Oesophagus Anatomy

It is a fibromuscular tube, about 25 cm long in an adult. It
extends from the lower end of pharynx (C6) to the cardiac
end of stomach (T11)

It shows three normal constrictions and it is important to know
their location at oesophagoscopy. They are:
1. At pharyngo-oesophageal junction (C6 )-15 cm
from the upper incisors.
2. At crossing of arch of aorta and left main bronchus
(T 4)-25 cm fronl upper incisors.
3. Where it pierces the diaphragm (T 10)-40 cm from
upper incisors.
Foreign bodies in the oesophagus can be held up at
these constrictions.
The wall of oesophagus consists of four layers. From
within outwards, they are:
(a) Mucosa, which is lined by stratified squamous
epithelium.
(b) Submucosa, which connects mucosa to muscular layer.
(c) Muscular layer, which has inner circular and outer
longitudinal fibres. Circular fibres at the lower end
are thickened to form a cardiac sphincter. The upper
third of oesophagus has striated, the lower third
smooth, and the middle third both striated and
smooth muscle fibres.
(d) Fibrous layer, which forms loose covering of
oesophagus.
Nerve Supply
Parasympathetic fibres come from vagus nerves (X) and
sympathetic fibres from the sympathetic trunk.
Lymphatic Drainage
The cervical, thoracic and abdominal parts drain respectively
into deep cervical, posterior mediastinal and gastric
nodes.