Cervical part
Pars cervicalis
- Related terms: Cervical part of esophagus
Definition
The cervical part of the esophagus extends from the pharynx to the thoracic inlet. It is primarily composed of striated muscle fibers, which facilitate voluntary control over the initial phase of swallowing. This segment is positioned dorsally to the trachea and is closely associated with it, which can be relevant in conditions such as tracheal flattening in dogs.[1]
Histologically, the cervical esophagus is lined by non-keratinized stratified squamous epithelium, which provides protection against mechanical damage from ingested food. The submucosa contains esophageal glands that secrete mucus to lubricate the passage of food.[2] The muscularis layer in this region is predominantly striated muscle, which transitions to smooth muscle in the thoracic esophagus.[3]
In cats, the cervical esophagus has a sharp angle at the thoracic inlet, which can predispose to foreign body entrapment.[4]
References
1.Dogs With Severe Tracheal Flattening Exhibit Lower Degrees of Left Lateralization of the Cervical Esophagus.Teshima K, Fujimoto T, Shiozawa N, Ishikawa C, Yamaya Y.The Journal of Veterinary Medical Science. 2024;86(12):1284-1288. doi:10.1292/jvms.24-0270.New Research
2.The Microscopic Anatomy of the Esophagus Including the Individual Layers, Specialized Tissues, and Unique Components and Their Responses to Injury.Zhang X, Patil D, Odze RD, et al.Annals of the New York Academy of Sciences. 2018;1434(1):304-318. doi:10.1111/nyas.13705.
3.A Comparative Histological Study on the Distribution of Striated and Smooth Muscles and Glands in the Esophagus of Wild Birds and Mammals.Shiina T, Shimizu Y, Izumi N, et al.The Journal of Veterinary Medical Science. 2005;67(1):115-7. doi:10.1292/jvms.67.115.
4.Oesophageal Foreign Bodies in Cats: Clinical and Anatomic Findings.Abd Elkader NA, Emam IA, Farghali HA, M DS, Salem NY.PloS One. 2020;15(6):e0233983. doi:10.1371/journal.pone.0233983.
