Lungs Anatomy

Lungs

• Lungs are essential organ of respiration.
• Shape of lungs are like half-cone.
• Lungs has an Apex & Base and 2 Surfaces and 3 Borders.
• Two lungs are present in every human body.

The trachea and lungs as seen from the front

Base - 

• It is deeply concave and faces downwards.
• It rest over the dom of diaphragm.

Apex - 

• It is conical & directed upwards, towards the root of the neck.

Borders (3) -

Anterior Border

• It is sharp and related to the anterior thoracic wall.
• It's lower part has deep concavity of the left side which is called as cardiac notch.

Posterior Border

• It is rounded & found the junction of costal and medial surface.
• It corresponds with the head of the ribs.

Inferior Border

• It is convex and sharp, it faces downwards.

Surfaces (2) -

Costal Surface

• This surface is related to rib cage & sternum.

Medial Surface

It is divided into two parts...

1. Vertibral part - it is the posterior part of the medial surface and related to the vertibral bodies.

2. Mediastnal part - this surface is marked by hilum ( Hilum - it is depression from which structure enters or exit from here).

It is the large anterior part of the medial surface which is related to the mediastinum.

Side Determination -

• Sharp anterior border faces forward.
• Deep concave faces inferiorly.
• Surface having hilum faces medially.

Right Lung - 

• It has 2 fissures (Oblique, Transverse).
• It has 3 lobes ( Superior, Middle and Inferior).

Impression on the mediastinal surface of right lung

Left Lung -

• It has only one fissure ( Oblique).
• It has 2 lobes (Superior and Inferior).
• The lower part of superior lobe is also called as lingula, which correspond with middle lobe of the right lung.

Impression on the mediastinal surface of left lung

Difference between Right and Left Lung...

                   Right Lung                       Left Lung

1. Weight-  625gm                    -  565gm

2. Size -      Shorter & broader- longer & narrower

3. Fissure- Two                          -  one

4. Lobes -   Three                       - Two

5. Lingula - absent                    - present 

6. Cardiac notch - absent         - present 

7. BPS -      10                              - 8

Broncho pulmonary segments (BPS) 

• It is difine as the developmental structural and functional unit of the lungs.
• It consists of tersory bronchus and lungs tissue.

Right lung (10 - BPS)

• Superior lobe has 3 BPS
• Middle lobe has 2 BPS
• Inferior lobe has 5 BPS

Left lung ( 8 - BPS)

• Superior lobe has 3 BPS
• Inferior lobe has 5 BPS

Bronchiopulmonary segments

Arterial Supply of Lungs

1. Pulmonary Arteries - one on each side ( Right and Left lungs).

2. Bronchial Arteries - one for right lung and two for left lung.

Venous drainage 

1. Pulmonary vein - two from right and two from left lungs (a superior and a inferior).

2. Bronchial vein - one from each lung.

Lymphatic drainage 

1. Pulmonary limph node.

2. Hilar limph node.

3. Trachiobronchial limph node.

4. Paratrachial limph node.

Nerve Supply 

• Sympathetic - anterior and posterior pulmonary plexus.
• Parasympathetic - vagus nerve.

Applied 

1. Pneumonectomy - removal of whole lung.

2. Lobectomy - removal of lobe.

3. Segmental resection - removal of BPS.