anatomy of lungs bd chorshiya medical MBBS

1. Anatomy of Lungs

2. Introduction
lungs or pulmones: Principal organs of
respiration.
Functions :
 Breathing
 Exchange of gases
 MaintainAcid base balance
 Excretion
Location:
 Thoracic cavity
 Separated by mediastinum
Texture: Spongy
Color:
 Child: Pink
 Young: Brown to grey
 Gradually  Mottled black : Carbon particles
Weight: Right lung( 625g) heavier than left (575g)

3. External Features of lungs
1. Apex
2. Base
3. Borders:A|P | I
4. Surfaces :
1. Costal
2. Medial
1. Vertebral
2. Mediastinal
5. Fissures & Lobes
6. Roots
 Apex 1
 Base 1
 Surfaces 2
 Borders 3
 Fissures 2(R)+1(L)
 Lobes 3(R)+2(L)

5. 1.Apex/Cupola : Rounded/blunt superior end of the lung.
Relations
Anterior:
(a)Subclavian artery
(b) internal thoracic artery,
(c) Scalenus anterior
Posterior:
(a) ventral ramus of first thoracic nerve
(b) first posterior intercostal artery
(c) first posterior intercostal vein
(d) sympathetic chain
C/a : Pancoast syndrome :
 Involvement of structures related to the posterior aspect of the apex of
lung

6. 2. Base/diaphragmatic surface:
 Semilunar & Concave
 Rests on dome of the diaphragm
3. Surfaces:
1. Costal surface: Convex and large:
2. Medial:
 Vertebral part: Posterior
 Mediastinal part:Anterior
4. Borders:
1.Anterior border:
Very thin
Left lung:
Cardiac notch
Below the cardiac notch- a tongue- shaped projection
called lingula
2. Posterior border:
Thick & Poorly defined (C7-C10)
3. Inferior Border:
Between costal and medial surfaces

7. Fissures & Lobes
Right Lung Left lung
Fissures:
1. Oblique
2. Horizontal
Fissures:
1. Oblique
Lobes:
1. Superior
2. Middle
3. Inferior
Lobes:
1. Superior
2. Inferior

8. Root
 The root of lung is a collection of structures connecting the medial surface of the lung with the
mediastinum.

9. BRONCHIAL TREE
The bronchial tree consists of principal bronchus, lobar
bronchi, terminal bronchioles, and respiratory bronchioles.

10. Right Lung Left Lung
Principal bronchus Shorter, wider, and more
vertical.
1 inch (2.5 cm) long .
Long axis:About 25° deviates
from trachea
Longer, Narrower, and
more horizontal than the
right.
2 inches (5 cm) long.
Long axis:About 45° deviates
from trachea
LOBAR BRONCHI On entering the lung, the right
principal bronchus divides
(gives off) three lobar bronchi,
one for each lobe of the right
lung.
The left principal bronchus on
entering the lung divides into
two lobar bronchi, one for each
lobe of the left lung.
TERTIARY (SEGMENTAL) BRONCHI
Each lobar bronchus divides into segmental (tertiary) bronchi,
one for each bronchopulmonary segment.
The segmental bronchi divide repeatedly to form very small
bronchi called terminal bronchioles.
The terminal bronchioles give off respiratory bronchioles,
which lack cartilage in their walls.

12. Each respiratory bronchiole aerates a small portion of
lung called pulmonary units,which is concerned with
gaseous exchange within the lung.