Anatomy of tracheobroncial tree

anatomy which is relevant for the medical and allied healthcare professionals.

1. ANATOMY OF TRACHEOBRONCIAL
TREE
By,
Dr. Arun Kumar
Dept of Anesthesiology
YMC.
Moderator: Dr. Harish Hegde.

3. TRACHEA

4. TRACHEA
•Extends from lower border of cricoid cartilage.
•At the level of C6 vertebra.
•Length of about 15-20 cm.
•Intermittently strengthened by cart. Rings.
•At 6
TH
tracheal ring it goes intrathoracic.
•At the level of T5( angle of louis, 2
nd
intercostal
space), bifurcation occurs.
•Right and left bronchus.

6. THE BRONCHUS
•Left and right bronchus.
•Adults right is shorter and in a more acute angle.
(hence ETT, suctioning, foreign body enters
easily).
•Its still out of lung parenchyma, right 2.5cm, left
5cm.
•Right divides into 3 branches and left 2.
•Futher division to medium, small bronchi(0.8-
4mm), and bronchioles(0.8mm)

8. THE BRONCHIOLES
•Branches from bronchus with diameters
<0.8mm.
•Do not have cartilages.
•Classified into 2 types: terminal and respiratory.
•Terminal: each of these leads to 3 resp.
bronchioles -> 4 generations of alveolar ducts.

10. ALVOELI
•Site of gas exchange.
•Formed of single layer of cells.
•Pneumocytes I, II.
•Other cells pulm macrophages, mast cells,
lymphocytes.
•Bound by tight gap junctions.
•Supported by elastic connective tissue.
•Avg diameter 0.05- 0.33mm.
•Sorrounded by pulm vessels.

12. CARTILAGES
•The cartilages in the trachea is of hyaline,
•Its semicircular, deficient posteriorly,
•Ends connected by a fibroelastic band.
•Primary function: to prevent collapse of the
trachea.
•Splits at the carina to cover the bronchus.
•As bronchi becomes intrapulmonary, it changes
discretely into cartilage plates.
•Dissappears in airway of diameter <0.6mm.

13. MUSCLE
•2types inner circular, outer longitudinal(predominant in
children).
•Distributed in a geodesic network like pattern.
•Striated. Autonomic innervation (bronchodialator symp)
•Primary function: change size of tube during stages of
respiration.
•It becomes thinner with division but relative thickness
increases.
•Highest in terminal bronchioles: prolonged spasm. Autonomic
innervation.

14. Epithelium and defence mech.
•Lined by columnar pseudostratified epithelium.
•Namely goblet, serous, ciliated cells mainly
produce mucus.
•No mucus glands in bronchioles.
•Ciliated epithelium brushes mucus out of the
airway.
•?K-cells, clara cells- supportive.
•Lymphocytes, “globule” lymphocyes: defence.

15. Blood supply
•Mainly by the bronchial arteries. 1 to left side, 2
to right.
•Left arises from ant. Aspect of descending aorta.
•Right has variable origins: 1/3 intercostal,
rt.subclavian, internal thoracic arteries.
•Has good anastomoses in the adventitia of the
bronchus.
•Venous plexuses drain airway to bronchial->
azygous -> hemiazygous-> intercostal veins.

17. BRONCHO PULMN. SEGMENTS
•It is a unit of lung parenchyma, distinct with its
own segmental bronchus and a pulmonary
artery, which is separated from the other by
septa.
•Totally 20 present.
•Divided by the brochus which enters the lung.

18. Right side
•3 segmental bronchi:
•UPPER: 1. Apical, 2. posterior, 3. anterior.
•MIDDLE: 1. lateral, 2. medial.
•LOWER: 1. apical, 2.medial basal(cardiac),
3.ant.basal, 4. post. Basal, 5. lat. Basal.

20. Left side
•UPPER: 1. apical, 2. posterior 3. Anterior.
•LINGULAR: 1. superior, 2. Inferior.
•LOWER: 1. apical, 2. ant.basal, 3. post.basal, 4.
lat.basal.

22. Brocho pulmn segments contd.
•This anatomical division has made lung
resection surgeries easier.
•Lung radiodiagnosis.
•postural drainage.
•Visualising the interiors of the bronchi.
•Infections of the segments remains restricted to
it.

23. •Benumoff textbook of airway management.
•Miller textbook of anesthesia 7
th
edition.
•Morgan, clinical anesthesiology 4
th
edition.
•Ellis, Feldman, Griffith:Anatomy for
anesthesiologists.
•BD Chaurasia, human anatomy 4
th
edition.
•World wide web.