Mellkasnyílás

Mellkasnyílás, also known as thoracic aperture, refers to the openings in the thoracic cage. There are two main thoracic apertures: the superior thoracic aperture and the inferior thoracic aperture. These openings are crucial for the passage of vital structures between the thoracic cavity and the neck or abdomen, respectively.

The superior thoracic aperture, also called the thoracic inlet, is a relatively small opening at the top of the thorax. It is bounded by the first thoracic vertebra posteriorly, the first pair of ribs laterally, and the manubrium of the sternum anteriorly. This aperture allows for the passage of the trachea, esophagus, subclavian arteries, subclavian veins, and various nerves and lymphatic vessels. The close proximity of these structures makes this area vulnerable to injury.

The inferior thoracic aperture, also known as the thoracic outlet, is significantly larger than the superior aperture. It is formed by the xiphoid process of the sternum anteriorly, the costal cartilages of the false ribs (ribs 8-10) laterally, the free ends of the 11th and 12th ribs laterally and posteriorly, and the 12th thoracic vertebra posteriorly. The diaphragm, a large muscular sheet, almost completely covers the inferior thoracic aperture, leaving only small openings for the esophagus, aorta, and the inferior vena cava to pass through into the abdomen. The size and shape of the thoracic apertures are important considerations in thoracic surgery and in understanding the biomechanics of respiration.