Fasferiorly
L Oesophagus.
2 Vertebral column.L Right lung and pleura.
(^2) Right vagus.
3 Azygos vein (Fig.20.2).
An the I'eft
L Arch of aorta, left common carotid and left sub-
clavian arteries.
2 Left recurrent laryngeal nerve (Fig.20.3).
Structure
The trachea has a fibroelastic wall supported by a
cartilaginous skeleton formed by C-shaped rings. The
rings are about 76 to 20 in number and make the tube
convex anterolaterally. Posteriorly there is a gap which
is closed by a fibroelastic membrane and contains
transversely arranged smooth muscle known as the
trachealis. The lumen is lined by ciliated columnar
epithelium and contains many mucous and serous
glands.
Arterial S lV
Inferior thyroid arteries.
Venous Drain e
Into the left brachiocephalic vein.
Oesophagus
Trachea
Right vagus
Right brachiocephalic vein
Left brachiocephalic vein
Superior vena cava
Right phrenic nerve
Pericardium
Root of right lung
Diaphragm
lnferior vena cava
Oesophagus with
oesophageal plexus
around it
Fig.2O.2: Mediastinum as seen from the right side
TRACHEA, OESOPHAGUS AND THORACIC DUCT
Trachea
Oesophagus
Thoracic duct
Arch of aorta
Left
Left phrenic
Diaphragm
Fig. 20.3: Mediastinum as seen from the left side
To the pretracheal and paratracheal nodes.
I Parasympathetic: Nerves through vagi and recurrent
laryngeal nerves. It is:
a. Sensory and secretomotor to the mucous
membrane.
b. Motor to the trachealis muscle.
2 Sympathetic: Fibres from the middle cervical
ganglion reach it along the inferior thyroid arteries
and are vasomotor.
In radiographs, the trachea is seen as a vertical
translucent shadow due to the contained air in
front of the cervicothoracic spine (Fig. 21,.1,2).
Clinically the trachea is palpated in the supra-
sternal notch. Normally it is median in position.
Shift of the trachea to any side indicates a
mediastinal shift.
During swallowing when the larynx is elevated,
the trachea elongates by stretching because the
tracheal bifurcation is not permitted to move by
the aortic arch. Any downward pull due to sudden
and forced inspiration, or aortic aneurysm will
produce the physical sign known as 'tracheal tug'.
Tracheostomy: It is a surgical procedure which
allows air to enter directly into trachea. It is done
Left recurrent
laryngeal nerve
Left subclavian
artery
Left common
carotid artery
Left superior
intercostal vein