The lung apices are the uppermost regions of the lungs, extending into the root of the neck. Understanding them requires recognizing their physical location and unique characteristics. This knowledge helps in appreciating their role in both normal breathing and various health conditions.
Anatomical Placement
The lung apices are the rounded, blunt superior ends of each lung. These structures project upwards, extending beyond the first rib and the clavicle. Specifically, they can reach approximately 2.5 to 4 centimeters above the sternal end of the first rib, entering the lower part of the neck.
Each apex is covered by a dome-shaped extension of the pleura, known as the cervical pleura or cupula. This allows the lung tissue to fit snugly into the thoracic inlet, a narrow opening at the top of the chest cavity. The apices lie in close proximity to several important structures in the neck, including the subclavian artery and vein, and components of the brachial plexus, a network of nerves. The overall shape of the lungs is roughly conical, with the apices forming the pointed top.
Clinical Importance
The unique anatomical position and physiological characteristics of the lung apices contribute to their significance in clinical medicine. Their location makes them susceptible to certain diseases and influences how these conditions are detected and diagnosed. Pathologies preferentially affecting the upper lung zones often relate to differences in ventilation and perfusion compared to lower lung regions.
One condition prominently affecting the lung apices is tuberculosis. The Mycobacterium tuberculosis bacteria, responsible for this infection, thrives in environments with high oxygen tension. The upper lobes and apices of the lungs naturally have a higher ventilation-perfusion ratio, leading to a greater partial pressure of oxygen, thus creating a favorable environment for the bacteria’s growth. Tuberculosis can lead to the formation of granulomas and cavities within the lung tissue, often observed in these apical regions.
Certain types of pneumonia, particularly atypical pneumonia, can also show a predilection for the upper lobes, though they may present with more diffuse patterns than the consolidated appearance of typical bacterial pneumonia. Other conditions that can impact the lung apices include Pancoast tumors, which arise in this area and can affect nearby nerves and vessels due to the confined space. Sarcoidosis, emphysema, interstitial lung disease, and pneumothorax are additional examples of conditions that may involve or manifest in the lung apices.
Given their position, the lung apices can be obscured by overlying bony structures like the clavicles and ribs on standard chest X-rays. For this reason, specialized imaging techniques, such as apical lordotic views, are often employed to provide a clearer visualization of these areas. This enhanced imaging helps clinicians detect subtle changes, such as small masses, infiltrates, or scarring, which might otherwise be missed, assisting in the diagnosis and monitoring of various lung diseases.