Secondary bronchus

Template:Infobox Anatomy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

The Left lung is divided into two lobes, an upper and a lower, by the oblique fissure, which extends from the costal to the mediastinal surface of the lung both above and below the hilus.

As seen on the surface, this fissure begins on the mediastinal surface of the lung at the upper and posterior part of the hilus, and runs backward and upward to the posterior border, which it crosses at a point about 6 cm. below the apex.

It then extends downward and forward over the costal surface, and reaches the lower border a little behind its anterior extremity, and its further course can be followed upward and backward across the mediastinal surface as far as the lower part of the hilus.

The superior lobe lies above and in front of this fissure, and includes the apex, the anterior border, and a considerable part of the costal surface and the greater part of the mediastinal surface of the lung.

The inferior lobe, the larger of the two, is situated below and behind the fissure, and comprises almost the whole of the base, a large portion of the costal surface, and the greater part of the posterior border.

On the mediastinal surface, immediately above the hilus, is a well-marked curved furrow produced by the aortic arch, and running upward from this toward the apex is a groove accommodating the left subclavian artery; a slight impression in front of the latter and close to the margin of the lung lodges the left innominate vein.

Behind the hilus and pulmonary ligament is a vertical furrow produced by the descending aorta, and in front of this, near the base of the lung, the lower part of the esophagus causes a shallow impression.

• 
  diagram of the respiratory system
• 
  Anatomy of lungs.
• 
  Front view of heart and lungs.
• 
  Transverse section of thorax, showing relations of pulmonary artery.
• 
  The position and relation of the esophagus in the cervical region and in the posterior mediastinum. Seen from behind.
• 
  The thymus of a full-time fetus, exposed in situ.

• Lingula of left lung
• Right lung

• Template:Chorus
• Template:SUNYAnatomyFigs – “Mediastinal surface of the left lung.”
• Diagram and quiz at cancer.gov
• Slide at mgccc.cc.ms.us
• Template:RocheLexicon
• Template:GPnotebook – “lobes (left lung)”
• Diagram at md.chula.ac.th

Template:Gray’s Template:Lung

Template:WikiDoc Sources

Template:Infobox Anatomy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

The Right lung is divided into three lobes, superior, middle, and inferior, by two interlobular fissures:

• One of these, the oblique fissure, separates the inferior from the middle and superior lobes, and corresponds closely with the fissure in the left lung. Its direction is, however, more vertical, and it cuts the lower border about 7.5 cm. behind its anterior extremity.

• The other fissure, the horizontal fissure, separates the superior from the middle lobe. It begins in the previous fissure near the posterior border of the lung, and, running horizontally forward, cuts the anterior border on a level with the sternal end of the fourth costal cartilage; on the mediastinal surface it may be traced backward to the hilus.

The middle lobe, the smallest lobe of the right lung, is wedge-shaped, and includes the lower part of the anterior border and the anterior part of the base of the lung. (There is no middle lobe on the left lung, though there is a lingula.)

The superior and inferior lobes are similar to their counterparts on the left lung.

The right lung, although shorter by 2.5 cm. than the left, in consequence of the diaphragm rising higher on the right side to accommodate the liver, is broader, owing to the inclination of the heart to the left side; its total capacity is greater and it weighs more than the left lung.

On the mediastinal surface, immediately above the hilus, is an arched furrow which accommodates the azygos vein; while running upward, and then arching lateralward some little distance below the apex, is a wide groove for the superior vena cava and right innominate vein; behind this, and nearer the apex, is a furrow for the innominate artery.

Behind the hilus and the attachment of the pulmonary ligament is a vertical groove for the esophagus; this groove becomes less distinct below, owing to the inclination of the lower part of the esophagus to the left of the middle line.

In front and to the right of the lower part of the esophageal groove is a deep concavity for the extrapericardiac portion of the thoracic part of the inferior vena cava.

• 
  Anatomy of lungs.
• 
  Front view of heart and lungs.
• 
  Transverse section of thorax, showing relations of pulmonary artery.
• 
  The position and relation of the esophagus in the cervical region and in the posterior mediastinum. Seen from behind.
• 
  The thymus of a full-time fetus, exposed in situ.

• Left lung

• Lung Lobes
• Template:Chorus
• Template:SUNYAnatomyFigs – “Mediastinal surface of the right lung.”
• Diagram and quiz at cancer.gov
• Template:RocheLexicon
• Cross section at univie.ac.at

Template:Gray’s Template:Lung

nl:Rechter long

Template:WikiDoc Sources