Histology and Cytology Department, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt.
Anat Histol Embryol. 2021 Sep;50(5):788-800. doi: 10.1111/ahe.12721. Epub 2021 Jun 28.
The oesophagus is a muscular tube comprised of cervical and thoracic regions. Several studies have clarified the histological structure of the oesophagus. However, its histoarchitecture in relation to variable dietary habits of each species is still unclear. In the current study, 21 pigeons, cattle egrets and ducks, n = 7, each was used. Macroscopically, the oesophagus of cattle egrets either the cervical or thoracic parts was the longest among the pigeons and ducks. Histologically, the oesophagus comprised of four distinct tunicae: mucosa, propria submucosa, musculosa and adventitia or serosa. A great structural variation in these layers among the three investigated species was recorded. In the cervical oesophagus of pigeons, the superficial squamous cells showed perinuclear halo zone, the propria submucosa was characteristically lacked any gland. Moreover, its musculosa was very thick. On the other hand, the intraepithelial glands were characteristically distributed along the whole length of the cattle egret's oesophagus. Interestingly, the cervical esophagus of the ducks showed submucosal associated lymphatic tissue; diffuse and nodular Ultrastructurally, the oesophageal glands showed secretory granules of variable electron densities, electron-lucent in the pigeons and ducks and electron-dense in the cattle egrets.
食管是由颈部和胸部区域组成的肌肉管。多项研究已经阐明了食管的组织学结构。然而，其与每种物种不同饮食习惯有关的组织架构仍然不清楚。在本研究中，使用了 21 只鸽子、牛背鹭和鸭子，每组 7 只。宏观上，牛背鹭的食管颈部或胸部部分在鸽子和鸭子中最长。组织学上，食管由四个不同的膜组成：黏膜、固有黏膜下、肌层和外膜或浆膜。在这三种研究物种中，这些层之间存在很大的结构变异。在鸽子的颈部食管中，浅层的鳞状细胞显示核周晕带，固有黏膜下特别缺乏任何腺体。此外，它的肌层非常厚。另一方面，牛背鹭的食管上皮内腺体特征性地分布在整个食管长度上。有趣的是，鸭子的颈部食管显示黏膜相关淋巴组织；弥漫性和结节状超微结构上，食管腺显示出具有不同电子密度的分泌颗粒，在鸽子和鸭子中为电子透明，在牛背鹭中为电子致密。
