The document summarizes the anatomy of the pleura and lungs. It describes the pleura as a membrane that surrounds the lungs and lines the chest cavity. It has a parietal layer on the chest wall and visceral layer covering the lungs. The two layers form a pleural cavity containing pleural fluid. Each lung is cone-shaped and divided into lobes separated by fissures. The lungs receive deoxygenated blood from the pulmonary arteries and return oxygenated blood to the heart via pulmonary veins. Lymph drains from the lungs through plexuses and nodes in the hilum. The lungs are innervated by the pulmonary plexus and have segments supplied by segmental bronchi, arteries and veins.

1. Anatomy of the pleura and lungs
Dr. Mohammed Mahmoud Mosaed

2. Chest Cavity
• The chest cavity is bounded by the chest
wall and below by the diaphragm.
• It extends upward into the root of the neck
about one fingerbreadth above the
clavicle on each side
• The chest cavity can be divided into a
median partition, called the mediastinum,
and the laterally placed pleurae and lungs

4. Pleura
• It is a serous membrane arranged as a closed invaginated
sac that covers the lung and lines the chest wall
• Each pleura has two parts:
• 1. Parietal layer (outer layer), which lines the thoracic
wall,
• 2. Visceral layer (inner layer), which completely covers
the outer surfaces of the lungs
• The two layers become continuous with one another by
means of a cuff of pleura at the hilum of each lung. the
pleural cuff hangs down as a loose fold called the
pulmonary ligament
• The parietal and visceral layers of pleura are separated
from one another by the pleural cavity (pleural space) that
contains a small amount of the pleural fluid

6. Division of the parietal pleura
• parietal pleura divided according to the region
in which it lies or the surface that it covers.
• The cervical pleura extends up into the neck.
It reaches a level 1 to 1.5 in. (2.5 to 4 cm)
above the medial third of the clavicle.
• The costal pleura lines the inner surfaces of
the ribs, the costal cartilages, the intercostal
spaces, the sides of the vertebral bodies, and
the back of the sternum

7. • The diaphragmatic pleura covers the
thoracic surface (upper surface) of the
diaphragm.
• The mediastinal pleura covers and
forms the lateral boundary of the
mediastinum. At the hilum of the lung, it is
reflected as a cuff around the vessels and
bronchi that constitute the lung root and
here becomes continuous with the visceral
pleura.

9. The pleural Recesses
• The costodiaphragmatic recesses are slitlike
spaces between the costal and diaphragmatic parietal
pleurae that are separated only by a layer of pleural
fluid. During inspiration, the lower margins of the lungs
descend into the recesses. During expiration, the
lower margins of the lungs ascend again.
• The costomediastinal recesses are situated along
the anterior margins of the pleura. They are slitlike
spaces between the costal and the mediastinal
parietal pleurae. During inspiration and expiration, the
anterior borders of the lungs slide in and out of the
recesses

11. Lines of pleural reflection
• The lines, which indicate the limits of the parietal pleura where it lies
close to the body surface, are referred to as the lines of pleural
reflection.
• The cervical pleura (dome of the pleura) bulges upward
into the neck A curved line may be drawn, convex upward, from the
sternoclavicular joint to a point 1 in. (2.5 cm) above the junction of the
medial and intermediate thirds of the clavicle
• The anterior border of the right pleura runs down behind
the sternoclavicular joint, almost reaching the midline behind the
sternal angle. It then continues downward until it reaches the
xiphisternal joint.
• The anterior border of the left pleura has a similar course,
but at the level of the fourth costal cartilage it deviates laterally and
extends to the lateral margin of the sternum to form the cardiac
notch. It then turns sharply downward to the xiphisternal joint.
• The lower border of the pleura on both sides follows a
curved line, which crosses the 8th rib in the midclavicular line and
the 10th rib in the midaxillary line, and reaches the 12th rib
adjacent to the vertebral column that is at the lateral border of the
erector spinae muscle

12. Dome of the pleura
2nd
costal cartilage
4th
costal cartilage
6th
costal cartilage
8th
rib in
midclavicular line
10th
rib in
midaxillary line
12th
rib

14. Nerve Supply of the Pleura
• The parietal pleura is sensitive to pain,
temperature, touch, and pressure and is supplied as
follows:
The costal pleura is segmentally supplied by the
intercostal nerves.
The mediastinal pleura is supplied by the phrenic nerve.
The diaphragmatic pleura is supplied over the domes by
the phrenic nerve and around the periphery by the
lower six intercostal nerves.
• The visceral pleura covering the lungs is sensitive
to stretch but is insensitive to common sensations
such as pain and touch. It receives an autonomic
nerve supply from the pulmonary plexus

