Anatomy of trachea & lungs

1. ANATOMY OF TRACHEAANDLUNGS
By:
Dr Nassar Ayoub

2. Trachea
The trachea is a
cartilaginous and
membranous
tube, extending from
the cricoid cartilage of
the larynx, on alevel
with C6 vertebra, to the
level of the angle of
Louis (T4/5) vertebra,
where it divides into
the two bronchi, one
for eachlung.

3. Trachea
• Structure:
The trachea is arigid
fibroelastic structure.
Incomplete rings of
hyaline cartilage
continuously maintain
the patency ofthe
lumen.
• The trachea is
lined internally
with ciliated
columnar
epithelium.

4. Trachea
• It measures about11
cm. In length.
• Its diameter, from side
to side, is from 2 to 2.5
cm.
• It has18-22
cartilaginous rings
• It is greater in themale
than in thefemale.

5. Trachea
Relations:
Anteriorly:
Neck:
• Theisthmus of the thyroid gland
(2nd, 3rd and 4th tracheal rings)
• Theinferior thyroid veins
• Thesternothyroid and sternohyoid
muscles
• Thecervical fascia
Thorax:
• Themanubrium sterni
• Theremains of the thymus
• Theleft innominate vein
• Theaortic arch
• Left common carotid arteries
• Thedeep cardiac plexus.

6. Trachea
Relations:
Posteriorly : the
esophagus
Laterally:
Neck:
• Commoncarotid arteries
• Right and left lobes ofthe
thyroid gland
• Inferior thyroidarteries
• Therecurrent nerves

7. Trachea
Relations:
Laterally:
Thorax: itlies in the superior
mediastinum.
Right
• The pleura
• Right vagus,
• Theinnominate artery
Left
• Left recurrent nerve
• Theaortic arch
• Theleft common carotid
• Subclavianarteries

8. Inferior thyroida.
Recurrent laryngealn. Thoracicduct
Vagusn.
Sympathetic trunk
Trachea

9. Trachea
• Thetrachea divides into
two main bronchi : the
left and the right
bronchi, at the level of
the sternal angle at the
anatomical point known
asthe carina.

10. Bronchi
Theright bronchus:
• Wider, shorter, and
more vertical in
direction than theleft.
• It is about 2.5 cm.Long,
• It enters the right lung
nearly opposite the T5
vertebra.

11. Bronchi
TheLeft Bronchus
• It is smaller incaliber
but longer than the
right
• It is about 5 cm.long.
• It enters the root of the
left lung opposite the
T6vertebra.

13. trachea
Left
primary
bronchus
Right
Primary
Bronchus
Wider, short
er, and more
vertical than
the left

14. Bronchi
• Theprimary
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.

15. Bronchi
• Theleft main
bronchus enters the
hilum and divides
into asuperior and
inferior lobar
bronchus.
• Theright 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 lobar bronchi.

16. Bronchi
• Eachlobar bronchus
divides within thelobe
into(Tertiary Bronchi)
segmental bronchi.
• Eachsegmental bronchus
enters a
bronchopulmonary
segment.
• Eachbronchopulmonary
segment is pyramidal in
shape with its apex
directed towards the
hilum.

19. Tracheablood supply
• the trachea receives its
blood supply from
branches of the inferior
thyroid and bronchial
arteries.

20. Lungs
• Thetwo lungs are
organs of respiration
and lie on either sideof
the mediastinum
surrounded by the right
and left pleuralcavities.
• Right and left lungs.

21. Lungs
• Theright lung is normally
alittle larger than the left
lung becausethe middle
mediastinum, containin g
the heart, bulges more to
the left than to the right.

22. Lungs
Eachlung hasahalf-cone
shape, with a
base,apex, two
surfaces and three
borders:
• Thebase sits on the
diaphragm.
• Theapex projects
above 1st rib and into
the root of theneck.

23. Lungs
• Thetwo surfaces-thecostal
surface lies immediately
adjacent to the ribs and
intercostal spacesof the
thoracic wall.
• Themediastinal surface lies
against the mediastinum
anteriorly and the vertebral
column posteriorly and
contains the comma-shaped
hilum of the lung through
which structures enter and
leave.

24. Lungs
• Thethree borders-the
inferior border of the
lung is sharp and
separates the base
from the costal
surface. Theanterior
and posterior borders
separate the costal
surface fromthe
medial surface.
• Unlike the anterior and
inferior borders, which
are sharp, the
posteriorborder is
smooth androunded.

25. LungsRoot and hilum of
lung:
• Theroot of each
lung is ashort
tubular collection
of structures that
together attachthe
lung to structures
inthe mediastinum
.
• Thehilum,
where
structures enter
and leave.

26. Lungs
Structures within
each root and
located inthe
hilum:
• Apulmonary
artery
• Twopulmonary
veins
• Amain bronchus
• Bronchial vessel
• Nerves
• Lymphatics

27. Lungs
Structure
the right lung:
• It is dividedinto
upper, middle and lower
lobes by oblique and
horizontal fissures.
Theleft lung:
• It hastwo lobes,upper
and lower lobes. They
are separated by the
oblique fissure.

28. Lungs
Read about right and left lungs relations and
lungs impressions.

31. Bronchial Tree
• Thetrachea is divided
into 2 bronchi
• Themain bronchus
divides within the lung
into lobar bronchi.
• Thelobar bronchi divide
into segmental bronchi
which supply
bronchopulmonary
segments.
• Eachbronchopulmonary
segment, the segmental
bronchi divide into
bronchioles, which
further subdivide and
supply the respiratory
surfaces.

32. Bronchopulmonary Segment
• There are ten
bronchopulmonary
segments in each
lung
• Eachbronchopulmonary
segment is shaped like an
irregular cone with the
apex at the origin of the
segmental bronchus and
the baseprojected
peripherally onto the
surface of thelung.

33. Bronchopulmonary Segment
• Abronchopulmonary
segment is the
smallest,functionally
independent region of a
lung and the smallest area
of lung that canbeisolated
and removed without
affecting adjacent regions.

37. Blood supply of thelung
• The bronchi and parenchymal tissue of
the lungs are supplied by bronchial
arteries a branches of the descending
thoracic aorta.
• Bronchial veins, which also
communicate with pulmonary veins,
drain into the azygos and hemiazygos.

40. Nerve supply of thelungs
• Apulmonary
plexusis located
at the root of
eachlung.
• Theplexus is
composed of
sympatheticfibres
(from the
sympathetic trunk)
and
parasympathetic
fibres (from the
vagus).