Anatomy of esophagus

1. ANATOMY OF ESOPHAGUS
The esophagus is
a tubular muscular
structure,
measuring
approximately 23
cm in length,
which comprises
outer longitudinal
and inner circular
muscle fibres.

2. ANATOMY OF ESOPHAGUS
The proximal part of the
esophagus consists of
striated muscle fibres,
whereas the distal part
is composed of smooth
muscle. The level of the
transition zone between
striated and smooth
muscle is highly
variable, with only the
proximal 4 cm of the
esophagus always
composed of striated
muscle.

3. ANATOMY OF ESOPHAGUS
When the
esophagus is
partially
collapsed, the
normal
longitudinal folds
are seen as
smooth, straight
structures no more
than 1 to 3 mm in
width

4. ANATOMY OF ESOPHAGUS
In some patients, fine
transverse folds may also
be observed in the
esophagus because of
transient contraction
of the longitudinally
oriented muscularis
mucosae. These folds are
almost always found to be
associated with
gastroesophageal
reflux.12

5. ANATOMY OF ESOPHAGUS
In contrast, focally spiculated
transverse folds may be
detected as a normal variant
in upper thoracic esophagus
at the junction of the striated
and smooth muscle near the
level of the aortic arch; these
are thought to result from
localized weakening of the
amplitude of peristalsis in
this region.

6. ANATOMY OF ESOPHAGUS
Finally, in older patients,
small nodules may be
visible on the mucosal
surface of the esophagus
because of glycogenic
acanthosis, a common
degenerative condition
of no clinical
significance

7. ANATOMY OF ESOPHAGUS
Extramural Esophageal Impressions
Extramural esophageal impressions cause smooth
and obtuse impressions on the esophagus similar to
the extramural masses throughout the GI tract.
Most causes are benign. External malignant masses
may ultimately distort the mucosal contour but only
after transmural metastatic invasion.
Benign Malignant
Postcricoid impression,
Cricopharyngeal spasm, Cervical
osteophytic disease, Retropharyngeal
masses (e.g., goiter). Cardiomegaly,
Vascular anomalies (aberrant
vessels, aneurysms, vascular rings),
Mediastinal adenopathy (e.g.,
tuberculosis)
Mediastinal
adenopathy
(metastases)Lung
cancerLung
metastases

8. ANATOMY OF ESOPHAGUS
Postcricoid Impression
Also known as postcricoid
defect of pharyngeal venous
plexus, postcricoid impression
is common and not
pathological, and it is caused
by redundant hypopharyngeal
mucosa overlying the central
pharyngeal venous plexus
positioned approximately at
the level of C6, just below the
cricoid cartilage. It varies in
appearance (sometimes
smooth, sometimes web-like)
and is recognized by its
anterior location on the
esophagus.

9. ANATOMY OF ESOPHAGUS
Cricopharyngeal
Spasm/hypertrophy
This posterior
esophageal impression
is secondary to
hypertrophy and spasm
of the cricopharyngeus
muscle, the lower
portion of the inferior
pharyngeal constrictor
muscle located
posteriorly at the level
of C5-6 vertebral body.

10. ANATOMY OF ESOPHAGUS
Vertebral
Osteophytic
Disease
Anterior vertebral
osteophytes or, rarely,
anterior cervical disc
herniation can cause
discrete posterior
esophageal
indentations, which
are usually smooth
and sometimes
marked

11. ANATOMY OF ESOPHAGUS
Retropharyngeal
Masses
The cervical esophagus
abuts the vertebral
bodies, so pharyngeal
disease that extends
inferiorly and posterior to
the esophagus will
produce esophageal
deviation. Such
retropharyngeal masses
include goiter, abscess,
hematoma,
lymphadenopathy, and
parathyroid enlargement

12. ANATOMY OF ESOPHAGUS
Extrinsic impressions
on the esophagus. A.
Normal
impressions:
1.Aortic arch.
2.Left main bronchus.
3.Heart.
4.Esophageal hiatus.

13. ANATOMY OF ESOPHAGUS
Abnormal
extrinsic
impression on
the posterior
wall of the
esophagus
caused by a
large thoracic
osteophyte.

14. ANATOMY OF ESOPHAGUS
An aberrant right
subclavian artery occurs
in approximately 1 in 200
individuals and is due to
the aberrant origin of the
right subclavian artery,
usually from a left-sided
aortic arch, such that
the vessel now has to
reach the right axilla by
crossing behind the
esophagus at an oblique
angle. Less commonly, it
arises from a right aortic
arch

15. ANATOMY OF ESOPHAGUS
An aberrant left pulmonary
artery is an anomaly resulting
from the left lung being
supplied from the right
pulmonary artery, rather than
the left pulmonary artery.
Because of the location of its
origin, this aberrant left
pulmonary artery has to cross
to the left side of the
mediastinum and in doing so
causes an anterior extrinsic
compression of the thoracic
esophagus at the level of the
carina, giving the name to the
so-called pulmonary sling