Corpus: Cremaster muscle

The cremaster muscle is a loop-shaped muscle made up of fibers from the abdominal musculature that surrounds the spermatic cord and elevates the testicle when contracted.

The cremaster muscle is composed of fibers originating from the internal oblique and transverse abdominal muscles. These fibers run along the spermatic cord, forming loops that insert into the spermatic cord itself and into the testis, specifically the tunica vaginalis testis. The muscle is innervated by the genital branch of the genitofemoral nerve.

The cremaster muscle contracts in response to stimuli such as cold, pulling the testicles towards the body in the cremaster reflex. This contraction helps regulate testicular temperature, maintaining an optimal environment for sperm production.