Esophagus (Abdominal Portion)
The esophagus is a muscular, collapsible
tube about 10 in. (25 cm) long that joins the
pharynx to the stomach.
The greater part of the esophagus lies
within the thorax.
The esophagus enters the abdomen through
an opening in the right crus of th diaphragm.
After a course of about 0.5 in. (1.25
cm), it enters the stomach on its right side.
Relations
The
esophagus is related : anteriorly to the posterior surface of the left
lobe of the liver.
posteriorly to the left crus of the diaphragm.
The
left and right vagi lie on its anterior and posterior surfaces, respectively.
Blood
Supply
Arteries
The arteries are branches from the
left gastric artery.
Veins
The veins drain into the left
gastric vein, a tributary of the portal vein.
Lymph
Drainage
The lymph vessels follow the
arteries into the left gastric nodes.
Nerve
Supply
The nerve supply is the anterior and
posterior gastric nerves (vagi) and sympathetic branches of the thoracic part
of the sympathetic trunk.
Function
The esophagus conducts food from the
pharynx into the stomach.
Wavelike contractions of the
muscular coat, called peristalsis, propel the food onward.
Gastro
esophageal Sphincter
No anatomic sphincter exists at the
lower end of the esophagus. However, the circular layer of smooth muscle in
this region serves as a physiologic sphincter.
As the food descends through the esophagus,
relaxation of the muscle at the lower end occurs ahead of the peristaltic wave
so that the food enters the stomach.
The tonic contraction of this
sphincter prevents the stomach contents from regurgitating into the esophagus.
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