Final answer:
The superficial inguinal lymph nodes are divided into two groups: one located above the inguinal ligament (horizontal or superomedial group) and another below it (vertical or inferolateral group), both with significant roles in lymph drainage.
Step-by-step explanation:
The superficial inguinal lymph nodes are divided into two groups, with each serving as a crucial part of the lymphatic system. One group is located above the inguinal ligament and is responsible for draining lymph from areas such as the integument of the lower abdomen, buttocks, external genitalia, and the lower part of the canal. This grouping is often referred to as the horizontal or superomedial group. The second group is found beneath the inguinal ligament and collects lymph from the lower limbs. It is also associated with the great saphenous vein and is referred to as the vertical or inferolateral group.In a lymph node, such as the ones in the inguinal region, we identify a structural organization that is very similar across lymph nodes. The subcapsular sinus is a space beneath the capsule where lymph enters via afferent lymphatic vessels. Within the node, there are germinal centers packed with proliferating B cells, surrounded by layers of T cells and other cells. The figure from the University of Michigan Medical School illustrates these details, indicating the complex histology and structure of a lymph node.Lymphatic fluids and cells leave the lymph node through efferent vessels, ultimately joining to create lymphatic trunks. The lymphatic trunks come together and then drain into the subclavian veins on either side of the body—the right lymphatic duct on the right, and the thoracic duct on the left side.