Final answer:
The majority of cutaneous lymph from the umbilicus down drains to the superficial inguinal lymph nodes with exceptions where the skin around the anus below the dentate line drains to the internal iliac lymph nodes and certain pelvic structures drain to the para-aortic nodes.
Step-by-step explanation:
The cutaneous lymph from the umbilicus down, including the area below the dentate line of the anus, primarily drains into the superficial inguinal lymph nodes. However, there are two exceptions to this drainage pattern: (1) The lymph from the area of the skin around the anus below the dentate line actually drains into the internal iliac lymph nodes. (2) The lymph from the testes, ovaries, and associated structures in both sexes, as well as the skin of the anus above the dentate line, drains into the para-aortic nodes due to their embryonic origin and descent.