What is directly behind the sternum, a term often referred to as the “posterior mediastinum,” is a region of the chest that is rich in anatomical structures and functions. This area, located between the lungs and the vertebral column, is a critical space in human physiology. Understanding its composition and the role it plays in the body is essential for medical professionals and those interested in human anatomy.
The posterior mediastinum is a triangular space that extends from the superior border of the fourth thoracic vertebra to the inferior border of the second rib. It is divided into two parts by the mediastinal pleura: the superior part is the posterior mediastinum, and the inferior part is the superior mediastinum. The space is enclosed by the pericardium anteriorly, the vertebral column posteriorly, the diaphragm inferiorly, and the lungs laterally.
Within this area, several vital structures are found. The most prominent of these is the heart, which is positioned in the middle of the posterior mediastinum. Surrounding the heart are the great vessels, including the aorta, pulmonary trunk, and inferior vena cava. These vessels play a crucial role in the circulation of blood throughout the body.
Additionally, the posterior mediastinum houses the phrenic nerves, which originate from the cervical spine and innervate the diaphragm. The sympathetic chain, responsible for the body’s “fight or flight” response, also runs through this region. The vagus nerve, which regulates many bodily functions, passes through the posterior mediastinum as well.
Another significant structure found behind the sternum is the thymus gland, an organ that plays a crucial role in the development of the immune system. The thymus gland is particularly important during childhood and adolescence, as it produces T-cells that are essential for the body’s defense against infections.
Understanding the anatomy of the posterior mediastinum is crucial for medical professionals, as diseases and conditions can arise from various structures within this region. For example, tumors, infections, and congenital abnormalities can occur in the heart, great vessels, thymus gland, and other structures found here.
In conclusion, what is directly behind the sternum is a complex and vital area of the body. Its anatomical structures and functions are integral to the overall health and well-being of individuals. As such, a comprehensive understanding of the posterior mediastinum is essential for medical professionals and anyone interested in human anatomy.
