lungs anatomy and pleural cavity

2. Group b

3. LUNGS
The lungs lie either side of
the mediastinum, within the
thoracic cavity. Each lung is
surrounded by a pleural
cavity, which is formed by
the visceral and parietal
pleura

4. Lungs gross anatomy
• Lungs are pair of respiratory organs situated in thoraic cavity
• Right and left lung are separated by the mediastinum
 Weight
Left 550
Right 600
 Texture
Spongy
 Colour
yellow brown
Adults mottled black due to
deposition of carbon particles

5. Lung gross Structure

6. Apex – The blunt superior end of the lung. It projects
upwards, above the level of the 1st rib and into the floor
of the neck.
Base – The inferior surface of the lung, which sits on the
diaphragm.
Lobes (two or three) – These are separated by fissures
within the lung.
Surfaces (three) – These correspond to the area of the
thorax that they face. They are named costal,
mediastinal and diaphragmatic.
Borders (three) – The edges of the lungs, named the
anterior, inferior and posterior borders.

7. Lobes
• The right and left lungs do not have an identical lobular structure.
• The right lung has three lobes; superior, middle and inferior. The lobes are divided from each other by
two fissures:
 Oblique fissure
Runs from the inferior border of the lung in a superoposterior direction, until it meets the
posterior lung border. start from 5tv and end at 6th costochondral junction
 Horizontal fissure
Runs horizontally from the sternum, at the level of the 4th rib, to meet the oblique fissure.4th costal
cartilage to meet oblique fissure
The left lung contains superior and inferior lobes, which are separated by a similar oblique fissure.

9. Surfaces of lungs
• are three lung surfaces, each corresponding to an area of the thorax
 mediastinal surface
The mediastinal surface of the lung faces the lateral aspect of the middle mediastinum.
The lung hilum (where structures enter and leave the lung) is located on this surface
 diaphragmatic surface
The base of the lung is formed by the diaphragmatic surface. It rests on the dome of the
diaphragm, and has a concave shape. This concavity is deeper in the right lung, due to the
higher position of the right dome overlying the liver.
 costal surface
The costal surface is smooth and convex. It faces the internal surface of the chest wall. It is
related to the costal pleura, which separates it from the ribs and innermost intercostal
muscles.

10. Borders
anterior border
The anterior border of the lung is formed by the convergence of the mediastinal and
costal surfaces. On the left lung, the anterior border is marked by a deep notch,
created by the apex of the heart. It is known as the cardiac notch.
inferior border
The inferior border separates the base of the lung from the costal and mediastinal
surfaces.
 posterior border
The posterior border is smooth and rounded (in contrast to the anterior and inferior
borders, which are sharp). It is formed by the costal and mediastinal surfaces meeting
posteriorly.

11. The lower border of every lung is 2 – rib spaces higher than the lower border of the pleura.
Therefore, it is located along the line, which cuts.
A. 6th rib in the midclavicular line,.
B. 8th rib in the midaxillary line, and.
C. 10th rib at the lateral border of erector spinae and ends 2 cm lateral to the spine of T10
vertebra
Lower Border

12. Anterior Border
• The anterior border of the left lung has a distinctive notch (the cardiac notch), which
enters laterally behind the 4th and 5th intercostal spaces.

13. Posterior Border
• Its lower end ends at the level of spine of T10 vertebra.

14. ROOT AND HILUM
The lung root is a collection of
structures that suspends the
lung from the mediastinum.
Each root contains a bronchus,
pulmonary artery, two
pulmonary veins, bronchial
vessels, pulmonary plexus of
nerves and lymphatic vessels.
All these structures enter or
leave the lung via the hilum –
a wedge shaped area on its
mediastinal surface.

15. Tracheobronchial tree
• Each Segmental bronchus passes to a structurally and functionally independent
unit of lung lobe called as Broncho Pulmonary Segment.
• These are well defined Anatomic, Functional and surgical units of lungs

16. Alveolar sacs
Alveolar ducts
Respiratory bronchioles
Conductory bronchioles
Tertiary bronchi
Secondary bronchi
Trachea

