Tunica dartos
The tunica dartos (from ancient Greek δαρτός dartos , German `` skinned, like raw meat '' ) is, in men, a thin layer of smooth muscle fibers in the penile foreskin , the shaft skin of the penis and in the skin of the scrotum and, in women, in the large labia . In the scrotum, it regulates the temperature of the testicles , which must be 2 to 3 ° C colder than the core of the body to produce fertile sperm . If the muscle layer of the scrotum contracts, the skin becomes wrinkled and the surface area smaller, which means that less body heat is lost and the testicles become warmer. Conversely, the slackening of the tunica dartos leads to a larger surface area of the scrotum and thus to a cooling of the testicles. The testicular lifter muscle is used in a similar way to regulate the temperature of the testicles.
The tunica dartos is innervated via α1-adrenergic synapses of the sympathetic fibers of the genital branch of the genitofemoral nerve .
In older men, the muscle tone of the tunica dartos can decrease, so that the scrotum hangs lower.
literature
- Uwe Gille: Male sexual organs. In: Franz-Viktor Salomon, Hans Geyer, Uwe Gille (Ed.): Anatomy for veterinary medicine. 2nd, revised and expanded edition. Enke, Stuttgart 2008, ISBN 978-3-8304-1075-1 , pp. 389-403.