Figure 1322

Schematic diagram of lymphocyte circulation within a lymph node.

The green arrows indicate the circulation pathway of lymphocytes that enter the lymph node with the flow of lymph. Afferent lymphatic vessels carry lymph from the surrounding tissues and neighboring lymph nodes into the elaborate network of lymphatic sinuses. The wall of the sinuses allows lymph to percolate freely into the superficial and deep cortex, allowing lymphocytes to engage in immunosurveillance. The lymphocytes that enter the tissue next migrate back to the sinuses and leave the lymph node with the flow of the lymph. Lymphocytes that migrate to the lymph node from the blood (blue arrows) enter the deep cortex via high endothelial venules (HEVs) and also migrate to the superficial cortex. Here, lymphocytes perform the same functions as lymphocytes that enter via lymphatic vessels. They also leave the lymph node by the efferent lymph vessels.

medulla medullary sinus efferent lymph vessel n from

V lymph n from

V blood subcapsular trabecular sinus medulla germinal •.•.':• center medullary sinus efferent lymph vessel

0 0

Post a comment