Cremasteric fibers/fascia

Definition

The cremaster muscle is skeletal muscle formed from fascicles of the internal oblique muscle that run with the spermatic cord.  The cremaster is responsible for raising and lowering the testis as part of their thermoregulation.  The muscle is not continuous around the spermatic cord, and in those region with no muscle fascicles there is a cremasteric fascia.

Clinical Note

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 the superior and medial (inner) part of the thigh - regardless of the direction. The normal response is an immediate contraction of the cremaster muscle that pulls up the testis ipsilaterally (on the same side of the body). 

Testing for the cremasteric reflex is a frequently used “special test” to help diagnose a particular condition or injury, similar to the “Apley scratch test” which is used to assess shoulder range of motion and flexibility. 

In young males, this reflex may be exaggerated which can occasionally lead to a misdiagnosis of cryptorchidism. 

In males with testicular pain, the absence of this reflex indicates testicular torsion which is a medical and surgical emergency.