Abood Dhyaa Ab, Dawood Mohammed Sulaiman
Department of Anatomy and Histology, College of Veterinary Medicine, University of Baghdad, Baghdad, Iraq.
Open Vet J. 2025 Sep;15(9):4432-4440. doi: 10.5455/OVJ.2025.v15.i9.50. Epub 2025 Sep 30.
The esophagus is vital for the efficient transport of food from the mouth to the stomach. It features mucous membrane and muscle fiber layers that are essential for generating powerful peristaltic movements to propel food forward. Additionally, the inner lining of the esophagus comprises specialized epithelial cells specifically designed to handle the passage of both rough and smooth food types with ease.
The current study was aimed as a comparative model for investigating the changes that occur in the esophagus cytoarchitecture of the same animal species.
Tissue specimens were processed according to the protocol of the paraffin embedding technique and stained with hematoxylin and eosin and Masson's streptomycin (Masson's trichrome).
In this study, the esophagi of lactating, weaned, and adult cats were used to investigate histological and histochemical features. The esophagus wall of lactating kittens revealed immature cytoarchitecture of all tunicae with little mucosal folds covered by proliferating epithelial cells, the muscularis mucosa was absent, and the muscularis externa comprised a bilayer of newly differentiating smooth myofibers. In weaned kittens, the esophagus had a slightly thickened wall, the mucosa of the cervical and thoracic segments had long folds, and the thoracic and abdominal segments revealed differentiation of the muscularis mucosa and skeletal muscle fibers, which differentiated in the cervical and thoracic segments, while the muscularis revealed smooth muscle bundles in the abdominal segments. In mature cats, the mucosa of the entire length of the esophagus comprised enlarged mucosal folds that were covered by very thick stratified squamous cells. The lamina propria submucosa had no esophageal glands. Muscular mucosa was absent in the cervical segment, whereas it was observed in the thoracic and abdominal segments. The muscularis externa at the neck and chest segments of the esophagus is constructed of inner circular and outer longitudinal bundles of skeletal muscle, whereas it turns into smooth muscle fibers in the abdominal segment. The statistical analysis of the data revealed significant differences in fold height and epithelium, fold thickness, and tunica muscularis among segments in weaned, lactating, and adult cats.
The current study concluded that the cat esophagus was not a glandular part of the gastrointestinal tract compared with other mammals, which makes this species a reliable experimental model of digestive tissue, and explained the role of the pharyngeal or oral part of the digestive system in the lubrication of the upper digestive tract.
食管对于将食物从口腔有效运输到胃至关重要。它具有黏膜和肌纤维层,这些对于产生强大的蠕动运动以推动食物前进至关重要。此外,食管的内衬由专门的上皮细胞组成,这些细胞经过特殊设计,能够轻松处理粗糙和顺滑食物类型的通过。
本研究旨在作为一个比较模型,用于研究同一动物物种食管细胞结构的变化。
组织标本按照石蜡包埋技术的方案进行处理,并用苏木精和伊红以及马松三色染色法染色。
在本研究中,使用哺乳期、断奶期和成年猫的食管来研究组织学和组织化学特征。哺乳期小猫的食管壁显示所有膜层的细胞结构不成熟,黏膜褶皱很少,被增殖的上皮细胞覆盖,黏膜肌层缺失,外肌层由新分化的平滑肌纤维双层组成。在断奶小猫中,食管壁略有增厚,颈部和胸部段的黏膜有长褶皱,胸部和腹部段显示黏膜肌层和骨骼肌纤维的分化,骨骼肌纤维在颈部和胸部段分化,而腹部段的肌层显示为平滑肌束。在成年猫中,食管全长的黏膜由扩大的黏膜褶皱组成,被非常厚的复层鳞状细胞覆盖。固有层黏膜下层没有食管腺。颈部段没有黏膜肌层,而在胸部和腹部段可以观察到。食管颈部和胸部段的外肌层由骨骼肌的内环和外纵束组成,而在腹部段则变为平滑肌纤维。数据的统计分析显示,断奶、哺乳期和成年猫各段之间在褶皱高度和上皮、褶皱厚度以及肌层方面存在显著差异。
本研究得出结论,与其他哺乳动物相比,猫的食管不是胃肠道的腺性部分,这使得该物种成为消化组织的可靠实验模型,并解释了消化系统的咽部或口腔部分在上消化道润滑中的作用。