17. Right main
bronchus
Segmental
bronchus
Right
lower
lobar
bronchus

20. Right lung Left lung
1 Apical segment
2 Posterior segment
3 Anterior segment
4.Lateral segment
5.Medial segment
1+2 apicoposterior
Segment
3 anterior segment
4.superior lingular segment
5.inferior lingular segment
6.Superior segment
7.Medial basal segment
8.Anterior basal segment
9.Lateral basal segment
10.Posterior basal segment
6.Superior segment
7.Absent
8.Anteromedial basal segments
9.Lateral basal segment
10.Posterior basal segment
Upper lobe
bronchus
Medial lobe
bronchus
Lower
lobe
bronch
us
Superior
division
Inferior
division
Upper lobe
bronchus
Lower lobe
bronchus

22. Airway Progression
 Trachea
16-20 C- shaped hyaline cartilage rings Bifurcates at the level of sternal angle.
 Carina
Ridge on internal aspect of last cartilage. Point where trachea branches.
 Left main bronchus
Longer(5 cm),smaller diameter, more horizontal, makes an angle of 45o with trachea. Gives 2 lobar bronchi
 Right main bronchus
Shorter(2.5cm), larger diameter, more vertical( 45o ), more susceptible to aspiration. Gives 3 lobar
bronchi.
Each main or primary bronchus runs into the hilus of lung posterior to pulmonary vessels

23. Airway Progression
Segmental brochi broke into sub segmental bronchus

24. Airway Progression
• Respiratory Bronchiols: 2 or more
branches from each terminal
bronchioles with air sac buds. This is
first level of gas exchange.
• Respiratory bronchioles end in
alveoli.
• Pores of khan & channels of Lambert
are present to connect two alveoli

25. Vasculature
The lungs are supplied with deoxygenated blood by
the paired pulmonary arteries. Once the blood has
received oxygenation, it leaves the lungs via
four pulmonary veins (two for each lung).
The bronchi, lung roots, visceral pleura and
supporting lung tissues require an extra nutritive
blood supply. This is delivered by the bronchial
arteries, which arise from the descending aorta.
The bronchial veins provide venous drainage. The
right bronchial vein drains into the azygos vein,
whilst the left drains into the accessory hemiazygos
vein.

26. Nerve Supply
The nerves of the lungs are derived from the pulmonary plexuses.
They feature sympathetic, parasympathetic and visceral afferent
fibres:
Parasympathetic: Derived from the vagus nerve. They stimulate
secretion from the bronchial glands, contraction of the bronchial
smooth muscle, and vasodilation of the pulmonary vessels.
Sympathetic: Derived from the sympathetic trunks. They
stimulate relaxation of the bronchial smooth muscle, and
vasoconstriction of the pulmonary vessels.
Visceral afferent: Conduct pain impulses to the sensory ganglion
of the vagus nerve

27. Characteristic Features of BPS
• Largest subdivision of lung lobe.
• Pyramidal in shape with apex towards the root of hilum.
• Each segment is an independent respiratory unit.
• Each segment has its own separate artery [branches of pulmonary artery],segmental
bronchus, autonomic nerves & lymph vessels

28. Conductory zone
The conducting zone of the respiratory system is made up of the following
1. Nose
2. Pharynx
3. Larynx
4. Trachea
5. Bronchi
6. Bronchioles
7. Terminal bronchioles

29. Trachea
Course
the trachea commences at the level of the cricoid cartilage in
the neck (C6). It terminates at the level of the angle of Louis (T4/5)
where it bifurcates into right and left main bronchi
Structure
the trachea is a rigid fibroelastic structure. Incomplete
rings of hyaline cartilage continuously maintain the patency of
the lumen. The trachea is lined internally with ciliated columnar
epithelium.

30. Relations
behind the trachea lies the oesophagus. The 2nd, 3rd and
4th tracheal rings are crossed anteriorly by the thyroid isthmus
Blood supply
the trachea receives its blood supply from branches of
the inferior thyroid and bronchial arteries

31. Functions
Low resistance pathway for airflow
Defense
Warms and moistens air
Filters air
Phonates (vocalize sounds)

32. Respiratory zone
• The respiratory zone is the site of O2 and CO2 exchange with the blood
• The respiratory bronchioles and the alveolar ducts are responsible for 10% of the gas
exchange.The alveoli are responsible for the other 90%.
• The respiratory zone represents the 16th through the 23rd division of the
respiratory tract.

