Definition: the esophagus is a narrow fibromuscular tube which is flattened anteroposteriorly. It connects the pharynx with the stomach.
Measurement: it’s 25 to 30cm long and extends from the cricoid cartilage at the level of C6 vertebra to the cardiac orifice of the stomach at the level of T10 vertebra.
Parts: it’s divided into
a. Cervical part
b. Thoracic part
c. Abdominal part
Thoracic esophagus: this part transverses, first the superior and then the posterior mediastinum.
anteriorly: it is crossed by the trachea, the left bronchus, the pericardium and the diaphragm
posteriorly: lie the thoracic vertebra, thoracic duct, the azygos vein and near the diaphragm, the descending aorta.
left side: it is related to the left subclavian artery, aortic arch, left recurrent laryngeal nerve, thoracic duct, and pleura. In the posterior mediastinum it relates to the descending thoracic aorta.
right side: here it relates to the pleura and azygos vein.
Structure: the wall consists of outer longitudinal layer and inner circular layer of smooth muscle. Surface epithelium of mucous membrane is stratified squamous.
Blood supply: the thoracic esophagus is supplied by branches from the inferior thyroid artery and esophageal branches from the aorta. Veins drain to the azygos veins.
Lymph drainage: from periesophageal lymph plexus into the mediastinum nodes
Nerve supply: by recurrent laryngeal nerve and sympathetic fibres from middle cervical ganglion. Motor and secretomotor fibres are supplied by the vagus.