The thickest nerve of the body is:
Sciatic nerve (L4-S3) is the largest peripheral nerve in the body.It is the longest and widest single nerve in the human body, going from the top of the leg to the foot on the posterior aspect The sciatic nerve is comprised of the tibial and common peroneal nerve and exits the pelvis inferior to the piriformis muscle, between the ischial tuberosity and the greater trochanter of the femur. Ref: Moon D.A., Foreman K.B., Albeine K.H. (2011). Chapter 12. Pelvis and Perineum. In D.A. Moon, K.B. Foreman, K.H. Albeine (Eds), The Big Picture:
Radial
Median
Sciatic
Axillary