33. Pleura
The pleurae and lungs lie
on either side of the
mediastinum within the
chest cavity

34. Pleura
Each lung is enclosed in a serous pleural sac
Serous membrane lined by flattened epithelium
(mesothelium)
 Outer layer
Parietal pleura
 Inner layer
Visceral pleura (Pulmonary pleura)
 Pleural cavity
potential space in between two layers
consists of serous pleural fluid, which lubricate pleural
surfaces

35. visceral pleura
Pulmonary pleura
Adherent to all surfaces including
those in fissures
Except the root or hilum of the lung
Visceral pleura is continuous with
parietal pleura at the hilum of the lung

36. Parietal pleura
• Outer layer of the pleura
• Lines the corresponding half of the thoracic wall, mediastinum and diaphragm
• It is divided into four parts
Cervical pleura
lies over the apex of the lungs
Costal pleura
covers the internal surface of the thoracic wall
Mediastinal pleura
covers the lateral aspect of the mediastinum
Diaphragmatic pleura
lies on the thoracic surface of the diaphragm

37.  EMPYEMA collection of pus in pleural cavity without air
 COMPRESSION OF THE TRACHEA bilateral enlargement of thyroid gland
 AORTIC ARCH ANERYSM dilation of aortic arch
 TRACHEITIS OR BRONCHITIS give rise to a raw burning sensation felt
deep to the sternum instead of actual pain
 INHALED FOREIGN BODIES common in children, tend to enter right
bronchus instead of left because the right bronchus is wider & more direct
continuation of the trachea
 BRONCHOSCOPY examination of interior of trachea through bronchoscope
 TRACHEOSTOMY cutting the trachea
Clinical Notes

38. Which of the following structures separates the
lung into lobes
A. ?
B. mediastinum
C. fissure
D. root
E. pleura

39. A section of the lung that receives its own tertiary bronchus is called
the ________.
A. bronchopulmonary segment
B. pulmonary lobule
C. interpulmonary segment
D. respiratory segment

40. The ________ circulation picks up oxygen for cellular use and drops off
carbon dioxide for removal from the body.
A. pulmonary
B. interlobular
C. respiratory
D. bronchial

41. What does structure R relate to?
A. Groove for azygos vein
B. Oblique fissure
C. Groove for arch of aorta
D. Diaphragmatic surface

42. The apex of the lungs is covered by:
A. Cervical pleura
B. Diaphragmatic pleura
C. Mediastinal pleura
D. Costal pleura

43. Which of the following vessels supplies the lungs themselves with
oxygen?
A. Bronchial artery
B. Bronchial vein
C. Pulmonary artery
D. Pulmonary vein

44. The walls between neighbouring alveoli are known
as:
A. Alveolar septa
B. Alveolar ducts
C. Alveolar epithelia
D. Alveolar sacs

45. A 'stony dull' sound on percussion is typically suggestive of:
A. Pleural effusion
B. Fibrosis
C. Emphysema
D. Pneumothorax

46. The lungs and visceral pleura receive
parasympathetic innervation from
A. the vagus nerve
B. cranial nerve IX
C. spinal nerve II
D. the phrenic nerve

47. The pleura that surrounds the lungs consists of
two layers, the ________.
A. visceral and parietal pleurae.
B. mediastinum and parietal pleurae.
C. visceral and mediastinum pleurae.
D. none of the above

48. • A 36-year-old man was taken to the emergency department after having been found
lying unresponsive in a local park with an empty whisky bottle nearby. He was
given oxygen by an open face mask during the 15-minute ride in the ambulance. The
paramedic decided to improve the airway by passing a soft nasal tube. On
attempting to pass the well-lubricated tube into the patient’s nose, the paramedic
found it impossible to push it much beyond the nasal vestibule on either side.What
are the common anatomic causes of obstruction of the nasal airway?
Answers;
The most common cause for difficulty in passing a
nasal tube is a deflected nasal septum. This occurs
more commonly in the male, and is thought to be due
to previous trauma to the septum during the period of
active growth. Nasal spurs and polyps may cause difficulty
and swelling of the mucous membrane secondary
to infection or chemical irritation, and can also cause
blockage. The widest part of the nasal cavity is near
the floor.

49. Because of the rapid increase in the size of the tumor,
the following lymph nodes were examined for metastases:
A. Superficial inguinal nodes
B. Anterior axillary nodes
C. Posterior axillary nodes
D. External iliac nodes
E. Deep cervical nodes

50. BIBILIOGRAPHY
ESSIENTIALS OF ANATOMY AND PHYSIOLOGY BY STEPHENS
ROSS AND WILSON ANATOMY AND PHYSIOLOGY
LASTs ANATOMY BY R.M.H MEMINN
 GREY ANATOMY