Trachea- anatomy and histology

1. Trachea and Bronchi
Dr. Mohanad

2. 2
Trachea (windpipe): Landmarks
 Begins at lower border of Cricoid Cartilage / C6
 Extends to Carina
 Lined by ciliated columnar epithelium
 Length: 9-15 cm long / 2cm in diameter
 15 – 20 incomplete rings of cartilage
 Bridged post. by trachealis muscle

3. 3
Tracheobronchial Anatomy

4. 4
Cricoid
Cricoid Cartilage
Cricothyroid
membrane
Thyroid gland
Thyroid
cartilage
Cricoid
cartilage

5. 5
Trachea
 Variable shape
 Usually round, oval, oval with flattened post.
border
 Square
 Inverted pear
 Horseshoe
 Very pliable in children
 May deviate to the right at almost 90° in normal
expiratory film.

6. 6
Trachea: Carina
 Ridge on internal aspect
of last tracheal cartilage
 Right of the midline
 Lies at T5 level: T4 on inspiration / T6 on
expiration
 Normal angle: 65°
 Angle increases by 10° - 15° in recumbency
(relaxing)
 Angle slightly larger + symmetrical in children

7. 7
Carina
Mucosa highly sensitive
to irritants: Cough reflex
*

8. 8
Main carina:
Concepts of anterior and posterior

9. 9
Relations: Cervical
 Anterior:
 Isthmus anterior to 2nd,
3rd, 4th rings
 Inferior thyroid veins
 Strap muscles:
Sternohyoid, Sternothyroid
 Posterior:
 Oesophagus, recurrent
laryngeal nerves
 Lateral:
 Lobes of thyroid
 Common carotid artery

10. 10
Relations: Thoracic
 Anterior:
 Brachiocephalic a.
 Left common carotid
a.
 Left brachiocephalic
v.

11. 11
Relations: Thoracic
 Posterior:
 Oesophagus
 Left recurrent laryngeal
n.

12. 12
Blood supply
 Upper trachea
 Inferior thyroid artery
 Lower part
 Branches of the
bronchial artery
 Venous drainage
 Inferior thyroid
venous plexus

14. Trachea
 Lined with respiratory
epithelium (ciliated
pseudo-stratified
columnar epithelium.)
 “C”-shaped pieces of
hyaline cartilage
protecting airway while
allowing for swallowing
 Trachealis muscle
(smooth muscle) runs
across posterior wall of
trachea connecting ends
of tracheal cartilage

15. Trachea
Low power
Medium power
High power

16. Pseudostratified
Ciliated columnar
epithelium
Loose
connecti
ve tissue
Hyaline cartilage
Connective tissue
TRACHEA

17. Bronchus
 Two principal bronchi begin at
bifurcation of trachea
 Each bronchi subdivides into
successive generations of smaller
bronchi and reach the lung
 Each bronchus consists of extra-
pulmonary and intra-pulmonary part

18. Right Bronchus
 It is wider ,shorter and more
vertical
 Wider because supplies more
voluminous air, vertical because
trachea bifurcation deviates more
to right side
 Foreign body in the trachea is
usually aspirated more to the right
side
 It enters the root of the right lung
and reaches the Hilum at the level
of 5th
thoracic vertebrae

19. Left Bronchus
 Longer, narrower and more oblique than right bronchus
Extra-pulmonary part
 5 cm in length
 It enters the lung at the hilum at the level of 6th
thoracic
vertebrae.
Intrapulmonary part
 The left principal bronchus divides into upper and lower
bronchi to supply the respective lobe of left lung.
 It divides into ascending and descending branches which
supply the bronchopulmonary segments.

20. Pulmonary bronchi
 Within the lung, the principal bronchus divides into
secondary or lobar bronchi
Each secondary bronchus divides
Into Segmental or Tertiary Bronchi.
The area of the lung aerated by a
tertiary bronchus is known as
Bronchopulmonary segment.

24. Intrapulmonary bronchus

27. Ciliated cells
Basal cells
 Goblet cells
Brush cells
Small granule cells
Clara cells
Cells types found in Luminal Epithelium of Bronchioles

28. BRONCHIOLE