** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. ** With a gun carried in the appendix ...

The testis, or testicle, is one of typically two oval-shaped endocrine glands that form part of the male reproductive system. The testes are the male homologues to the female ovaries, and their main ...

Ultrasound is produced by high frequency vibrations beyond the range of human hearing. The frequency of ultrasound is therefore greater than 20,000 hertz. Ultrasound, like audible sounds, is ...

Spermiation—the release of mature spermatozoa from Sertoli cells into the seminiferous tubule lumen—occurs by the disruption of an anchoring device known as the apical ectoplasmic specialization ...