Faces of the Right Lower Lobe

The Two Lungs are Made up of Lobes
The post mortem specimen is viewed from the anterior aspect showing the upper lobes in red, the right middle lobe in pink and the lower lobes in green. 
Ashley Davidoff MD TheCommonVein.net 32558b02
Central Airways
This diagram shows the basic division of the tracheobronchial tree into lobes. The right lung is divided into right upper (RUL) (teal) right middle, (RML pink) and right lower lobe (RLL green). The left lung is divided into left upper (LUL teal), which includes the lingula(dark blue), and left lower lobe (LLL= green). Note that the two mainstem bronchi are of unequal length and size. The right mainstem is short and fat while the left is long and thin. This irregular dichotomous branching pattern is characteristic of the branching pattern of all the conducting systems within the lungs.
Ashley Davidoff
TheCommonVein.net 32686b05
Length of the bronchi
This diagram of the airways reveals the approximate lengths of the airways.  Note that the left main stem bronchus is about twice the length of the right whose length is truncated by the take off of the right upper lobe bronchus.
Courtesy Ashley Davidoff MD
TheCommonVein.net
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Anatomy of the Bronchial Segments of the Right and Left lobes of the Lung
Ashley Davidoff TheCommonvein.net 32686b05L segmental bronchi.8
ANATOMIC SPECIMEN SHOWING MAJOR and MINOR FISUSURES DIDING THE RIGHT LUNG INTO 3 LOBES
The right lung has a small right upper lobe (RUL) separated from the middle lobe (RML) by the minor fissure (pink,lower image) . Both the RUL and RML are anterior and are separated from the lower lober by the major fissure (orange line)
Ashley Davidoff MD
In the chest X-ray the overpenetrated technique allows us a view of the proximal airways. With the digital method and expanded gray scale of CT, we are able to reconstruct the data and create a much improved image of the bronchi. Not only do we see the right and left mainstem bronchi but we are also able to see the bronchi of the lobes, including the right upper, right lower lobe, and left lower lobe branches in this instance. In addition two of the three segmental bronchi of the right upper lobe are clearly resolved on this tomographic image.
Ashley Davidoff M.D.
TheCommonVein.net 32682
Fissures of the right lung
This coronal reformats through the tracheobronchial tree show the major fissures bilaterally.  They are usually quite difficult to see and unless you know where to look you may miss them altogether.  Usually there is a hint of hypovascularity along the fissure resulting in a relative lucency as can be appreciated in this examination.  The fissures have been overlaid in orange.  As the coronal cut proceeds posteriorly the lower lobe becomes more prominent and the upper lobes less so.  If you review the lateral chest x-ray and project the cuts you would get a better sense of this concept of the dominance of the RLL and its posterior location .
Ashley Davidoff MD.   TheCommonVein.net  32682b01.jpg
Right lung – shapes of the lobes
These images (left to right) show the  shapes of the RUL, RML and RLL. In Fig 1a and 1b the overlay represents the upper lobe.  Image 2a and 2b represent the middle lobe while in 3a and 3b the lower lobe is represented.  Note how the middle lobe hugs the right heart border and how much larger the RLL is compared to the RML and the RUL. 
Ashley Davidoff TheCommonVein.net 30398c01
Ashley Davidoff MD
LATERAL X-RAY SHOWING MAJOR and MINOR FISSURES DIVIDING THE RIGHT LUNG INTO 3 LOBES
The right lung has a relatively small right upper lobe (RUL) separated from the middle lobe (RML) by the minor fissure (pink,lower image). Both the RUL and RML are anterior and are separated from the lower lobe  by the major fissure (orange line)
Ashley Davidoff MD.   TheCommonVein.net  30398b06b
SEGMENTS OF THE LUNGS
The secondary lobules, connect, and unite, linked through the airways, blood vessels, lymphatics and nerves, to form segments in the lungs
There are ten bronchopulmonary segments in the right lung: three in the upper lobe, two in the middle lobe, and five in the lower lobe. Some of the segments may fuse in the left lung to form usually eight to nine segments (four to five in the upper lobe and four to five in the lower lobe.
Ashley Davidoff MD
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