Lymphatics of the mediastinum
After going through this study unit you will be able to:
- Identify the thoracic duct and other major lymphatic vessels of the mediastinum.
- Describe the main groups of lymph nodes of the mediastinum.
The mediastinum is a space located in the middle of the thoracic cavity, between the two pleural cavities. It can be divided into two main divisions (superior and inferior) that contain many vital structures, such as the heart and great vessels. Like all organs, these structures need to be drained by components of the lymphatic system.
The mediastinum contains several aggregations of lymph nodes which can be broadly categorized into three groups: anterior, intermediate (tracheobronchial) and posterior. As with all lymph nodes in the body, these node groups are ultimately drained into large thoracic lymphatic vessels (thoracic duct/right lymphatic duct) which terminate at the junction of the subclavian and internal jugular veins.
Given their close proximity and common drainage pathways, the lymph nodes of the thoracic wall (a.k.a. parietal thoracic lymph nodes) will also be evaluated in this section..
If you want to explore the major lymphatic vessels and lymph nodes of the mediastinum, take a look at the video below!
Take a quiz
Learning about lymphatics may not be as difficult as you thought! Test your knowledge on the lymphatics of the mediastinum with the quiz below.
Customize your own quiz and evaluate your broader understanding of the structures of the mediastinum here.
Take a closer look at the lymph nodes and vessels of the mediastinum in the gallery below.
|Main lymphatic vessels
Thoracic duct: Drains most of the mediastinal organs via left bronchomediastinal lymphatic trunk (as well as the majority of the body, except for regions received by right lymphatic duct listed below)
Right lymphatic duct: Drains left side of the heart, right lung, lower lobe of left lung, right side of the thorax via right bronchomediastinal lymphatic trunk (as well as right side of the head and neck and right upper limb)
|Main groups of lymph nodes
Brachiocephalic lymph nodes: Drain thymus, thyroid glands, pericardium and right side of heart → ipsilateral bronchomediastinal lymph trunk
Posterior mediastinal lymph nodes: Drain esophagus, posterior pericardium, and posterior surface of the diaphragm → thoracic duct
Paratracheal lymph nodes: Drain lungs, larynx, laryngopharynx, trachea, thyroid gland, and esophagus → ipsilateral bronchomediastinal lymph trunk
Superior and inferior tracheobronchial lymph nodes: Drain bronchi and lungs (receives lymph from the intrapulmonary and bronchopulmonary nodes), left side of heart → paratracheal lymph nodes
Intercostal lymph nodes: Drain posterolateral part of thoracic wall, parietal pleura and breasts as well as vertebral column and deep muscles of back
Superior phrenic lymph nodes: Drain diaphragm, pericardium, diaphragmatic pleura, and lowest intercostal spaces