Surface anatomy

The parietal pleura, and hence the pleural cavity, usually projects 3 cm above the medial aspect of the first rib inferiorly to the thoracic surface of the diaphragm. It lines the inside of the thoracic cage. This is described in more detail in the section on pleural reflections, but it is important to appreciate that:

• the inferior margin of the lung and visceral pleura is on average 2 ribs superior to the parietal pleura; this interval may increase to 3 ribs in children
• the anterior margin of the pleura is slightly superior to its posterior margin on each side
• the pleura are relatively unprotected in certain areas and are prone to being breached:
  • costovertebral angles e.g. by posterior approach nephrectomy
  • the right infrasternal angle e.g. by right subcostal incisions
  • cervical pleura superior to the first rib, e.g. by low neck wounds