Book 4 - Self Instructional Manual for Cancer Registrars - SEER ...

EsophagusThe esophagus is a muscular tube about ten inches (25 cm.) long extending from the hypopharynxto the stomach. The peristaltic 1 motion of the esophagus moves food along to the stomach. Theesophagus lies posterior to the trachea and the heart, and passes through the mediastinum and thehiatus, an opening in the diaphragm, in its descent from the thoracic to the abdominal cavity. Theesophagus can be divided into three segments or regions: 1) cervical, 2) thoracic, and 3) abdominal.The location of esophageal lesions is frequently measured from the incisors (front teeth) and may beapproximated as follows:• The cervical esophagus begins at the lower border of the cricoid cartilage and ends at thethoracic inlet (suprasternal notch) approximately 18 cm measuring from the upper incisors.• The upper thoracic esophagus extends from the thoracic inlet to the level of the trachealbifurcation, approximately 24 cm from the upper incisors.• The mid-thoracic portion is the proximal half of the esophagus between the trachealbifurcation and the esophago-gastric junction. The lower level is approximately 32 cmfrom the upper incisor teeth.• The lower thoracic portion, 8 cm in length (includes the abdominal esophagus), is thedistal half of the esophagus between the tracheal bifurcation and the esophago-gastricjunction, approximately 40 cm from the upper incisor teeth.The esophagus may also be described in terms of upper, mid, and lower thirds. This measurementis not equivalent to the one just described as you can see from Figure 31. It may be approximatedas follows:• The upper (proximal) third extends from the sixth cervical vertebra to the sixth thoracic vertebra.• The mid third extends from the sixth thoracic vertebra to the ninth thoracic vertebra.• The lower (distal) third extends from the ninth thoracic vertebra to the cardioesophagealjunction.Figure 30. DMSIONSOF THE ESOPHAGUS117Pophsrfm_;! (?1peristalsis (n); peristaltic (adj)--Wavelike, involuntary contractions provided by the combinationof longitudinal and circular muscles which propel the contents of the gastrointestinal tract.2O3