The trachea extends from the larynx to the carina where it divides into the two main bronchi. It is composed of C-shaped cartilaginous rings and lined with ciliated epithelium. The right bronchus is wider, shorter and more vertical than the left bronchus. The primary bronchi divide within the lungs to form lobar and segmental bronchi that supply each bronchopulmonary segment. The trachea and bronchi receive their blood supply from branches of the inferior thyroid and bronchial arteries and are innervated by the recurrent laryngeal nerves.

1. ANATOMY OF TRACHEA AND BRONCHI
25/06/1441
Dr Mostafa Kandil MD PhD
1

3. Trachea
The trachea is a
cartilaginous and
membranous
tube, extending from the
cricoid cartilage of the
larynx, on a level with
C6 vertebra, to the
level of the angle of
Louis (T4/5) vertebra,
where it divides at
carina angle into the
two bronchi, one for
each lung.25/06/1441 Anatomy trachea & bronchi 3

4. Trachea
• Structure:
The trachea is a rigid
fibroelastic structure.
Incomplete rings of
hyaline cartilage
continuously
maintain the patency
of the lumen.
• The trachea is lined
internally with ciliated
columnar epithelium.
25/06/1441 Anatomy trachea & bronchi 4

5. Trachea
• It measures about 11
cm. In length.
• Its diameter, from
side to side, is from
2 to 2.5 cm.
• It has 18-22
cartilaginous C
shaped rings
• It is greater in the
male than in the
female.25/06/1441 Anatomy trachea & bronchi 5

6. Trachea
Relations: Anteriorly:
Neck: cervical part
•The isthmus of the thyroid gland
(2nd, 3rd and 4th tracheal rings )
•The inferior thyroid veins
•The sternothyroid and sternohyoid
muscles
Thorax:
•The manubrium sterni
•The remains of the thymus
•The left innominate vein
•The aortic arch
•Left common carotid arteries
•The deep cardiac plexus.
25/06/1441 Anatomy trachea & bronchi 6

7. Trachea
Relations:
Posteriorly : the
esophagus
Laterally:
Neck:
•Common carotid arteries
•Right and left lobes of
the thyroid gland
•Inferior thyroid arteries
•The recurrent nerves
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8. Trachea
Relations: Laterally:
Thorax: it lies in the superior
mediastinum.
Right
• The pleura
• Right vagus,
• The innominate artery
Left
• Left recurrent nerve
• The aortic arch
• The left common carotid
• Subclavian arteries
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9. Inferior thyroida.
Recurrent laryngealn. Thoracicduct
Vagusn.
Sympathetic trunk
Trachea
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10. Trachea
• The trachea divides
into two main bronchi
: the left and the right
bronchi, at the level of
the sternal angle at
the anatomical point
known as the carina.
25/06/1441 Anatomy trachea & bronchi 10

11. TRACHEA
Rt. Main bronchus Lt. Main bronchus
Inf. Lobar
)
Middle
lobar
bronchus(2
)
Sup. Lobar
bronchus(5 bronchus(5
)
Inf. Lobar
bronchus(4
)
• Apical
• Posterior
•Anterior
• Lateral
• Medial
• Superior
•Medial basal
• Ant. Basal
• Post basal
• Lateral basal
• Apical
•Posterior
• Anterior
•Superior lingular
•Inferior lingular
Superior lobar
Bronchus(3)
•Apical
•Ant basal
•Lat basal
•Post basal

12. Bronchopulmonary semgments
3+23
2
5
4
RIGHT(10 LEFT
)

14. Bronchi
The right bronchus:
•Wider, shorter, and
more vertical in
direction than the left.
•It is about 2.5 cm.
Long,
•It enters the right lung
nearly opposite the T5
vertebra.
25/06/1441 Anatomy trachea & bronchi 14

15. Bronchi
The Left Bronchus
•It is smaller in caliber
but longer than the
right
•It is about 5 cm. long.
•It enters the root of the
left lung opposite the
T6 vertebra.
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16. 25/06/1441 Anatomy trachea & bronchi 16

17. trachea
Left
primary
bronchus
Right
Primary
Bronchus
Wider, short
er, and more
vertical than
the left
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21. Structure of a bronchus. Smooth
muscle is present in the entire
bronchiolar tree, including the
respiratory bronchiole.
Contraction of this muscle
induces folding of the mucosa.
The elastic fibers in the bronchus
continue into the bronchiole. The
lower portion of the drawing
represents a region with its
connective tissue removed to
show the presence of elastic
fibers and smooth muscle.

23. Bronchi
• The primary
bronchi divide to
form Secondary
Bronchi (lobar
bronchi).
• There is one
secondary
bronchus for each
lobe of the lungs.
• There are 2 lobes
on the left lung.
• There are 3 lobes
on the right lung.
25/06/1441 Anatomy trachea & bronchi 23

24. Bronchi
• The left main
bronchus enters the
hilum and divides
into a superior and
inferior lobar
bronchus.
• The right main
bronchus gives off
the bronchus to the
upper lobe prior to
entering the hilum
(superior lobar
bronchus) and once
into the hilum divides
into middle and
inferior lobar25/06/1441 Anatomy trachea & bronchi 24

25. Bronchi
• Each lobar bronchus
divides within the lobe
into(Tertiary Bronchi)
segmental bronchi.
• Each segmental
bronchus enters a
bronchopulmonary
segment.
• Each
bronchopulmonary
segment is pyramidal
in shape with its apex
directed towards the
hilum.
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29. Tracheablood supply
• the trachea receives
its blood supply from
branches of the
inferior thyroid and
bronchial arteries.
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30. VASCULAR & NERVE SUPPLY OF
TRACHEA AND BRONCHI
 Arterial supply : Upper 2/3 - Inferior thyroid artery
Lower 1/3 – Bronchial artery
 Venous supply : Inferior thyroid vein
 Lymphatic : drain into Deep cervical, pretracheal, paratracheal LN.
 Nerve supply : RLN with sympathetic fibres from middle cervical ganglion
Bronchial arteries :
 Rt. Bronchial artery - branch of 3rd posterior intercoastal artery.
 2 Lt. bronchial arteries – branch of thoracic aorta.
Bronchial vein communicates with pulmonary vein.
 Rt. Side  Azygous vein
 Lt. Side  Accessory hemiazygous vein

31. Thank you
Anatomy trachea & bronchi25/06/1441 31