Which lymph node group drains all skin from the umbilicus downward, including the anus, but excludes the testes and posterior calf?

Which lymph node group drains all skin from the umbilicus downward, including the anus, but excludes the testes and posterior calf?

• A. Deep inguinal nodes
• B. Popliteal nodes
• C. Lumbar nodes
• D. Superficial inguinal nodes

Answer: (D)

Lymphatics of the skin in the lower trunk and perineal region converge on the superficial inguinal nodes. These nodes collect cutaneous drainage from the lower abdominal wall below the umbilicus, the buttocks, perineum, and the external genitalia, including the anal canal below the pectinate line. The testes have their own separate drainage path to the lumbar (para-aortic) nodes, not to these superficial inguinal nodes. Likewise, the posterior calf mainly drains to the popliteal nodes (and then to deeper groups), not primarily to the superficial inguinal nodes. So the group that matches “skin from the umbilicus downward, including the anus, but excluding the testes and posterior calf” is the superficial inguinal nodes.

Lymphatics of the skin in the lower trunk and perineal region converge on the superficial inguinal nodes. These nodes collect cutaneous drainage from the lower abdominal wall below the umbilicus, the buttocks, perineum, and the external genitalia, including the anal canal below the pectinate line. The testes have their own separate drainage path to the lumbar (para-aortic) nodes, not to these superficial inguinal nodes. Likewise, the posterior calf mainly drains to the popliteal nodes (and then to deeper groups), not primarily to the superficial inguinal nodes. So the group that matches “skin from the umbilicus downward, including the anus, but excluding the testes and posterior calf” is the superficial inguinal nodes.