These resemble blood-conducting veins but have thinner walls and relatively larger lumen, and they have more valves. In the skin, lymphatics are located in subcutaneous tissue and follow same paths as veins. At certain locations lymphatics enter lymph nodes. These are structures that consist of lymphatic tissue. As the lymph flows slowly through the lymph sinuses within the tissue of the lymph node, it is filtered.
Macrophages remove bacteria and other foreign matter as well as debris.
Lymphocytes are added to the lymph as it flows through the sinuses of a lymph node. Thus the lymph leaving the node is both cleaner of debris and richer in lymphocytes. Lymphatics leaving lymph nodes are called efferent lymph vessels and conduct lymph toward the shoulder region. Large lymphatics that drain groups of lymph nodes are often called lymph trunks. Lymphatics from the lower portion of the body converge to form a dilated lymph vessel, the cisterna chyli, in the lumbar region of the abdominal cavity.