Talk about heterogeneity of smooth muscle cells. (myoepithelial and myoepitheloid)

3- Myoepithelial cells: of epithelial origin, they are smooth muscle cells localized between the basement membrane and glandular cells of acini of some exocrine glands. They are rich in myofilaments and their contraction helps glandular cells expulse their secretion product. 4- Myoepitheloïd cells: They are smooth muscle cells that have undergone a particular differentiation that makes them look like epithelial and secretory cells. Their cytoplasm contains both myofilaments and secretory granules.