Surah 86. At-Tariq, Ayah 7

The plural noun tara'ib, rendered by me as "pelvic arch", has also the meaning of "ribs" or "arch of bones"; according to most of the authorities who have specialized in the etymology of rare Qur'anic expressions, this term relates specifically to female anatomy (Taj al-'Arus).

 Testes and ovaries are formed in the abdomen of the fetus during the first weeks of pregnancy, before descending to their permanent place in the pelvis. Both are sustained by arteries originating between the backbone and the ribcage.

A man's seed is the quintessence of his body. It proceeds from his loins, i.e., from his back between the hip-bones and his ribs. His back-bone is the source and symbol of his strength and personality. In the spinal cord and in the brain is the directive energy of the central nervous system, and this directs all action, organic and psychic. The spinal cord is continuous with the Medulla Oblongata in the brain.