15. lungs Anatomy of

16. Lungs
• The lungs are the essential organs of
respiration.
• They are situated on either side of the
heart and other mediastinal contents
• the lungs are soft, spongy and very
elastic.
• Each lung is conical in shape, covered
with visceral pleura, being attached to the
mediastinum only by its root
• In the child, they are pink, but with age,
they become dark and mottled

18. Anatomical features of the lungs
• Each lung has an apex, base, three borders and two surfaces
• Apex each lung has a blunt apex, which projects upward into the neck
for about 1 in. (2.5 cm) above the clavicle;
• Base is concave, and rests upon the upper surface of the diaphragm ;
• The costal surface is smooth and convex which corresponds to the
concave chest wall;
• The medial surface has a posterior vertebral part and anterior
mediastinal part.
The vertebral part lies in contact with the sides of the thoracic vertebrae
and intervertebral discs
The mediastinal part is deeply concave, and related to the mediastinal
content which causes impressions on this surface. The hilum, where
various structures enter or leave the lung lies on this surface
• The anterior border is thin and overlaps the heart; it is here on the left
lung that the cardiac notch is found.
• The posterior border is thick and lies beside the vertebral column.
• Inferior border

21. The mediastinal part of the medial
surface
• The mediastinal part is deeply
concave, and related to the
mediastinal content which causes
impressions on this surface.
• Also it contains the hilum, where
various structures enter or leave the
lung lies on this surface

23. Impressions on medial surface
of the right lung
1.The cardiac impression is related to the right atrium.
2. The impression for the superior vena cava and the
end of the right brachiocephalic vein ascends anterior
to the hilum.
3. The impression for azygos vein arches forwards
above the hilum forming deep sulcus,.
4. Oesophageal impression: The right side of the
oesophagus makes a shallow vertical groove behind
the hilum and the pulmonary ligament.
5. Groove for the inferior vena cava: lies
posteroinferior to the cardiac impression.
6. Groove for the trachea and right vagus nerve:
Between the apex and the groove for the azygos,.

25. Impressions on medial surface
of the left lung
• 1. The cardiac impression is related to left ventricle
• 2. Impression ascends in front of the hilum to
accommodate the pulmonary trunk.
• 3. Groove for the aortic arch and descending aorta: A
large groove arches over the hilum, and descends behind
it and the pulmonary ligament,
• 4. groove for the left subclavian artery: From the
summit of the aortic arch a narrower groove ascends to
the apex
• 5. The groove for thoracic duct and oesophagus lies
behind the groove for the left subclavian artery above the
aortic groove. Inferiorly, the oesophagus may mould the
surface in front of the lower end of the pulmonary ligament

27. Hilum of the lung
• The hilum is the part of the lung on its medial surface which
gives passage to the structures enters or leaves the lung (root
of the lung)
• The pulmonary root is formed by a group of structures
that enter or leave the hilum.
• These structures are:
• the principal bronchus, pulmonary artery, two pulmonary
veins, bronchial vessels, a pulmonary autonomic plexus,
lymph vessels, bronchopulmonary lymph nodes and loose
connective tissue.
• which are all enveloped by pleura. The pulmonary roots lie
opposite the bodies of the fifth to seventh thoracic vertebrae.
• The major structures in both roots are similarly arranged, so
that the upper of the two pulmonary veins is in front, the
pulmonary artery and principal bronchus are behind, and the
bronchial vessels are most posterior.

29. Lobes and fissures of right lung
Right Lung
• The right lung is divided by the oblique and
horizontal fissures into three lobes: the
upper, middle and lower lobes.
The oblique fissure runs from the inferior
border upward and backward across the
medial and costal surfaces until it cuts the
posterior border about 2.5 in. (6.25 cm)
below the apex.
The horizontal fissure runs horizontally
across the costal surface at the level of the
4th
costal cartilage to meet the oblique
fissure in the midaxillary line. The middle
lobe is thus a small triangular lobe
bounded by the horizontal and oblique
fissures.

30. Lobes and fissures of left lung
• Left Lung
• The left lung is divided by
oblique fissure into two
lobes: the upper and lower
lobes
• There is no horizontal fissure
in the left lung.

