Expansion
Parietal nodes drain the wall; visceral nodes drain the organs
Expansion
Parietal (drain the thoracic wall)
- Parasternal (internal thoracic) - anterior chest wall, medial breast, upper anterior abdominal wall
- Intercostal - posterior chest wall and pleura
- Diaphragmatic (phrenic) - diaphragm, pericardium and the superior surface of the liver
Visceral (drain the mediastinal organs)
- Brachiocephalic - thymus, thyroid, pericardium
- Posterior mediastinal - oesophagus, pericardium, diaphragm
- Tracheobronchial - lungs, bronchi, trachea and heart
All eventually drain into the bronchomediastinal trunks, and from there to the thoracic duct on the left and the right lymphatic duct on the right.
The diaphragmatic group explains a clinically useful route: infection or tumour on the upper surface of the liver can reach thoracic nodes directly, bypassing the abdomen.