Singh Amandeep, Kaur Simran, Singh Opinder
Department of Veterinary Anatomy, Lala Lajpat Rai University of Veterinary and Animal Sciences (LUVAS), Hisar, Haryana, India.
Department of Animal Genetics and Breeding, Lala Lajpat Rai University of Veterinary and Animal Sciences (LUVAS), Hisar, Haryana, India.
Microsc Res Tech. 2024 Sep;87(9):2241-2249. doi: 10.1002/jemt.24585. Epub 2024 May 9.
At 22nd day of fetal development, the primordial anlage of mandibular gland was first noticed as a solid epithelial bud from oral epithelium. The terminal buds were arranged in the form of clusters with undifferentiated epithelial cells and terminated in a bulb like structure in 28-day-old fetus. The lumenization and branching of the main cord was noticed at 35th day. The primary septa, which divide the glandular mass into lobes was observed from 53rd day onwards which resulted in the formation of distinct lobulation at 58th day. At 61st day, the capsule formation was initiated by the aggregation of mesenchymal tissue. The terminal tubules differentiated to form the secretory end pieces and the tubular portion leads to the formation of intercalated and striated ducts at 98th day. Predominantly mucous types of acinar cells were seen from 108th day onwards. The number of lobules increased with steep increase in parenchyma from 128th day onwards. Micrometrical studies revealed that the mean diameter of acinar cells and all ducts was increased with the advancement of age and the significant differences were observed between groups. Localization of acidic and neutral mucopolysaccharides was observed in mucous cells and goblet cells. RESEARCH HIGHLIGHTS: The primordial anlage of mandibular salivary gland was seen at 22nd day. Lobulation of gland was appeared at 53rd day of development, however; it was completed at 58th day. At 98th day, the terminal tubules differentiated to form the secretory end pieces. The parenchyma of the gland showed predominantly mucous type of cells from 108th day onwards. Myoepithelial cells were first appeared as flattened basal cells initially around the developing acinar cells at 132nd day. Localization of acidic as well as neutral mucopolysaccharides was observed in mucous cells and goblet cells. Fine lipid droplets were observed in intralobular as well as interlobular connective tissue, however; phospholipids were observed in the cell membrane of secretory cells and ducts.
在胎儿发育的第22天，下颌腺的原基首次被发现为口腔上皮的一个实性上皮芽。终末芽由未分化的上皮细胞呈簇状排列，并在28日龄胎儿中终止于一个球状结构。在第35天观察到主索的管腔化和分支。从第53天开始观察到将腺块分成叶的初级隔膜，这导致在第58天形成明显的小叶。在第61天，间充质组织聚集开始形成被膜。在第98天，终末小管分化形成分泌末端，管状部分导致闰管和纹状管的形成。从第108天开始可见主要为黏液型的腺泡细胞。从第128天开始，小叶数量随着实质的急剧增加而增加。显微测量研究表明，腺泡细胞和所有导管的平均直径随着年龄的增长而增加，并且在各年龄组之间观察到显著差异。在黏液细胞和杯状细胞中观察到酸性和中性黏多糖的定位。研究亮点：下颌唾液腺的原基在第22天可见。腺体在发育的第53天开始出现小叶化，然而，在第58天完成。在第98天，终末小管分化形成分泌末端。从第108天开始，腺体实质主要显示为黏液型细胞。肌上皮细胞在第132天首先作为扁平的基底细胞出现在发育中的腺泡细胞周围。在黏液细胞和杯状细胞中观察到酸性和中性黏多糖的定位。在小叶内和小叶间结缔组织中观察到细小的脂滴，然而，在分泌细胞和导管的细胞膜中观察到磷脂。
