The document provides detailed information on the anatomy and physiology of the esophagus. It describes the extension, length, diameter and location of landmarks along the esophagus at different ages. It discusses the layers of the muscular coat, sphincters at the upper and lower ends, blood supply, lymphatic and nerve supply. Development, variations and imaging modalities for evaluating the esophagus are also summarized.

1. Dr. Anish Choudhary
MD (Radiology)
VIJAYALAKSHMI HEALTH & HOME
CARE

2.  EXTENSION:
From lower border of cricoid at V C6 level
Passes through diaphragm at V T10 level
Ends at V T11 near cardiac orifice.
 In the newborn:
 Upper limit is at the level of-C4/C5 and
 Lower at T9
 Length:
 At birth: 8-10 cm,
 End of 1st yr: 12cm,
 5th Yr.:16cm
 15th yr: 19cm
 DIAMETRE: 2.5-3cm

3.  At cricopharyngeal
sphincter15cms from
incisors.
 Where aortic arch
crosses22-25cms from
incisors.
 Where it is crossed by left
bronchus27-28cms from
incisors.
 Where it passes through
diaphragm38-40cms
from incisors.

4. CERVICAL OESOPHAGUS:
 Extends from the
pharyngoesophageal
junction to the suprasternal
notch.
 About 4 to 5 cm long.
 At this level, the esophagus
is bordered
anteriorly by the trachea,
posteriorly by the vertebral
column
laterally by the carotid sheaths
and the thyroid gland.

5. THORACIC
OESOPHAGUS:
 Extends from the
suprasternal
notchdiaphragma
tic hiatus.
 Passes posterior to
the trachea, the
tracheal bifurcation,
and the left main
stem bronchus.

6.  The esophagus lies
posterior and to the
right of the aortic
arch at the T4
vertebral level.
 From the level of T8
until the
diaphragmatic hiatus
the esophagus lies
anteriorly to the aorta

7. ABDOMINAL
OESOPHAGUS:
 Extends from the
diaphragmatic
hiatusorifice of
the cardia of the
stomach.
 Forms a truncated
cone, about 1 cm
long.

8.  The muscular coat consists
-external layerlongitudinal fibers
-internal layercircular fibers.
 LONGITUDINAL FIBRES: form a uniform layer that covers
the outer surface of the esophagus.
 CIRCULAR FIBRES: provides the sequential peristaltic
contraction that propels food toward the stomach.
 The circular fibers are continuous with the inferior
constrictor muscle of the hypopharynx.
They run transversely in cranial & caudal regions.
obliquelybody of the esophagus.

9.  The internal muscular layer is thicker than the
external muscular layer.
 Below the diaphragm, the internal circular
musclethickens ,constituting the intrinsic
component of LES.
 Muscular fibers in the cranial partconsist
chiefly striated muscle.
Intermediate partmixed.
Lower partcontains only smooth
muscle.

10.  Two high-pressure
zones prevent the
backflow of food:
 The upper and lower
oesophageal
sphincter.
 Located at the upper
and lower ends of the
oesophagus.

11.  Between pharynx and the
cervical oesophagus.
 Located at C5-C6 level.
 The UES is a
musculocartilaginous
structure.
 Composed of mainly three
muscles: cricopharyngeus,
thyropharyngeus,cranial
cervical oesophagus.

12.  The cricopharyngeus
muscle is a striated
muscle.
 Produces maximum
tension in the A.P
direction and less
tension in lateral
direction.
 Composed of a
mixture of fast- and
slow-twitch fibres.
 This muscle forms the
main component of
UES.

13. Triangular area in the wall
of pharynx b/w
thyropharyngeus and
cricopharyngeus muscles.

14. The lower esophageal sphincter is a high-pressure zone
located where the esophagus merges with the stomach.
Mean pressure here is approx. 8mm Hg.

15.  The LES is a functional unit
composed of an intrinsic and
an extrinsic component.
INTRINSICoesophageal
muscle fibers and is under
neurohormonal influence
EXTRINSICdiaphragm
muscle.
 The endoscopic localization of
the LES is different from the
manometric localization.
 The endoscopic
localizationdetermined by
changes in the esophageal
mucosal transition from
nonstratified squamous
esophageal epithelium to the
gastric mucosa “Z-line”or B
ring.
 Functional location of LES is 3
cm distal to the Z-line.

16. The endoscopic localizationdetermined by changes in the esophageal
mucosal transition from nonstratified squamous esophageal epithelium to the
gastric mucosa “Z-line”or B ring.

17.  The rich arterial supply of
the esophagus is segmental .
 Branches of the inferior
thyroid arteryUES and
cervical esophagus.
 Paired aortic esophageal
arteries or terminal branches
of bronchial
arteriesthoracic
esophagus.
 The left gastric artery and a
branch of the left phrenic
arteryLES and the most
distal segment of the
esophagus.

18.  The venous supply is also
segmental.
 From the dense
submucosal plexus the
venous blood drains into
the superior vena cava.
 Veins of proximal and
distal esophagus
azygous system.
 Veins of mid
oesophaguscollaterals of
left gastric vein.

