Lymph of the lower lobe of the left lung passes through the nodes located at the base of the lower lobe bronchus and along the lower lobe artery, interlobar lymph nodes and reaches the area of the root of the lung. Here it is drained by the lymph nodes of the anterior and lower root groups mainly, heading to the bifurcation. From the bifurcation lymph nodes, its main quantity with an upward current passes through the left tracheobronchial and preaortocarotid lymph nodes, heading to the nodes of the left supraclavicular region and then to the venous system. A small amount of lymph flows to the esophageal lymph nodes, but then follows in an upward direction.
Thus, despite the existence of extensive connections throughout the lymphatic system of the lungs, including its mediastinal section, under normal conditions, the physiological lymphatic current stably maintains a rather pronounced directivity from the periphery to the center and in the ascending direction to the venous bed. It is regional in relation to each of the lobes of the lung, and within the mediastinum it stably correlates with the side of the corresponding lung. This is due to the fact that in normal living conditions of a healthy organism, in the absence of pathological changes in the regional lymphatic channel, the bulk of lymphatic vessels established during anatomical studies is in a state of physiological rest and is functionally inactive. Only in special cases (increased functional loads, the appearance of obstacles to the normal outflow) do additional, reserve and bypass paths of lymph flow “turn on”. They can for quite a long time and sustainably support and maintain the progress of the lymph, without violating its regionality. In case of deeper, more extensive and progressive disorders in the lymphatic apparatus, compensation of lymph outflow is ensured by the formation of additional, newly formed lymphatic vessels. Then, for a certain time, the advancement of lymph is provided by vessels, which are often not regional for this department of the lung. In this case, lymph from one or another lobe of the lung can flow in an unusual direction: have a retrograde character, “bypass” the blocked areas of the lymphatic collector until it moves along the transverse lymphatic connections to the opposite side of the mediastinum.
A certain place in the formation of additional or new pathways of lymph outflow from the lungs under pathological conditions is occupied by lymphatic vessels, which form in long-existing joints that appear in the chest cavity after inflammatory processes that have been transferred in the past.