Lungs Anatomy | Shapes and Surfaces of the Lungs

Author: Scott A. Sheffield MS

Last update:

The two lungs are the primary organs of our respiratory system, each with characteristic shapes and surfaces.

Main characteristics of the lungs:

  • The soft, elastic lungs occupy most of the thoracic cavity and are protected from injury by the surrounding the image descriptionsternum and image descriptionrib cage.
  • Both right lung and left lung rest on the diaphragm muscle that separates the thoracic and abdominal cavities.
  • A large portion of each lung consists of image descriptionblood vessels (arteries, veins, & capillaries) and image descriptionrespiratory tubes (bronchi, bronchioles, & alveolar ducts).
  • Most of the lung volume, however, is made of small clusters of alveoli. Each image descriptionalveolus is a small, thin-walled, cup-shaped sac that protrudes from the smallest air ducts.
  • There are approximately 300 million alveoli in each lung, and they are the regions where gases are exchanged with nearby capillaries.
A view of the rib cage
A skeleton on an anterior view with the lungs illustrated inside the rib cage and the sternum bone labeled
A view of the rib cage and lungs with rib cage labeled
Blood vessels labeled
Respiratory tubes labeled
Capilarry veins and arteries reaching into the alveoles of the lung
Capilarry veins and arteries reaching into the alveoles of the lung
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  • Due to the elevated position of the image descriptionliver, the image descriptionright lung is slightly (= 5 cm) shorter than the image descriptionleft lung. The left lung, however, has less volume because some space is taken up by the heart.
  • Each lung is cone-shaped. The concave image descriptionbase rests on the diaphragm and the narrow image descriptionapex projects under the clavicle.
  • A double-walled, fluid-filled sac called the image descriptionpleura envelops each lung and aids in the ventilation process.
  • The anterior, lateral, and posterior lung surfaces lie adjacent to the ribs and are thus often referred to as the image descriptioncostal surface.
Anterior View of the Body
Liver labeled on anterior view of body demonstrating lungs anatomy and the surrounding structures
Right lung labeled on anterior view of body demonstrating lungs anatomy and the surrounding structures
Lived labeled on anterior view of body demonstrating lungs anatomy and the surrounding structures
Base labeled on anterior view of body demonstrating lungs anatomy and the surrounding structures
Apex of the lung in an illustration demonstrating lungs anatomy and the surrounding structures
Pleura labeled on anterior view of body
Costal Surface labeled on anterior view of body
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Mediastinal space and hilum:

  • Between the lungs is the image descriptionmediastinum. This large open space contains the heart, blood vessels, esophagus, nerves, trachea, and primary bronchi.
  • Along the image descriptionmediastinal surface of each lung is a depression called the image descriptionhilum (or hilus).
  • This is the region where the major blood vessels, bronchi, and nerves enter and leave the lung. Together, these structures form the root of the lung.
  • A prominent indentation called the image descriptioncardiac notch is also present along the mediastinal surface of the left lung. This indentation provides room for the apex of the heart.

 

Learn respiratory system anatomy fast and efficiently with quizzes and labeled diagrams.

Lungs and mediastinum
Lungs and mediastinum labeled
Mediastinal surface shown
Lungs, mediastinum, and hilum labeled
Lungs, mediastinum, and cardiac notch labeled
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An Overview of Lung Anatomy:

Lung Quiz: Shape and General Composition

Test yourself on the anterior view of the lungs.

image descriptionShow/image descriptionHide answers

Test yourself while observing the shapes and surfaces of the lungs.

An Overview of the Shapes and Surfaces of the Lungs:

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Test Yourself on Shapes and Surfaces of the Lungs with Answers Hidden
Test Yourself on Shapes and Surfaces of the Lungs with Answers Revealed
Test yourself on lung anatomy with answers hidden
Test yourself on lung anatomy with answers shown
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