Klećkowska-Nawrot J, Dziegiel P
Department of Anatomy and Histology, Faculty of Veterinary Medicine, University of Environmental and Life Sciences in Wrocław, ul. Kozuchowska 1/3, 51-631 Wrocław, Poland.
Anat Histol Embryol. 2007 Dec;36(6):428-32. doi: 10.1111/j.1439-0264.2007.00780.x.
The morphological and histological examinations of the third eyelid and superficial gland of the third eyelid were conducted in pig fetuses coming from the 20th, 24th, 27th, 30th, 35th, 50th, 63rd, 94th and 112th day of gestation. The morphological examinations were carried out by applying the method of macroscopic preparation with a forehead magnifying glass and binocular (magnification 1.5-5.0x). In order to make anatomical elements more visible, 60-80% absolute alcohol and 0.5-4% acetic acid solution were used for the examinations. On the 20th, 24th, 27th and 30th day of gestation, the whole fetuses were collected for the histological examinations. The whole eyeball with developing accessory organs was collected from the pig fetuses on the 35th day of gestation. On the 50th, 63rd, 94th and 112th day of gestation, only the superficial gland with the third eyelid was collected. Staining with haematoxylin-eosin (H-E) and Azan method was performed. On the 20th, 24th, 27th and 30th day of gestation, the primordia of the glandular epithelium were not found in the examined material. The process of the third eyelid and superficial gland formation starts on the 35th day of gestation. On the 50th and 63rd day of gestation, the gland surrounding the cartilage of the third eyelid is composed of the high amount of loose connective tissue and gland cells which give rise to excretory segments. On the 94th day of gestation, the gland lobes become visible, the efferent ducts form. On the 112th day, the cartilage of the third eyelid assumes the appearance of the mature hyaline cartilage. The excretory segments are composed of simple cuboid epithelium with a large, round nucleus arranged less or more peripherally. Their number increases 2- or even 3-fold at the end of gestation.
对妊娠第20、24、27、30、35、50、63、94和112天的猪胎儿进行第三眼睑和第三眼睑浅表腺体的形态学和组织学检查。形态学检查采用前额放大镜和双目镜（放大倍数1.5 - 5.0倍）进行宏观标本制备的方法。为了使解剖结构更清晰可见，检查时使用60 - 80%的无水乙醇和0.5 - 4%的醋酸溶液。在妊娠第20、24、27和30天，收集整个胎儿进行组织学检查。在妊娠第35天，从猪胎儿中收集带有发育中附属器官的整个眼球。在妊娠第50、63、94和112天，仅收集带有第三眼睑的浅表腺体。采用苏木精 - 伊红（H - E）染色和阿赞染色法。在妊娠第20、24、27和30天，在所检查的材料中未发现腺上皮原基。第三眼睑和浅表腺体的形成过程始于妊娠第35天。在妊娠第50和63天，围绕第三眼睑软骨的腺体由大量疏松结缔组织和产生排泄段的腺细胞组成。在妊娠第94天，腺叶可见，传出导管形成。在妊娠第112天，第三眼睑软骨呈现成熟透明软骨的外观。排泄段由单层立方上皮组成，细胞核大而圆，或多或少排列在周边。在妊娠末期，它们的数量增加2倍甚至3倍。
