Page 272 - Clinical Anatomy

ECA4 7/18/06 6:48 PM Page 257

Course and distribution of nerves 257

Fig. 185◊The segmental
cutaneous nerve supply
of the skin.

•◊◊L5—supplies the frontolateral aspect of the leg but also extends on to the
medial side of the foot;
•◊◊S1—supplies the lateral side of the foot and the sole;
•◊◊S2—supplies the posterior surface of the leg and thigh;
•◊◊S3 and 4—supply the buttocks and perianal region.
A little aid to memory is that 5 supplies the 1st toe and 1 supplies the
5th.
Note that although S3 supplies the posterior part of the scrotum (or
vulva), L1 supplies the anterior part of these structures via the ilio-inguinal
nerve.