Vol. 10, Special Issue 10 (2021)

Author(s):
Arti Singh, MM Farooqui, Abhinov Verma and Renu Yadav

Abstract:
The primordium of the tongue was noticed at 38 days of gestation and consisted of two distinct lateral swellings covered by epithelium. Below the epithelium mesenchymal cells contains differentiating myocytes, differentiating leucocytes and numerous blood vessels were present. The epithelium was two layered at 38 days of gestation. The epithelium on the ventral surface was single layered at 38 days of gestation. The discontinuous basement membrane was observed first time at 43 days of gestation. The blastemic tissue was composed of differentiating mesenchymal cells, differentiating fibroblasts, R.B.Cs and differentiating lymphocytes. The differentiating myocytes were noticed first time among the mesenchymal cells at 38 days of gestation and their long axis were oriented either parallel or perpendicular to surface epithelium. Elongated or spindle shaped nucleus with evenly distributed chromatin material was placed centrally within the fibers. Between 43 to 46 days of gestation skeletal muscle fibers were arranged in three different directions (longitudinal, transverse and oblique). Histochemical studies revealed that the basal and superficial layers of epithelium, propria submucosa, and lingual intrinsic muscle showed mild to moderate reaction for PAS and bound lipid in early gestation but could not show any reaction for AMP.