The lungs facilitate the exchange of gases that sustains life. This article explores the uppermost portion of each lung, known as the apex, detailing its anatomical position and the reasons its location holds significant implications.
Understanding the Lung Apex
The lung apex represents the uppermost part of each lung. This region is distinctly rounded and conical, tapering to a point as it extends upwards. It stands in contrast to the broader, concave base of the lung, which rests upon the diaphragm.
Its Position in the Chest and Neck
The lung apex extends superiorly, projecting beyond the confines of the rib cage into the root of the neck. Specifically, it reaches approximately 2.5 to 4 centimeters above the level of the sternal end of the first rib. This upward projection places it in close proximity to the clavicle and the shallow depression known as the supraclavicular fossa.
This uppermost portion of the lung is enveloped by the cervical pleura or cupula, a specialized part of the double-layered membrane surrounding the lungs. This covering bulges through the superior thoracic aperture, providing an interface between the lung tissue and the structures of the lower neck. The close anatomical relationships in this area mean the apex lies near various nerves and blood vessels as they pass between the chest and the head and upper limbs.
Why the Apex’s Location is Important
The unique position of the lung apex makes it susceptible to certain injuries and medical conditions. Because it extends into the neck, it is vulnerable to trauma, including penetrating wounds to the neck or shoulder region.
The apex is also a common site for the development of specific lung conditions. Tuberculosis, for instance, often manifests initially in the apical regions. Additionally, a type of lung cancer known as a Pancoast tumor frequently originates in the apex. These tumors can grow to affect nearby structures, including nerves of the brachial plexus and major blood vessels like the subclavian artery and vein.
During a physical examination, listening to breath sounds over the lung apices provides important diagnostic clues. While normal breath sounds are generally softer here compared to other lung regions, changes in sound quality or presence can indicate underlying issues. The proximity of the apex to various neurovascular structures also means that issues originating in this lung region can present with symptoms seemingly unrelated to the lungs, such as arm pain or neurological changes.