Cremasteric reflex

Area A (in orange) represents the area of sensory fibers controlled by the genitofemoral nerve; area B (in green) represents that controlled by the ilioinguinal nerve; arrow C (in red with blue outline) shows the location where the skin must be stroked to elicit this reflex.
Cremasteric reflex

The cremasteric reflex is a superficial (i.e., close to the skin's surface) reflex observed in human males.

This reflex is elicited by lightly stroking or poking the superior and medial (inner) part of the thigh—regardless of the direction of stroke.[1] The normal response is an immediate contraction of the cremaster muscle that pulls up the testicle ipsilaterally (on the same side of the body). The reflex utilizes sensory and motor fibers from two different nerves. When the inner thigh is stroked, sensory fibers of the ilioinguinal nerve are stimulated. These activate the motor fibers of the genital branch of the genitofemoral nerve which causes the cremaster muscle to contract and elevate the testis.[2]: 262 

  1. ^ "Definition: cremasteric reflex from Online Medical Dictionary". Archived from the original on 2007-08-13. Retrieved 2007-12-06.
  2. ^ Drake, Richard L.; Vogl, Wayne; Tibbitts, Adam W.M. Mitchell; illustrations by Richard; Richardson, Paul (2005). Gray's anatomy for students (Pbk. ed.). Philadelphia: Elsevier/Churchill Livingstone. ISBN 978-0-443-06612-2.