Which nerve of the sacral plexus is the largest and longest nerve in the body?

• A. Sciatic nerve
• B. Pudendal nerve
• C. Obturator nerve
• D. Femoral nerve

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by understanding the sacral plexus, which is a network of nerves located in the pelvis. It provides motor and sensory innervation to the lower limbs and pelvic region.
2. Step 2: Recall that the largest and longest nerve in the human body is responsible for transmitting signals to and from the lower limbs, including the thigh, leg, and foot.
3. Step 3: Review the functions of the listed nerves: The sciatic nerve is the largest and longest nerve, extending from the sacral plexus down the posterior thigh and branching into the tibial and common fibular nerves. The pudendal nerve primarily serves the perineum. The obturator nerve innervates the medial thigh muscles. The femoral nerve serves the anterior thigh muscles.
4. Step 4: Compare the anatomical characteristics of the sciatic nerve with the other options. Note that the sciatic nerve's size and length make it unique among the listed nerves.
5. Step 5: Conclude that the sciatic nerve is the correct answer based on its anatomical significance and role in the sacral plexus.