In the previous section we’ve learned about the regions comprising the trunk, three of which were the thorax, abdomen, and pelvis. Let’s discuss each one very briefly. You’ve probably heard the expression ‘my heart is beating out of my chest’. However, what is the chest? In the world of anatomy, the chest is called the thorax and it is located between the neck and the abdomen. This region can be considered the epicentre of the circulatory system and the primary player in breathing, the latter function being mainly controlled by the diaphragm. The thoracic wall protects the internal contents and also supports the breasts.
The thorax is as complex on the inside as it is on the outside. Internally it consists of the thoracic cavity that, first and foremost, houses the lungs. These two vital organs are enveloped by membranes called the pleura and they are responsible for breathing. Altogether, the lungs occupy a surface area equivalent to the size of a tennis court. Sandwiched between the lungs is the mediastinum, a space that contains blood vessels, nerves, lymphatics, and most importantly, the heart. This vital organ is enclosed inside a sac called the pericardium and pumps 5 liters of blood every minute of your waking day through the entire body.