31. Bronchopulmonary Segments
• The bronchopulmonary segments are the
anatomic, functional, and surgical units of the
lungs.
• Each lobar (secondary) bronchus, which
passes to a lobe of the lung, gives off branches
called segmental (tertiary) bronchi.
• Each segmental bronchus passes to a
structurally and functionally independent unit of
a lung lobe called a bronchopulmonary
segment, which is surrounded by connective
tissue.

34. Structure of bronchopulmonary segment
• Main bronchus lobar bronchus
segmental bronchus
• Each segmental bronchus divides repeatedly.The
smallest bronchi divide and give rise to bronchioles,
The bronchioles then divide and give rise to terminal
bronchioles, which show delicate outpouchings from
their walls (respiratory bronchiole). The respiratory
bronchioles end by branching into alveolar ducts,
which lead into alveolar sacs.
• Each alveolus is surrounded by a rich network of
blood capillaries.

36. The main characteristics of a
bronchopulmonary segment
• It is a subdivision of a lung lobe.
• It is pyramid shaped, with its apex toward the lung
root.
• It is surrounded by connective tissue.
• It has a segmental bronchus, a segmental artery,
lymph vessels, and autonomic nerves.
• The segmental vein lies in the connective tissue
between adjacent bronchopulmonary segments.
• Because it is a structural unit, a diseased segment can
be removed surgically.

37. The main bronchopulmonary segments
Right lung
• Superior lobe:
1. Apical,
2. posterior,
3. anterior
Middle lobe:
4. Lateral,
5. medial
• Inferior lobe:
6. Superior (apical),
7. medial basal,
8. anterior basal,
9. lateral basal,
10.posterior basal
Left lung
•Superior lobe:
1. Apical,
2. posterior,
3. anterior,
4. superior lingular,
5. inferior lingular
• Inferior lobe:
6. Superior (apical),
7.medial basal,
8. anterior basal,
9.lateral basal,
10. posterior basal

41. Blood Supply of the Lungs
• The bronchi, the connective tissue of the lung,
and the visceral pleura receive their blood
supply from the bronchial arteries, which are
branches of the descending aorta.
• The bronchial veins drain into the azygos and
hemiazygos veins.
• The alveoli receive deoxygenated blood from
the terminal branches of the pulmonary
arteries. The oxygenated blood leaving the
alveolar capillaries drains into the tributaries of
the pulmonary veins, to empty into the left
atrium of the heart.

42. Lymph Drainage of the Lungs
• The lymph vessels originate in superficial and deep
plexuses.
• The superficial (subpleural) plexus lies beneath the
visceral pleura and drains over the surface of the lung
toward the hilum, where the lymph vessels enter the
bronchopulmonary nodes.
• The deep plexus travels along the bronchi and
pulmonary vessels toward the hilum of the lung,
passing through pulmonary nodes located within the
lung substance; the lymph then enters the
bronchopulmonary nodes in the hilum of the lung.
• All the lymph from the lung leaves the hilum and
drains into the tracheobronchial nodes and then into
the bronchomediastinal lymph trunks

44. Nerve Supply of the Lungs
• At the root of each lung is a pulmonary plexus
composed of efferent and afferent autonomic nerve
fibers.
• The plexus is formed from branches of the
sympathetic trunk and receives parasympathetic fibers
from the vagus nerve.
• The sympathetic efferent fibers produce
bronchodilatation and vasoconstriction.
• The parasympathetic efferent fibers produce
bronchoconstriction, vasodilatation, and increased
glandular secretion.
• Afferent impulses derived from the bronchial mucous
membrane and from stretch receptors in the alveolar
walls pass to the central nervous system in both
sympathetic and parasympathetic nerves.

45. Surface anatomy of the lungs
• The apex bulges upward into the neck A curved line may be drawn,
convex upward, from the sternoclavicular joint to a point 1 in. (2.5 cm)
above the junction of the medial and intermediate thirds of the
clavicle
• The anterior border of the right lung runs down behind the
sternoclavicular joint, almost reaching the midline behind the sternal
angle. It then continues downward until it reaches the xiphisternal
joint ) 6th
costal cartilage)
• The anterior border of the left lung has a similar course, but
at the level of the fourth costal cartilage it deviates laterally and
extends to the lateral margin of the sternum to form the cardiac
notch. It then turns sharply downward to the xiphisternal joint.
• The lower border of the pleura on both sides follows a
curved line, which crosses the 6th
rib in the midclavicular line and the
8th
rib in the midaxillary line, and reaches the 10th
rib adjacent to the
vertebral column that is, at the lateral border of the erector spinae
muscle