Levator testis muscle (M. Cremaster, Pna, Bna, Jna)
The levator testis muscle, also known as the cremaster muscle or Pna, Bna, Jna according to the list of anatomical terms, is an important structure in the male anatomy. This muscle is located in the scrotum and plays an important role in regulating the position and temperature of the testicle.
M. cremaster is a skeletal striate muscle that surrounds the spermatic cord (funiculus spermaticus), a structure containing the vas deferens and blood vessels running from the testicle to the perineum. It consists of fibers originating from the inner base of the abdomen and the prostate gland. M. cremaster fibers form circular spirals around the spermatic cord, forming a kind of sheath.
The function of the m. cremaster is to raise and lower the testicle in the scrotum. When the muscle contracts, it lifts the testicle closer to the body, allowing heat exchange and maintaining the optimal temperature for normal spermatogenesis. In the process of elevating the testicle, m. cremaster also helps to tighten the spermatic cord and its components.
Control of the muscle is carried out through nerve innervation. The fibers of the m. cremaster are innervated by nerves passing through the femoral collar cavity (lacuna vasorum femoris). These nerves originate from the inferior pubic nerve (n. ilioinguinalis) and the femoral nerve (n. genitofemoralis). Stimulation of these nerves causes the muscle to contract and raise the testicle.
In addition to its role in regulating testicular position, the levator testis muscle may also play a role in protecting the testicle. In the event of danger or potential injury, the cremaster muscle can reflexively contract, pulling the testicle closer to the body and reducing the risk of injury.
In conclusion, the levator testis muscle (M. Cremaster, Pna, Bna, Jna) is an important anatomical structure in the male anatomy. Its functions include regulating the position and temperature of the testicle, as well as protecting against potential damage. Understanding this muscle and its role in the body can be useful for doctors and researchers interested in male anatomy and reproductive health.