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).
The hypothalmus gland. The pituitary gland controls body temperature. The hypothalamus is part of the brain (not a gland), and the pituitary gland is a protrusion off the bottom of the hypothalamus at the base of the brain. Melissa Shields.