The document summarizes the anatomy of the lungs and related structures. It describes: - The lungs have two lobes separated by an oblique fissure. The left lung is smaller due to the heart protruding further left. - Structures pass through the hilum, including the pulmonary artery, veins, and bronchi. The right lung has three lobes separated by fissures. - The lungs are surrounded by pleura and indented by the heart and ribs. Segments are the functional units of the lungs supplied by their own bronchus, artery and vein.

1. Faarah abdilahi
AMOUD COLLEGE OF HEALTH
SCIENCE

2.  The two lungs are organs of respiration and
lie on either side of the mediastinum
surrounded by the right and left pleural
cavities. Air enters and leaves the lungs via
main bronchi, which are branches of the
trachea.

3.  The pulmonary arteries deliver deoxygenated
blood to the lungs from the right ventricle of
the heart. Oxygenated blood returns to the
left atrium via the pulmonary veins.

4.  The right lung is normally a little larger than
the left lung because the middle
mediastinum, containing the heart, bulges
more to the left than to the right.
 Each lung has a half-cone shape, with a base,
apex, two surfaces and three borders .

5. Each lung consists
:-
•Apex
•Base
•Costal or lateral
surface
•Mediastinal or
medial surface.

6.  The base sits on the diaphragm.
 The apex projects above rib I and into the root
of the neck.
 The two surfaces-the costal surface lies
immediately adjacent to the ribs and
intercostal spaces of the thoracic wall. The
mediastinal 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.

7.  The three borders-the inferior border of the
lung is sharp and separates the base from the
costal surface. The anterior and posterior
borders separate the costal surface from the
medial surface. Unlike the anterior and
inferior borders, which are sharp, the
posterior border is smooth and rounded.

8. Costal surface meet with the
mediastinal surface at anterior
border(sharp).
Has a rounded posterior
border(vertebral)
Costal & mediastinal surfaces end
below as the inferior border which
separates them from the base.
All surfaces are covered by pleura
except at the hilum.

9.  The lungs lie directly adjacent to, and are
indented by, structures contained in the
overlying area.
 The heart and major vessels form bulges in
the mediastinum that indent the medial
surfaces of the lung; the ribs indent the costal
surfaces.
 Pathology, such as tumors, or abnormalities
in one structure can affect the related
structure.

10.  Upper conical part lying above
the thoracic inlet.
 Covered by the Sibson’s fascia
 Extends up to the neck of 1st rib
behind, 3-4 cms above 1st costal
cartilage and 2.5 cms above
medial 1/3rd of clavicle.
 Covered on all sides by the
apical pleurae(parietal and
visceral).

11.  Anterior-Subclavian artery separated by
scalenus anterior from the subclavian vein.
 Posterior- Sympathetic chain,1st posterior
intercostal V,superior intercostal A and 1st
thoracic nerve (SVAN structures-medial to
lateral in front of neck of 1st rib)
 Medial-
 Brachiocephalic trunk , Rt brachiocephalic
V & trachea (Right apex)
 Left subclavian A;Lt brachiocephalic V &
esophagus + thoracic duct (Left apex)

12.  Could be injured in any stab wounds of the neck
or in surgical procedures like catheterization.
 Apex lung sounds are best heard with the
stethoscope over the medial end of the clavicle.
 Poor blood supply>>cause of TB lesions (nidus
for bacteria)

13.  Separated from the abdominal organs by the
diaphragm.
 Right lobe of liver on the right
 stomach, spleen & left lobe of liver on the left.

14.  Anterior border- from apex to
base

 Starts 2.5 cms above the
sternoclavicular joint  behind
sternal angle
 Extends behind body of sternum
till 4th costal cartilage (Both
lungs)
 On right side descends till
xiphisternal junction.
 On the left side deviates
laterally by 3.5 cms from midline
in 4th space descends till 6th
costal cartilage 4 cms from

16.  Cardiac notch – area where the anterior
margin and pleura deviate from midline on
the anterior border of left lung.
 pericardium is directly exposed to the chest
wall- Area of superficial cardiac dullness
 A route of entry for emergency intracardiac
administration of drugs
 For pericardiocentesis or
 a window to visualize the heart on an
echocardiography.

