Trachea Flashcards
Describe the trachea.
The trachea is a wide tube lying more
or less in the midline, in the lower part of the neck and
in the superior mediastinum. Its upper end is continuous with the lower end of the larynx.
The trachea is covered by what
By the isthmus of the thyroid
gland and acts as a shield for trachea.
What happens at the lower end of the trachea.
The trachea ends by dividing into the right and left
principal bronchi.
Length of trachea
10-15cm long.
Its external diameter measures about 2 cm in males and about
1.5 cm in females.
Relations of the trachea
Anteriorly
1 Manubrium sterni
2 Sternothyroid muscles
3 Remains of the thymus
4 Left brachiocephalic and inferior thyroid veins.
5. Deep cardiac plexus
Posteriorly
1 Oesophagus
2 Vertebral column.
On the Right Side
1 Right lung and pleura
2 Right vagus
3 Azygos vein .
On the Left Side
1 Arch of aorta
2 left common carotid and left subclavian arteries.
3 Left recurrent laryngeal nerve.
Describe the structure of the trachea
The trachea has a fibroelastic wall supported by a
cartilaginous skeleton formed by C-shaped rings.
The trachea is lined by pseudostratified columnar ciliated epithelium.
The rings are about 16 to 20 in number and make the tube
convex anterolaterally.
Posteriorly, there is a gap which
is closed by a fibroelastic membrane and contains
trachealis.
The lumen is lined by ciliated columnar
epithelium and contains many mucous and serous
glands.
Arterial supply
Inferior thyroid arteries.
Venous drainage
The left brachiocephalic vein.
Lymphatic drainage
To the pretracheal and paratracheal
nodes.
Innervation
Parasympathetic: 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.
Clinical correlates
Tracheoesophageal fistula.
What is extent of trachea in supine position?
In the supine position, the trachea extends from the lower part of the larynx, at the level of the C6 vertebra, to its bifurcation into the right and left main bronchi at the level of the T4/T5 vertebrae.
What is tracheostomy?
It is a surgical procedure which allows
air to enter directly into trachea. It is done in cases
of blockage of air pathway in nose or larynx
Extent of trachea in an erect posture
In an erect posture, the bifurcation lies at the lower border of the sixth thoracic vertebra and descends still further during inspiration.
