Okay, let's tackle this question about the lymphatic drainage of the spongy urethra. First, I need to recall the anatomy of the male genital system, specifically the lymphatic pathways. The spongy urethra is part of the male urethra that runs through the corpus spongiosum. Lymphatic drainage patterns are crucial in cancer staging, so this is probably a clinically relevant question.

The core concept here is the lymphatic drainage of the genitourinary system. The spongy urethra's lymphatics would drain into specific lymph nodes. I remember that different parts of the urethra have different drainage. The spongy (penile) urethra's lymphatics typically drain into the superficial inguinal lymph nodes. Wait, but maybe some go to the internal iliac nodes? Or perhaps the external iliacs?

Let me think again. The penile lymphatics, including the spongy urethra, usually drain into the superficial inguinal lymph nodes. The superficial inguinal nodes receive lymph from the scrotum, penis, and the lower part of the abdominal wall. Then, the efferent lymphatics from these nodes go to the deep inguinal nodes, and from there, they might enter the external iliac lymph nodes. But the primary drainage for the spongy urethra is the superficial inguinal nodes.

Now, the incorrect options might include the internal iliac nodes, which are more for pelvic organs, or the obturator nodes, which are part of the pelvic lymphatic system. The external iliac nodes might be a distractor, but the main ones here are the superficial inguinal nodes. So the correct answer should be superficial inguinal lymph nodes.

Wait, but I need to make sure. Let me cross-check. The spongy urethra is in the penis, so its lymphatics would follow the penile drainage. Yes, the superficial inguinal nodes are the primary. If there's a question about the membranous urethra, it might go to the internal iliacs. So in this case, the answer is superficial inguinal lymph nodes. The other options would be incorrect because they're either deeper or related to different parts of the urinary system.

Clinical pearl: Remember that the spongy urethra's lymphatic drainage is to the superficial inguinal nodes, which is important in staging penile cancer. This is a high-yield fact for exams because it's a common question point. Also, the membranous urethra drains to pelvic nodes, so differentiating between the two parts of the urethra is key.

**Core Concept:** The lymphatic drainage of the spongy urethra is critical for understanding metastatic pathways in urological malignancies. The spongy urethra (penile urethra) drains to superficial inguinal lymph nodes, while the membranous urethra drains to internal iliac nodes. This distinction is vital for staging penile or urethral cancers.

**Why the Correct Answer is Right:** The spongy urethra is anatomically contiguous with the penile tissues. Its lymphatics follow the superficial penile lymphatic network, which drains to **superficial inguinal lymph nodes** (first-order nodes). Efferent lymph

✓ Correct Answer: C. Deep inguinal nodes