17.  Extends :-
• From 6th rib in the
midclavicular line (8th
for pleura)
• 8th rib in the mid axillary
line (10th for pleura)
• 10th rib in the posterior
axillary line (12th for
pleura).

18. • Rounded , extends from apex to base
• Separates the costal and mediastinal surfaces.
• Lies in the paravertebral gutter.

19.  Costal
 Covered by costal (parietal) and (visceral) pulmonary
pleura with pleural sac intervening.
 Has impressions created by the ribs.
 Mediastinal
 2 parts–
 vertebral part~~related to the thoracic vertebrae, IV
discs and structures in the paravertebral gutter.
 mediastinal part~~ covered by parietal & visceral
mediastinal pleurae EXCEPT at the hilum.
 Structures in the mediastinum leave impressions on
this surface in both lungs

23.  The root of each lung is a short tubular
collection of structures that together attach
the lung to structures in the mediastinum
 It is covered by a sleeve of mediastinal pleura
that reflects onto the surface of the lung as
visceral pleura.
 The region outlined by this pleural reflection
on the medial surface of the lung is the hilum,
where structures enter and leave

24.  A thin blade-like fold of pleura projects
inferiorly from the root of the lung and
extends from the hilum to the mediastinum.
This structure is the pulmonary ligament.
 It may stabilize the position of the inferior
lobe and may also accommodate the down-
and-up translocation of structures in the root
during breathing.

25.  In the mediastinum, the vagus nerves pass
immediately posterior to the roots of the lungs,
while the phrenic nerves pass immediately
anterior to them.
 Within each root and located in the hilum are:
 apulmonary artery;
 two pulmonary veins;
 a main bronchus;
 bronchial vessels;
 nerves; and
 lymphatics.

26.  Generally, the pulmonary artery is superior at
the hilum, the pulmonary veins are inferior,
and the bronchi are somewhat posterior in
position.
 On the right side, the lobar bronchus to the
superior lobe branches from the main
bronchus in the root, unlike on the left where
it branches within the lung itself, and is
superior to the pulmonary artery.

27. 1. Cardiac-
 Left ventricle
 Left auricle
 Infundibulum of
RV.
 2. Arch of aorta over
root.
 3. Descending
thoracic aorta
4. Esophageal- in front of
lower part of pulmonary
ligament
5. Apex-
•L Brachiocephalic V
•L Subclavian A
•Thoracic duct
•Esophagus.

28.  The right lung has three lobes and two
fissures .
 Normally, the lobes are freely movable
against each other because they are separated,
almost to the hilum, by invaginations of
visceral pleura.
 These invaginations form the fissures

29.  the oblique fissure separates the inferior lobe
(lower lobe) from the superior lobe and the
middle lobe of the right lung;
 the horizontal fissure separates the superior
lobe (upper lobe) from the middle lobe.

30.  The left lung is smaller than the right lung
and has two lobes separated by an oblique
fissure.
 The oblique fissure of the left lung is slightly
more oblique than the corresponding fissure
of the right lung.

31.  During quiet respiration, the approximate
position of the left oblique fissure can be
marked by a curved line on the thoracic wall
that begins between the spinous processes of
vertebrae TIII and TIV, crosses the fifth
interspace laterally, and follows the contour of
rib VI anteriorly .

32.  As with the right lung, the orientation of the
oblique fissure determines where to listen for
lung sounds from each lobe.
 The largest surface of the superior lobe is in
contact with the upper part of the
anterolateral wall, and the apex of this lobe
projects into the root of the neck. The costal
surface of the inferior lobe is in contact with
the posterior and inferior walls.

33.  When listening to lung sounds from each of the
lobes, the stethoscope should be placed on
those areas of the thoracic wall related to the
underlying positions of the lobes .
 The inferior portion of the medial surface of
the left lung, unlike the right lung, is notched
because of the heart's projection into the left
pleural cavity from the middle mediastinum.

34.  Both lungs have an oblique fissure.
 Starts about 6 cms below the apex on the
posterior border and extends downwards &
forwards to meet the anterior end of the base.