19.  The lymphatics from
the proximal 1/3rd
drain into the deep
cervical LNs
subsequently into
the thoracic duct.
 Middle 1/3rd  into
superior and
posterior mediastinal
nodes.
 Distal 1/3rd
gastric and celiac
lymph nodes.

20.  Parasympathetic nerve
supply
(SENSORY,MOTOR,SECRE
TOMOTOR)
Upper ½rec.laryngeal
nerve.
Lower ½oesophageal
plexus formed by the 2
vagus plexus.
 The sympathetic nerve
supply(VASOMOTOR)
Upper ½by fibres from
mid cervical ganglion.
Lower ½directly from
upper four thoracic ganglia.

21.  The ganglia that lie between
the longitudinal and the
circular layersmyenteric
or Auerbach's plexus.
 That lie in the submucosa
form the submucous or
Meissner's plexus.
 Auerbach's
plexusregulates
contraction of the outer
muscle layers.
 Meissner's
plexusregulates secretion
and the peristaltic
contractions of the
muscularis mucosae.

22.  At a very early period the stomach is
separated from pharynx by a mere
constriction from primitive pharynx.
This constriction is future esophagus.
 Previous to this elongation the
trachea and oesophagus form a single
structure.
 This becomes divided into two by the
in growth of two lateral septa, which
fuse giving rise to trachea in front
and oesophagus behind.
 At this stage the oesophagus becomes
converted into a solid rod of cells,
losing its tubular nature.
 This eventually becomes canalised to
form a tube

23.  The stratified squamous epithelium of the
oesophagus together with its associated
submucosal glands, is derived from the
endoderm of the foregut.
 The striated muscle of the upper oesophagus is
derived from branchial arches 4 and 6, whereas
the smooth muscle of the lower oesophagus is
derived from somite mesenchyme.
 The myenteric plexus is derived from neural
crest cells.

24. OESOPHAGEAL ATRESIA/TRACHEO-OESOPHAGEAL FISTULA
Due to:
 Spontaneous posterior deviation of oesophago tracheal septum.
 Mechanical factor pushing dorsal wall of foregut anteriorly.

25.  In most circumstances, plain radiographs reveal
little useful information regarding the oesophagus,
except in the context of foreign body ingestion.
 Foreign bodies tend to lodge at one of the
oesophageal constriction points:
• cricopharyngeus;
• aortic arch;
• left main bronchus; or
• diaphragmatic hiatus.

26.  Barium suspensions are
preferred for most
indications; a density of 100%
w/v is often used to provide
a balance between good
mucosal coating and not
being too dense.
 Water-soluble contrast
medium is used initially
when a tear, perforation or
anastomotic leak is suspected.
 Low osmolar agents such as
iopamidol should always be
used to prevent pulmonary
oedema, which can occur
following aspiration of high
osmolar agents such as
meglumine diatrizoate.

27. Oesophagogastroduodenoscopy or
‘endoscopy’
 It is the initial investigation of choice for most
oesophageal indications, particularly dysphagia. It
permits the direct visualisation of the mucosa and,
crucially, biopsies can be taken.
 A wide variety of therapeutic manoeuvres may be
carried out endoscopically. The most common of
these is the treatment of upper GI haemorrhage.
Elective procedures include balloon dilatation
and/or stenting of strictures, radiofrequency
ablation (RFA) of dysplastic or malignant
epithelium and injection of botulinum toxin for
motility disorders..

28.  This technique uses a high-frequency (7–12 MHz)
ultrasound probe mounted at the end of an
endoscope (an ‘echoendoscope’).
 Used for oesophageal cancer staging.
 Used for EUS-guided fine needle aspiration (EUS-
FNA). EUS-FNA allows sampling of structures
deep to the oesophageal mucosa, particularly
thoracic and upper abdominal lymph nodes. This
can be particularly useful in the staging of
oesophageal and lung malignancy, and in the
diagnosis of tuberculosis.

29. Ultrasound
 The majority of the oesophagus is inaccessible to conventional
ultrasound examination. The short cervical and abdominal
segments are amenable to imaging in this way, but this is
rarely used in clinical practice.
CT
 It is most widely used in the staging of oesophageal cancer.
 Intravenous contrast medium should be used whenever
possible, with the upper abdomen imaged in both the arterial
and portal venous phases.
 For the investigation of patients with suspected oesophageal
trauma (including Boerhaave’s syndrome) and in the
postoperative setting, positive oral contrast medium is
required.
MRI
 In current clinical practice, magnetic resonance imaging (MRI)
is not used for imaging the oesophagus.

30.  For patients with oesophageal
cancer, F18- fluorodeoxyglucose
(FDG) PET-CT is now the
standard of care.
 Technetium-based radionuclide
imaging of the oesophagus can be
used for the identification of
oesophageal motility disorders
and gastro-oesophageal reflux
disease (GORD).
 Patients can be imaged
swallowing both liquid and solid
material (usually 99mTc-labelled
sulphur colloid and scrambled
egg, respectively)
Coronal PET-CT image of an FDG-avid
left supraclavicular
lymph node (arrow) metastasis in a
patient with a
distal oesophageal adenocarcinoma.