Anatomy of Esophagus Curvatures Constrictions Anatomical Relations Sphincters Arterial Supply Venous drainage Nerve supply Histology

1. ANATOMY OF ESOPHAGUS
Dr. Manahil Jamil

2.  Esophagus is a soft muscular tube that allows food to pass from pharynx to the
stomach
 It is Collapsed at rest
 begins at the inferior border of the cricoid cartilage (C6), extending to the cardiac
orifice of the stomach (T11)
 DIMENSIONS
 Length : 25 cm
 Width : 2 cm
 Lumen : It’s flattened anteroposteriorly.
• Normally it’s closed (collapsed) and opens (dilates) only during the passage of
the food.

3. PARTS OF ESOPHAGUS

4. CURVATURES
 Two anteroposterior curvature
1. First corresponding to the curvature of cervical spine.
2. Second corresponding to the curvature of thoracic spine.
 Two side-to-side curvatures – both in the direction of the left
1. First at the root of the neck, before entering the thoracic inlet.
2. Second at the level of T7 vertebra, before passing in front of the descending
thoracic aorta.

6. CONSTRICTIONS
The distance of each constriction is measured from the upper incisor teeth
First constriction
(cervical)
at the pharyngo- esophageal
junction (at C6)
9 cm (6 inches) from the
incisor teeth
Second constriction
(thoracic)
crossed by the arch of aorta
(at T4)
22.5 cm (9 inches) from
the incisor teeth
Third constriction
(thoracic)
crossed by the left principal
bronchus (at T5-T6)
27.5 cm (11 inches) from
the incisor teeth
Fourth constriction
(diaphragmatic)
pierces the diaphragm (at
T10)
40 cm (15 inches) from the
incisor teeth

10. ESOPHAGEAL SPHINCTERS
 UPPER ESOPHAGEAL SPHINCTER
• An anatomical, striated muscle sphincter at the junction between the pharynx and
esophagus
• It is made by the cricopharyngeal muscle.
• Normally, it is constricted to prevent the entrance of air into the esophagus.
 LOWER ESOPHAGEAL SPHINCTER
• Physiological sphincter located in the gastro-esophageal junction (junction between the
stomach and esophagus).
• The sphincter is classified as a physiological (or functional) sphincter, as it does not have
any specific sphincteric muscle.
• Instead, the sphincter is formed from four phenomena:
1. The esophagus enters the stomach at an acute angle.
2. The walls of the intra-abdominal section of the esophagus are compressed when
there is a positive intra-abdominal pressure.
3. The folds of mucosa present aid in occluding the lumen at the gastro- esophageal
junction.
4. The right crus of the diaphragm has a “pinch-cock” effect.

11. ARTERIAL SUPPLY AND VENOUS DRAINAGE

13. HISTOLOGY

16. THANK YOU