The Esophagus

The Esophagus
is a long muscular tube approximately 40 cm from the incisor teeth (25 cm from cricopharyngeus ) ,that extends from the pharynx at the level of 6th. Cervical vertebra to the stomach ,which it joins opposite the body of 11th. thoracic vertebra.It is arbitrary divided into Cervical ,Thoracic and Abdominal parts.
The esophagus has three distinct areas of naturally occurring anatomic narrowing :-1-The crico pharyngeal constriction
2-Broncho aortic constriction .
3-The diaphragmatic constriction .
Blood supply :-
Cervical esophagus Inf.thyroid Ar.
Thoracic esophagus esophageal branches (Aorta)and segmental vessels (intercostal & phrenic) .
Venous drainage:-
Cervical esophagus inferior thyroid &vertebral V.
Thoracic esophagus azygous & hemi azygous
Abdominal esophagus gastric veins
Lymphatic :- regional lymph nodes ,The flow of the upper 2/3 is upward while the flow of the lower 1/3 is downward.
Nerve supply :- the nerve supply to the normal esophagus is cholinergic and causes contraction every where except for the circular muscle of the cardia where its adrenergic and causes relaxation .
Esophageal Hiatus :-It is a sling of muscle fiber that arises from the right crus in approximately 45% of the patients , however both right and left crus contribute to the hiatus Physiology :- It is a muscular tube that begins proximally with upper esophageal sphincter (UES) and ends distally with lower esophageal sphincter (LES) .Its function is to transport the swallowed material from the pharynx down to the stomach