared devoid of fat cells. PAS- and AB-positive secretory materials appeared in the epithelial cells of both ducts and acini and in their lumina during the 12th week. This secretory activity persisted throughout pregnancy. The functional significance of the secretory products is discussed