Final answer:
The first lymph node that drains lymph from the testis is the para-aortic lymph nodes.
Step-by-step explanation:
The first lymph node that lymph from the testis drains into is the para-aortic lymph nodes. When lymph is drained from the testes, it travels through the spermatic cord, with the right testicular vein emptying into the inferior vena cava and the left into the left renal vein. The lymphatic fluid then moves into the para-aortic lymph nodes, which are positioned around the abdominal aorta, specifically around the area of the renal veins which receive the drainage from the left testicular vein. The first lymph node that lymph from the testis drains into is the inguinal lymph nodes. The lymphatic vessels from the testes travel through the inguinal canal and reach the inguinal lymph nodes, which are located in the groin area.