Anatomy of lungs
Anatomy of Lungs
Ajay Dogra
Ajay Dogra
Introduction
lungs or pulmones: Principal organs of
respiration.
Functions :
Breathing
Exchange of gases
Maintain Acid 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)
External Features of lungs
1. Apex
2. Base
3. Borders: A|P | I
4. Surfaces :
1. Costal
2. Medial Apex 1
1. Vertebral
Base 1
2. Mediastinal
5. Fissures & Lobes Surfaces 2
6. Roots Borders 3
Fissures 2(R)+1(L)
Lobes 3(R)+2(L)
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
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
Fissures & Lobes
Right Lung Left lung
Fissures: Fissures:
1. Oblique 1. Oblique
2. Horizontal
Lobes: Lobes:
1. Superior 1. Superior
2. Middle 2. Inferior
3. Inferior
Root
The root of lung is a collection of structures connecting the medial surface of the lung with the
mediastinum.
BRONCHIAL TREE
The bronchial tree consists of principal bronchus, lobar
bronchi, terminal bronchioles, and respiratory bronchioles.
Right Lung Left Lung
Principal bronchus Shorter, wider, and more Longer, Narrower, and
vertical. more horizontal than the
1 inch (2.5 cm) long . right.
Long axis: About 25° deviates 2 inches (5 cm) long.
from trachea Long axis: About 45° deviates
from trachea
LOBAR BRONCHI On entering the lung, the right The left principal bronchus on
principal bronchus divides entering the lung divides into
(gives off) three lobar bronchi, two lobar bronchi, one for each
one for each lobe of the right lobe of the left lung.
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.
Each respiratory bronchiole aerates a small portion of
lung called pulmonary units, which is concerned with
gaseous exchange within the lung.
