Melasma Overview. Patches of melasma are darker than other areas of skin because they have more pigment. The cells that produce pigment in the skin are called melanocytes. Ultraviolet radiation, or UV rays, from the sun stimulate melanocytes to produce pigment.
The human testicle .The two muscles that regulate the temperature of the testes are the dartos andcremaster muscles:â¢ Dartos Muscle The dartos muscle is a layer of smooth muscle fibers in the subcutaneous tissue of thescrotum (surrounding the scrotum).
Best Answer: B. In order for testes to produce sufficient quality and quantity of sperm, the temperature of testes must be lower than the core body temperature. Being outside of the body cavity allows the testes to remain a little cooler than the rest of the body. Source(s):