36.  a line drawn from the spinous process of T3,
around the side of the thorax to 6th rib in the
mid-clavicular line
 Along vertebral border of the scapula in a
hyperabducted arm

38.  Right lung has a horizontal fissure in addition.
• Extends from the middle of the anterior border to the
oblique fissure.
• Horizontal fissure divides right lung into 3 lobes:
 (Upper, middle & lower lobes)
 Left lung has only 2 lobes.(upper & lower)
 Lingula is a small part projecting from the lower part of
the cardiac notch

41.  The approximate position of the oblique fissure
on a patient, in quiet respiration, can be
marked by a curved line on the thoracic wall
that begins roughly at the spinous process of
vertebra TIV level of the spine, crosses the fifth
interspace laterally, and then follows the
contour of rib VI anteriorly .

42.  The horizontal fissure
follows the fourth
intercostal space from the
sternum until it meets the
oblique fissure as it crosses
rib V.
 The orientations of the
oblique and horizontal
fissures determine where
clinicians should listen for
lung sounds from each lobe.

43.  When listening to lung sounds from each of the
lobes, it is important to position the
stethoscope on those areas of the thoracic wall
related to the underlying positions of the lobes
.
 The medial surface of the right lung lies
adjacent to a number of important structures
in the mediastinum and the root of the neck .

44.  These include:--
 the heart,
 inferior vena cava,
 superior vena cava,
 azygos vein,
 esophagus.

46.  The hila of the lungs correspond to:
• anteriorly, the level of the 3rd-4th costal cartilage
• posteriorly, the level of the T5-T7 vertebrae
 One key difference between the hila is that:
• on the right, the right superior lobe bronchus
divides from the right principal bronchus before the
right hilum
• on the left side, the left principal bronchus does
not divide until it has entered the hilum of the lung

47.  B
 A
 B
 V
From above
downwards
1. Eparterial
bronchus
2. Pulmonary A
3. Hyparterial
bronchus
4. Lower pulmonary
vein
From before
backwards
1. Upper
pulmonary V
2. Pulmonary A
3. Bronchus(Hypart
erial)

48.  From above downwards
1. Pulmonary A
2. Bronchus
3. Lower pulmonary vein
From before
backwards
1. Upper
pulmonary V
2. Pulmonary A
3. Bronchus
A
B
V

50. Hyparterial
bronchus
Eparterial
bronchus

51. Primary
Secondary
Tertiary

52.  Definition:- The portion of lung aerated by
one tertiary (segmental) bronchus. It is a
self contained functionally independent
respiratory unit.
 Features:
• Subdivision of a lung lobe.
• Pyramidal in shape with the base directed
towards the surface.

53. • Surrounded by connective tissue.
• Contains a segmental bronchus, a
segmental pulmonary artery, lymph vessels
and autonomic nerves.
• Pulmonary Vein is intersegmental.
• A diseased unit can be removed surgically.

56.  Segments more liable to infection
• Apical segment of lower lobe being the most
dependent part on a supine position.
• Posterior segment of upper lobe- the arterial supply to
this segment is poor.
• Infection is usually restricted to one segment except in
tuberculosis and carcinoma.
• The right bronchus being wider and more straight
allows foreign bodies to enter with ease and reach the
middle lobe or lower lobe bronchi.

57.  Bronchial arteries supply the lung
tissue till the respiratory bronchioles.
 Left bronchial arteries –2 branches
from thoracic aorta
 Right bronchial artery from right 3rd
posterior intercostal artery.
 Bronchial veins are superficial and
deep

58.  Superficial
 Left bronchial veins-2 in number-
 upper drains into left superior intercostal
vein
 Lower drains into acessory hemiazygos V
 Right bronchial veins –2 in number-
Both drain into the azygos V
 Deep veins drain directly into the
pulmonary veins or left atrium.

59.  From superficial and deep.
 Superficial- subpleural (visceral)
bronchopulmonary at hilum.
 Deep travel along bronchi and pulmonary
vessels passing through pulmonary nodes
bronchopulmonary nodes at hilum
 All lymph leave hilum  tracheobronchial
nodes and then bronchomediastinal trunks.

62. Thank
you