If muslims believed that semen is produced in the backbone, why

they didn't believe semen is produced in the backbone, read again

>>3050159
there are multiple theories about this and these words in arabic can mean a lot more than just that
one theory is that al sulb( the hard) and al taraab (basically the soft) refer to the sexual organs of a man and a woman
another theory was "gushing fluid poured forth" refers to the aorta which according to a book cited by him(Jamal Badawi), Clinical Anatomy, supplies the testes and ovaries with the necessary nutrients and this is what the Quran refers to