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The esophagus is a tubular, elongated organ of the digestive system that connects the pharynx to the stomach (see Images. Digestive and Respiratory Structures Anatomically Related to the Esophagus; Muscles of the Cheek and Pharynx; Posterior View of the Pharynx, Esophagus, and Thoracic Structures). Food passes through the esophagus to reach the stomach for further digestion. This tubular organ follows a course posterior to the trachea and heart, anterior to the spinal column, and traverses the diaphragm before entering the stomach.[1][2] The esophagus is divided into 3 anatomical segments: cervical, thoracic, and abdominal. The cervical segment begins at the cricopharyngeus and terminates at the suprasternal notch. This section lies just posterior to the trachea and is joined to it via loose connective tissue. Posteriorly, the prevertebral fascia connects the esophagus to the bodies of the 6th through 8th cervical vertebrae. The thoracic duct courses along the left side of the cervical esophagus near the 6th and 7th cervical vertebrae.[3] Laterally, the carotid sheath and the lower poles of the lateral thyroid gland are adjacent to the esophagus in the lower neck. The thoracic segment extends from the suprasternal notch to the diaphragm, occupying the space between the vertebral column and the trachea in the superior mediastinum. Distally, the esophagus passes posterior to the aortic arch at the level of the T4–T5 intervertebral discs and enters the posterior mediastinum. The abdominal segment of the esophagus extends from the diaphragm to the cardia of the stomach.[4] This portion passes through the esophageal hiatus, formed by the right crus of the diaphragm at approximately the T10 vertebral level, and terminates at the cardia, typically at the level of T11. The organ is typically 9 to 10 in (23–25 cm) long in fully grown adults. Sphincters are present at both proximal and distal extremities. The lumen is lined with mucosa and supported by connective tissue, with an outer layer of smooth muscle. The upper esophageal sphincter (UES), located proximally, permits unidirectional passage of food into the organ, whereas the lower esophageal sphincter (LES), located distally, allows unidirectional passage of food into the stomach.[5][6][3]