Answer
The two muscle of the testes are the dartos muscle and the cremaster muscle. The dartos muscle consists of smooth muscle fibers within the septum of the testis and in the subcutaneous layer of this organ. The cremaster comprises bundles of skeletal muscle fibers which pass through the spermatic cord to surround the testis.
Work Step by Step
Optimum temperature for sperm production is 95-97 degrees Fahrenheit, two to thee degrees below normal body temperature. Because the testes are outside the pelvic cavity, this lower temperature is usually normally maintained . However, if temperature around the testes falls below the optimal range, the testes are drawn up closer to the body to benefit from its warmth. This pulling up of the testes is effected by contraction of the cremaster muscle. If the testis get too warm the cremaster relaxes and the testes cool as they move away from the body. The dartos muscle also contributes to maintaining the temperature homeostasis of the testes. When the dartos contracts and tightens around the testis this increases heat loss and helps to lower the temperature of the gonad. This effect is reversed when the dartos relaxes.
