Anatomy word of the month: cremaster

To “suspend or hang” in Greek.  In the male body, the cremaster is part of a mechanism to suspend the testes in a special pouch, the scrotum.  Why do the testes reside in a special pouch outside the body proper? The production of sperm is a heat sensitive process.  In fact, normal sperm will not be produced at normal body temperature of 98.6 F.  The testes require an environment that is 1-2 degrees cooler.  The scrotum, a pouch of skin and connective tissue, provides that environment.  However, daily environmental temperature changes requires fine tuning of scrotal temperature.  So, the cremaster, a sheath of connective tissue and muscle fibers derived from the inguinal region (the groin) of the abdomen, helps regulate testicular temperature.  When the environment gets too warm, the cremaster lets out some slack causing the testes to hang lower in the scrotum further away from the core body temperature.  When surroundings get too cold, the cremaster pulls up the testes closer to the abdominal wall to keep them warmer.